Article

Soil erosion under the impacts of future climate change: Assessing the statistical significance of future changes and the potential on-site and off-site problems

Authors:
To read the full-text of this research, you can request a copy directly from the author.

No full-text available

Request Full-text Paper PDF

To read the full-text of this research,
you can request a copy directly from the author.

... Soil erosion is a serious environmental hazard to long-term sustainability and productivity, with implications for the climate crisis and food security (Benavidez et al., 2018;Koirala et al., 2019;Mullan, 2013). Wind, precipitation, associated runoff mechanisms, vulnerability to soil erosion, land use as well as management characteristics all influence soil erosion (Benavidez et al., 2018). ...
... Over the last few years, global climate predictions and their potential environmental impacts have become an increasing concern (Andrade et al., 2021). In reverse, it is possible to quantify future soil erosion by projecting potential future changes in rainfall erosivity (Mullan, 2013;Sardari et al., 2019). This projection is realized using precipitation data from the General Circulation Models (GCMs) which general provide global data at a coarse resolution (grid size approximately 100-200 km) (Piani et al., 2010;Teutschbein and Seibert, 2012). ...
... Climate change and extensive agriculture have been linked to increased soil erosion due to increased erosive power of precipitation and changes in biomass cover in previous research (Girmay et al., 2021;Koirala et al., 2019;Mullan, 2013). According to Borrelli et al. (2020), by 2070, there will be a strong trend to increase from 30% to 66% worldwide. ...
Article
In this study, the climate and land use change impact on soil water erosion in Loukkos watershed (northwestern Morocco) was assessed. This watershed is known by its intense agricultural activity and characterized by a Mediterranean climate. In order to quantify soil erosion, RUSLE model was used, combined with remote sensing and GIS technology under current and future climate scenarios predicted by the model CNRM-ALADIN63 for 2025–2055. The precipitation for the future climate period (2025–2055) was downscaled using CMhyd's statistical downscaling model (quantile-quantile). The results showed that the annual soil erosion rate averaged about 3.0 t, with a standard deviation of 6.2. In contrast, soil loss of less than 10 t ha−1 yr−1 occurred in 92% of the watershed. While overall erosion estimates show a medium erosion risk, attention and use of soil conservation practices is suggested for 7.1% of area has experienced soil erosion greater than 10 t ha−1 yr−1 . Furthermore, the results revealed that average annual soil loss could increase by 3.9% and 8.4% respectively for medium and high Representative Concentration Pathways (RCP 4.5 and RCP 8.5) compared to the baseline period (1981–2017). Soil erosion assessment and land use change were determined to help implement future conservation measures for decision makers to develop appropriate strategies for long-term planning of water and soil resources, risk mapping and agriculture under various climate change scenarios.
... This response option has been assessed as having low current applicability for Ireland, due to the relatively low levels of soil erosion incurred (Table A1.1). However, this assessment is limited by a lack of national-level measured data on rates of soil erosion in Ireland (Mullan, 2013). ...
... Ireland revealed a relatively large range from 0.07 to 4.09 t ha -1 yr -1 (Mullan, 2013). Putting the rate of soil erosion into context requires consideration of the rate of soil formation and in general a loss of soil greater that 1.0 t ha -1 yr -1 is accepted to be irreversible over a 50 to100-year period (Jones et al., 2004). ...
Technical Report
Full-text available
This supplement provides additional information to EPA Research Report No. 371: Climate Change and Land Use in Ireland (Haughey, 2021). Specifically, this supplement provides further background to Chapter 4 of the main report: Integrated Response Options and its assessment of forty integrated response options.
... Land conversion causes land degradation [1]. The increase in human population and changes in human lifestyles have caused pressure on the land because resources are over-exploited. ...
... Human population and lifestyle cause pressure on the land so that land functions change. Transfer of land function causes erosion [1]. In addition to these factors, physical factors of land also cause erosion, especially in soil types [6]. ...
... For example, Eekhout and De Vente (2019) modelled two Mediterranean catchments using models forced by rainfall (Revised Universal Soil Loss Equation, RUSLE), runoff (Modified Universal Soil Loss Equation, MUSLE) or both (Morgan Morgan and Finney, MMF) and found that soil erosion is projected to decrease (RUSLE) or increase (MUSLE and MMF) depending on which model is used, because in the study catchment rainfall was projected to decrease but extreme precipitation events were projected to increase. Similarly, Mullan (2013) found that modelling of six hillslopes in Northern Ireland using the Water Erosion Prediction Project model gave both soil erosion increases and decreases depending on which climate change scenario was used. Climate change is also predicted to significantly increase the rates of shallow landslide erosion where it increases the frequency and intensity of severe rainfall events (Crozier 2010;Gariano and Guzzetti 2016) New Zealand has naturally high erosion rates as a result of a predominance of steep slopes, high rates of tectonic activity and volcanism, generally high rainfall, and common high-intensity rainstorms, as well as relatively recent deforestation of much of the country (Basher 2013). ...
... The results are similar to those found in other countries, both in terms of the likely trend in erosion and sediment load (Yang et al. 2003;Nearing et al. 2004;Gariano and Guzzetti 2016) and the variation and uncertainty in the predictions depending on choice of GCMs and climate change scenarios (Mullan 2013;Eekhout and De Vente 2019). While the absolute magnitude of change in erosion and sediment load remains uncertain, there is sufficient confidence in the direction of change from the modelling predictions to suggest land and river management in New Zealand will need to continue to develop strategies to offset these changes and manage the environmental and engineering hazards associated with them. ...
Article
SedNetNZ is used to model the effect of erosion control undertaken under the Sustainable Land Use Initiative (SLUI) and predict the effect of climate change on sediment load in the Manawatū–Whanganui region. Sediment load in 2004 is estimated at 13.4 Mt yr⁻¹; by 2018, ≈5000 km² of land had farm plans implemented and annual sediment load reduced by 6.2% of the 2004 load. If SLUI stops at the 2018 level of implementation, by 2038 it is predicted to achieve a 15.7% reduction in annual sediment load. If SLUI continues to implement farm plans, 7949 km² of land will be treated by 2043 and annual sediment load could be reduced by a further 14.7%. Climate change is predicted to substantially increase sediment loads. By 2043 annual sediment load for the region is predicted to increase, compared to 2004, by between 8.3 and 23.7%. However, this can largely be offset by SLUI works. By 2090 an annual sediment load increase of between 53 and 224% due to climate change is predicted. The results suggest climate warming may dominate changes in sediment load in the future.
... This response option has been assessed as having low current applicability for Ireland, due to the relatively low levels of soil erosion incurred (Table A1.1). However, this assessment is limited by a lack of national-level measured data on rates of soil erosion in Ireland (Mullan, 2013). ...
... Ireland revealed a relatively large range from 0.07 to 4.09 t ha -1 yr -1 (Mullan, 2013). Putting the rate of soil erosion into context requires consideration of the rate of soil formation and in general a loss of soil greater that 1.0 t ha -1 yr -1 is accepted to be irreversible over a 50 to100-year period (Jones et al., 2004). ...
Technical Report
Full-text available
This report translates key findings from the International Panel on Climate Change (IPCC) Special Report on Climate Change and Land (SRCCL) into the context of the Irish land system. The SRCCL is particularly relevant for Ireland because of the specific challenges to climate change mitigation and adaptation presented by the country’s land system and land use. This report informs policy in relation to the scale of these challenges. It identifies pressures in terms of greenhouse gas (GHG) fluxes from the land system and how these emissions relate to land use and its economic outputs. Finally, the report focuses on solutions in the form of an assessment of actions that can be taken to simultaneously address climate mitigation and adaptation in the land system. Knowledge gaps are identified and recommendations for future research are made. Although land use in Ireland is dominated by grassland (61.0% in 2016) and related grassland-based agriculture, there is significant variation in the intensity of grassland management across farming systems. Economically, agricultural outputs are dominated by ruminant livestock in the form of dairy and beef production. However, pigs, cereals (barley, wheat and oats), sheep, poultry, potatoes and mushrooms are also important. The area of forestry in Ireland has increased dramatically over the last century, from around 1.4% in 1918 to around 10.7% in 2016. However, the forest area remains relatively low compared with the average for the first 28 Member States of the EU (EU-28), and the rate of afforestation has slowed in recent decades. Peatlands cover a significant area but are largely degraded by human activities such as peat extraction. A national land use map, including data on land use intensity, would enable a better understanding of the dynamics of the land system in Ireland and facilitate targeted implementation of actions. Current data on the principal land-based GHGs – carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) – were summarised and assessed. Over the period 2010–2017, agriculture contributed 28.8% of GHG emissions in Ireland, a substantially larger portion than the EU-28 average over the same period (10.3%). This contrast was driven by the dominance of ruminant livestock production and a relatively low level of heavy industry in Ireland. Again in contrast to the EU-28, the land use, land use change and forestry (LULUCF) category was a net source of GHGs in Ireland between 2010 and 2017. Agricultural emissions are dominated by CH4 emissions from ruminant livestock and manure management and by N2O emissions resulting from fertiliser use and soil management. Despite improvements in production efficiency in the agriculture sector, expansion and intensification have led to increases in absolute GHG emissions over the last decade. Forestry is an important net carbon sink, but its contribution is likely to decline in the coming decades as the rate of afforestation is decreasing. Peatlands and organic soils under agricultural management are significant GHG sources, but there is large uncertainty regarding actual GHG emissions from these lands, and their extent and drainage status represents a key knowledge gap. The potential of 40 integrated response options to contribute to climate mitigation and adaptation and other land system challenges was assessed for Ireland, with 12 of the options found to be highly applicable. Options considered highly applicable in terms of potential to mitigate climate change, particularly at an individual consumer level, include dietary change, such as a shift towards “sustainable healthy” diets, and a reduction in food waste. Actions aimed at increased food productivity and improved grazing land and livestock management also have high potential but could lead to “rebound effects” in terms of absolute environmental footprint. Agroforestry and agricultural diversification are highly applicable, yet these options face considerable barriers to uptake by landowners, and a review of current policies is recommended. Although afforestation and bioenergy have considerable mitigation potential, they could have negative impacts on biodiversity and increase land competition if implemented at large scales. The restoration of peatlands and organic agricultural soils represents a major opportunity to reduce GHG emissions and create carbon sinks, but positive outcomes require major investment and may be limited by site-specific constraints. Biodiversity conservation goals may be more likely to succeed where integrated with land use planning including climate mitigation and adaptation strategies. Implementation of land-based response options requires a sustainable land management approach, one in which local communities and landowners are actively engaged in the planning and implementation process.
... Past research has shown that runoff derived from infrequent extreme storms that occur during the crop growing season will strip fertile topsoil, which causes a decrease in crop productivity (Savabi and Stockle, 2001;Yuan et al., 2016). Elevated CO 2 concentrations commonly lead to an increase of plant biomass owing to enhancing the water and energy use efficiencies of plants by lowering plant transpiration rates (Ciampalini et al., 2020), which increases canopy interception and creates more biological ground cover to promote water infiltration, reduces surface runoff, and mitigates soil erosion rates (Mullan, 2013). However, excessive temperature stresses from rising CO 2 concentration often lead to decreases in crop yield due to increased respiration loss and water stress (Pruski and Nearing, 2002). ...
... Few studies used more than ten GCMs/RCMs to assess soil erosion rate (de Vente and Eekhout, 2021;Li and Fang, 2016). Third, a small number of studies paid attention to the impact of cropping and tillage systems on soil erosion under climate change, but only accounted for a few combinations of crop types and tillage methods (Garbrecht and Zhang, 2015;Mullan, 2013;Zhang and Nearing, 2005;Zhang et al., 2012). Finally, uncertainty analysis of model simulations needs to be further strengthened. ...
Article
Proper simulation of storm intensification is critical in projecting crop yield, surface runoff, and soil loss under climate change conditions. We developed a total of 100 climate scenarios coupled with storm intensification, which were based on 25 downscaled GCMs (General Circulation Model) projections under RCP4.5 and RCP8.5 (Representative Concentration Pathways) for two time periods of 2021–2050 and 2051–2080. The climate files were applied to a modified WEPP (Water Erosion Prediction Project) model to estimate crop yield, runoff, and soil loss under 29 combinations of cropping and tillage systems. The results showed that future extreme storm events in the study area would significantly increase during 2021–2080 (P < 0.01). However, average monthly precipitation in summer would decrease by 12.5% in June and 10.8% in July, along with an annual precipitation decline of 2.6%, leading to a decrease in crop yield in this rainfed agricultural region. The amount of runoff (soil loss) from extreme storms would account for 45.9 (64.3%) of the total annual runoff (soil loss) when averaged across two time periods and two RCPs. The average annual runoff depth (soil loss amount) from crop rotation or double cropping systems would be 27.6 (78.1%) less than the corresponding values in a continuous monoculture cropping system. No-till and crop rotations with alfalfa are the best agricultural management alternatives to mitigate soil erosion rates under future climate change. The analysis of variance (ANOVA) indicated that the uncertainty contributions of GCMs and cropping and tillage systems reached 45.5% and 30.4% in annual surface runoff prediction (P < 0.001), while cropping and tillage systems (71.7%, P < 0.001) was the major uncertainty source in annual soil loss simulations. This study improved the prediction of crop yield, runoff, and soil loss from various cropping and tillage systems under climate change conditions by integrating storm intensification from multiple GCM ensembles.
... Potential impacts of climate change on water security include decreased quality and quantity of available water and increased inter-annual variability (Kusangaya et al., 2014;Seneviratne et al., 2012;Tabari, 2020); increase in drought intensity and return period (Davis-Reddy and Vincent, 2017;Tabari, 2020); and increased evapotranspiration (Wu et al., 2009). Yet, climate change is also projected to affect runoff and erosion rates (Nearing et al., 2004, Mullan et al., 2012, Mullan 2013Simonneaux et al., 2015). Direct impacts of climate change on soil erosion include variations in rainfall erosivity, temporal changes in rainfall, changes in soil moisture content, and changes in wind erosion (Mullan et al., 2012). ...
... It is widely accepted that climate change will bring about large changes in the hydrological cycle, most likely causing increased frequency and intensity of extreme rainfall events (Nearing et al., 2004;Seneviratne et al., 2012;Tabari, 2020). Numerous studies have shown that extreme rainfall events lead to increased runoff and sedimentation of reservoirs (Msadala et al., 2010;Mullan, 2013;Pretorius 2017). However, few studies have focused on the effects of climate change on sediment yield and erosivity, most notably in Africa (Nearing et al., 2004;Mullan et al., 2012;Simonneaux et al., 2015). ...
Article
Full-text available
The effects of climate change on water resources could be numerous and widespread, affecting water quality and water security across the globe. Variations in rainfall erosivity and temporal patterns, along with changes in biomass and land use, are some of the impacts climate change is projected to have on soil erosion. Sedimentation of watercourses and reservoirs, especially in water-stressed regions such as sub-Saharan Africa, may hamper climate change resilience. Modelling sediment yield under various climate change scenarios is vital to develop mitigation strategies which offset the negative effects of erosion and ensure infrastructure remains sustainable under future climate change. This study investigated the relative change in sediment yield with projected climate change using the Soil and Water Assessment Tool (SWAT) for a rural catchment in South Africa for the period 2015–2100. Data from six downscaled Coupled Global Climate Models (CGCM) were divided into three shorter time periods, namely, 2015–2034, 2045–2064 and 2081–2100. Results were then compared with a control scenario using observed data for the period 2002–2017. The results show that, if left unmanaged, climate change will likely lead to greater sediment yield, of up to 10% more per annum. Peak sediment yield will also increase almost three-fold throughout the century. The study shows that projected climate change will have multiple negative effects on soil erosion and emphasised the need for changes in climate to be considered when embarking on water resource developments.
... In modern times, the development of large-scale industry and agriculture has intensified the occurrence of soil erosion, causing sharp deterioration in the ecological environment, which severely restricts agricultural development and threatens the survival of humankind. There are many forms of soil erosion, and regional differences in climate characteristics, topography, and soil vegetation types result in different forms of soil erosion [1,2]. For example, the soil in the loess region of Northwest China tends to be loose, poorly agglomerated, and structurally unstable; thus, the soil can be susceptible to erosion due to rainfall and runoff [3]. ...
... Therefore, among the different soil types and different slopes, the level to which biochar decreases soil erosion differs. Moreover, soil erosion is greatly affected by climate conditions, especially under the effects of dramatic climate change, and the occurrence of soil erosion may be aggravated [2]. Compared with nonfrozen soil areas, in seasonally frozen soil areas with high latitude and high altitude, the free-thaw process may be an important process leading to soil erosion [49]. ...
Article
Full-text available
Biochar, as a kind of soil amendment, has attracted wide attention from scholars in various countries, and the effects of biochar on soil and water loss have been well reported. However, soil erosion is significantly affected by geographical conditions, climate, and other factors, and research on the characteristics of soil erosion and the effects of biochar application in seasonally frozen soil areas is currently unclear. The purpose of this study was to explore the effect of corn straw biochar application on soil and water conservation during the spring thawing period. Specifically, through field experiments, the addition of 0, 6, and 12 kg m−2 biochar on slopes of 1.8, 3.6, 5.4, and 7.2° and the effects on runoff and the soil erosion rate of farmland were analyzed. The results showed that in the 6 and 12 kg m−2 biochar addition treatments, the saturated water content of the soil increased by 24.17 and 42.91%, and the field capacity increased by 32.44 and 51.30%, respectively. Compared with the untreated slope, with an increase in biochar application rate, runoff decreased slightly, and soil erosion decreased significantly. This study reveals that biochar can be used as a potential measure to prevent soil and water loss on sloping farmland in cold regions.
... The description of the quantitative probability of tributary network in relation to the forthcoming changing climate is published only in 1 study which was done in England (Lane et al., 2007), which shows that variations in residue distribution to the canal possibly will vital than the fluctuations in hydrology pattern of the stream. Many studies (Coulthard et al., 2012;Mullan, 2013;Mullan et al., 2012), have been described, that increases in precipitation events increase the erosional process of the soil, in turn, the transfer of sediments also raises. For ponds and lagoons, amplified destruction of soil tends to increase in gathering rate of deposits and the hastening of hydro seral expansion, particularly in the coastal region. ...
Chapter
Full-text available
Water is the critical ingredient to all life on the earth, and it is without substitutes. With increasing demands and only a limited supply, freshwater is becoming more and more difficult to come by. Climate change can be defined as the change in time variation of weather over a time period. It is caused due to increasing the temperature, evaporation, precipitation, wind, and variation in solar radiation and human activities also identify the cause of climate change. Climate change identifies one of the major global challenges in the 21st century and its effects on the availability of freshwater. There are several effects of climate changes such as the increase in temperature (increase rate of evaporation, forest fire), melting of ice (increase in flood, adverse effect the migration of fishes) and sea-level rise, the decline in freshwater availability. Many studies have shown climatic change and its impact on the availability of freshwater. The freshwater ecosystem is warming, acidifying, and deoxygenating the consequences of climate change. It experiences low oxygen demands, low pH, and thermal stratification of freshwater.
... This is best illustrated in the cluster of high erosion rates in eastern Scotland visible in Fig. 2, which result from a study over two winters, where only fields with significant erosion features were assessed (Watson and Evans, 1991). Consequently, developing a clear understanding of where the variability in UK soil erosion rates comes from is imperative, particularly given the increased likelihood of large scale rainfall/runoff events due to climate change (Favis-Mortlock and Mullan, 2011;Lee et al., 1999;Mullan, 2013;Nearing et al., 2004;Schaller et al., 2016). ...
Article
Full-text available
Accelerated soil erosion can result in substantial declines in soil fertility and has devastating environmental impacts. Consequently, understanding if rates of soil erosion are acceptable is of local and global importance. Herein we use empirical soil erosion observations collated into an open access geodatabase to identify the extent to which existing data and methodological approaches can be used to develop an empirically-derived understanding of soil erosion in the UK (by way of an example). The findings indicate that whilst mean erosion rates in the UK are low, relative to the rest of Europe for example, 16% of observations on arable land were greater than the supposedly tolerable rate of 1 t ha⁻¹ yr⁻¹ and maximum erosion rates were as high as 91.7 t ha⁻¹ yr⁻¹. However, the analysis highlights a skew in existing studies towards locations with a known erosion likelihood and methods that are biased towards single erosion pathways, rather than an all-inclusive study of erosion rates and processes. Accordingly, we suggest that future soil erosion research and policy must address these issues if an accurate assessment of soil erosion rates at the national-scale are to be established. The interactive geodatabase published alongside this paper offers a platform for the simultaneous development of soil erosion research, formulation of effective policy and better protection of soil resources.
... As noted in several studies Butler, 2005;Mullan, 2013;Mullan et al., 2012;Verstraeten et al., 2003), a range of future land use changes should also be included in future research investigating climate change impacts on soil erosion and MF. This will enable adequate stress-testing of the resilience and adaptation of current mitigation measures (e.g. ...
Preprint
Climate models consistently project large increases in the frequency and magnitude of extreme precipitation events in the 21st century, revealing the potential for widespread impacts on various aspects of society. While the impacts on flooding receive particular attention, there is also considerable damage and associated cost for other precipitation–driven phenomena, including soil erosion and muddy flooding. Multiple studies have shown that climate change will worsen the impacts of soil erosion and muddy flooding in various regions. These studies typically drive erosion models with output from a single climate model or a few models with little justification. A blind approach to climate model selection increases the risk of simulating a narrower range of possible scenarios, limiting vital information for mitigation planning and adaptation. This study provides a comprehensive methodology to efficiently select suitable climate models for simulating soil erosion and muddy flooding. For a study region in Belgium using the WEPP soil erosion model, we compare the performance of our novel methodology against other model selection methods for a future period (2081–2100). The main findings reveal that our methodology is successful in generating the widest range of future scenarios from a small number of models, compared with other selection methods. This represents a novel targeted approach to climate model selection with respect to soil erosion by water but could be modified for other precipitation–driven impact sectors. This will ensure a broad range of climate impacts are simulated so the best- and worst-case scenarios can be adequately prepared for.
... During past decades, a significant warming trend was detected in this region (Gong et al. 2013;Zhou et al. 2020). Under this condition, soil loss may change (Mullan 2013;Qadir et al. 2013;Li and Fang 2017). In recent years, although the impacts of land use change on sediment yield (SY) have been evaluated in the black soil region (Fang and Sun 2017;Fang 2017), and the impact of climate change on future runoff and SY was also studied (Li and Fang 2017), these studies do not consider their combined impact on water yield and SY. ...
Article
Full-text available
The impact of climate or land use change on hydro-sedimentological process has been widely studied. However, their combined and distinct impacts to catchment runoff and sediment yield (SY) have received comparatively little attention, which impedes decision makers to better manage land use. To that end, the spatially distributed TETIS model was adopted to estimate impacts of land use and climate change on runoff and SY during 1978–2014 in the Yian catchment of the black soil region, northeastern China. Results indicated that the scenario with only climate change increased water and SYs by 31.55% and 92.1%, respectively. The scenarios with the changes in land use in 1985, 1995, 2000 and 2010 increased water and SYs by 1.28% and 12.54%, respectively. With respect to the baseline period in 1978–1987, the average increased rates of water and SYs were 31.7% and 114.5%, respectively. The contributions by climate change were 99.5% for water yield and 69.2% for SY, respectively. This study indicated that rational configuration and management of land use can alleviate the adverse impact derived by climate change in the black soil region and similar regions all over the world.
... Climate change impacts on agricultural production may be affected by the soil degradation process (Mullan, 2013). For example, a rise in mean temperatures may increase soil water evaporation and soil carbon losses, which combined with a higher frequency of extreme rainfall events may increase soil erodibility and reduce soil fertility (Nearing, Pruski & O'neal, 2004;Lal, 2012) . ...
Article
Climatic change effects on crop yields are expected to be crop‐ and site‐specific. Here, DSSAT models were used to evaluate climatic change effects and mitigation strategies on maize and soybean yields in soils of the subtropical and semi‐arid region of Chaco. Simulations were performed for the DK747 and A8000 genotypes, calibrated for CERES‐Maize in a previous report and for CROPGRO‐Soybean in the present study, respectively. Both crops markedly differ in their response to climatic change and putative levels of atmospheric‐CO2 concentration. The observed significant reductions in maize yields in future climate scenarios (5 ‐ 42% compared to the baseline 1986‐2010) were more associated with increased temperatures that shortened the crop cycle than with water stress. Delaying the sowing date turned out to be a feasible strategy to mitigate this effect. Projected temperature increases are expected to play a secondary role in determining soybean yields. Instead, water stress will continue to be an important constraint to soybean yield in the context of global warming, but this effect is strongly affected by the rainfall regimes. Responses to raising CO2 levels were more pronounced in soybean (+10‐40%) than in maize (+2‐4%). Soil degradation exacerbated the negative effects of global warming on crop yields, especially on maize, which highlights the importance of soil conservation practices. The observed high interannual climatic variability and the different sensitivity of maize and soybean to climatic variables indicates that crop diversification would be the key to improve the resilience of the agrosystems under the future scenarios. This article is protected by copyright. All rights reserved
... (2004, Nudes ve Nearing (2011) gibi araştırmacılar tarafından yapılmıştır. İklim değişikliğinin erozyona etkileri ile ilgili uygulamalı araştırmalar ise oldukça sınırlı olmakla birlikte sayıları özellikle son yıllarda artış göstermiştir (Nearing, 2001;O'Neal, 2005;Zhang ve Nearing, 2005;Mullan vd., 2012;Mullan, 2013 (Şen, 2003;Karaca, 2008;Kaya, 2008;Kadıoğlu, 2009;Kadıoğlu, 2012) olmakla birlikte bu konuda uygulamalı bir çalışmaya rastlanmamıştır. Örneğin, iklim değişikliğinin erozyona etkilerinin araştırılması gerektiğine dikkat çeken Karaca (2008), yağışların miktar, enerji ve şiddetlerinin mekânsal ve zamansal dağılımlarındaki farklılaşmanın doğrudan iklimden kaynaklanan erozyonun değişmesine sebep olacağını vurgulamış, yağış şiddetlerindeki ve miktarlarındaki artışın toprak erozyonunu da arttırabileceğini belirtmiştir. ...
... Soil erosion is a major global environmental issues that limits socioeconomic and environmental sustainability [1]. Soil erosion is an important form of non-point source (NPS) pollution and a primary transport mechanism that introduces a large amount of sediment and nutrients into various water bodies, causing water environment deterioration and thus endangering public health [2][3][4]. Many challenges are associated with soil erosion, such as land resource destruction and frequent calamities [5]. ...
Article
Full-text available
As the most typical ecologically fragile area in South China, the Three Gorges Reservoir Area (TGRA) suffers from water and soil loss, which has threatened the local ecological environment. Understanding the spatial heterogeneity of soil erosion and exploring its determinants are of great significance in preventing soil erosion and maintaining ecological sustainability in the TGRA. This study investigates the spatial heterogeneity of soil erosion and quantitatively identifies the determinants in the TGRA based on the Chinese Soil Loss Equation (CSLE) and geographical detector method. This study concluded that the soil erosion status generally improved from 1990 to 2015, showing an increasing trend from 1990 to 2000 and a decreasing trend from 2000 to 2010. Slope, land use, and vegetation coverage were the dominant individual factors affecting soil erosion in the TGRA. For the interaction factor, the combinations of land-use type and slope and vegetation coverage and slope were the key determinants, explaining 68.7% and 63.1% of the spatial heterogeneity of soil erosion in the TGRA from 1990 to 2015, respectively. Moderate and higher levels of soil erosion occurred in areas where the slope was greater than 25°. Among the land-use types, dry land and bare land were prone to soil erosion. These findings reveal that land-use type and vegetation coverage should be considered for the effective prevention of soil erosion, and cultivation on sloped farmland should be prohibited, especially on slopes higher than 25° in the TGRA.
... The research of the climatic impact on soil erosion (Xiong et al., 2019) is typically based on erosion modelling techniques, of which extensive reviews are reported in Li and Fang (2016) and Pandey et al. (2016). Process-based models have been widely used in assessments of climate-driven impacts on soil erosion (e.g., Favis-Mortlock and Boardman, 1995;Luetzenburg et al., 2019;Mullan, 2013;Mullan et al., 2012;Nunes et al., 2013;Pastor et al., 2019, Routschek et al., 2014Serpa et al., 2015), including impacts on vegetation and on agricultural practices in different climates (e.g., Garbrecht and Zhang, 2015;Nearing et al., 2005;O'Neal et al., 2005;Pruski and Nearing, 2002a;Scholz et al., 2008;Nearing, 2005, Zhang et al., 2012). Despite of the large number of approaches existing for modelling erosion, process-based models are frequently uniquely suited for explicitly considering specific soil transport mechanisms and the impacts of climatic factors on soil hydrology (Guo et al., 2019). ...
Article
Simulations of 21st century climate change for Great Britain predict increased seasonal precipitation that may lead to widespread soil loss by increasing surface runoff. Land use and different vegetation cover can respond differently to this scenario, mitigating or enhancing soil erosion. Here, by means of a sensitivity analysis of the PESERA soil erosion model, we test the potential for climate and vegetation to impact soil loss by surface-runoff mechanisms to three differentiated British catchments. First, to understand general behaviours, we modelled soil erosion adopting regular increments for rainfall and temperature from the baseline values (1961-1990). Then, we tested future climate change scenarios adopting projections from UKCP09 (UK Climate Projections) under the IPCC (Intergovernmental Panel on Climate Change) on a defined medium CO2 emissions scenario, SRES A1B (Special Report on Emissions Scenarios, SRES: IPCC, 2000), at the horizons 2010-39, 2040-69 and 2070-99. Our results indicate that the model reacts to the changes of the climatic parameters and the three catchments respond differently depending on their land use arrangement. Increases in rainfall produce a rise in soil erosion while higher temperatures tend to lower the process because of the mitigating action of the vegetation. Even under a significantly wetter climate, warmer air temperatures can limit soil erosion across areas with permanent vegetation cover by enhancing primary productivity and in turn improving leaf interception, soil infiltration-capacity, and the erosive resistance of soil. Consequently, under a global balance and for specific land uses, the increase in air temperature associated with climate change can modify the rainfall thresholds required to generate soil loss, and rates of soil erosion could decline by up to about 30% from 2070-2099. We deduce that enhanced primary productivity due to climate change can introduce a negative-feedback mechanism limiting soil loss by surface runoff as vegetation-induced impacts on soil hydrology and erodibility offset the effects of increased precipitation. The expansion of permanent vegetation cover could provide an adaptation strategy to reduce climate-driven soil loss.
... The longer-term research after the application of biochar was reported by Liu [28], after 18 months, compared with the initial stage of application, biochar delayed the time of rainfall runoff, reduced soil loss, and had the trend of reducing water and sediment. In strong climate change, the process of soil erosion may be intensified [29,30]. The report points out that in high-latitude and high-altitude areas, due to the phase change of water during freezing and thawing, soil particles are mechanically damaged [31][32][33], thus weakening the anti-erosion ability of runoff [34][35][36][37]. ...
Article
Full-text available
This research explored the effects of biochar on slope runoff and sediment transport processes and the hydrodynamic mechanism of rill erosion under the seasonal freeze–thaw climate in the black soil area of Northeast China. The four slopes of 1.8, 3.6, 5.4 and 7.2° were set, corn straw biochar was used, and three biochar contents of 0 kg m−2 (B0 treatment), 6 kg m−2 (B6 treatment) and 12 kg m−2 (B12 treatment) were applied. The experimental plot was placed outdoors to simulate the freeze–thaw cycle of sloping farmland under natural conditions. Three artificial simulated rainfall tests were carried out before the end of seasonal freeze–thaw cycles and spring sowing date (May) in 2018 and 2019. The sediment transport process of runoff and the variation of hydrodynamic parameters in rills were analyzed under one and two seasons of freezing and thawing in natural outdoor conditions. The results show that biochar has a positive effect on reducing rainfall runoff and soil loss after one year and two years of seasonal freezing and thawing. The effect of biochar on the sediment concentration of slope runoff increased with increasing application time; in the second year, the B6 and B12 treatments reduced the sediment concentration by 5.5–14.8% and 3.3–13.6%, respectively, compared with the values of the first year. The Reynolds number (Re) in the rill flow after the B6 and B12 treatments decreased with increasing duration, which effectively reduced the turbulence degree of the flow on the rill of the slope. With the increase in duration, the rill critical erosion power increased; in 2018 and 2019, the critical shear force, critical runoff power and critical unit runoff power were 0.403 Pa, 0.098 m s−1, and 0.002 N m−1 and 0.497 Pa, 0.124 m s−1, and 0.003 N m−1, respectively. This result indicates that increasing the duration and number of seasonal freeze–thaws can promote the development of biochar control of the runoff and sediment processes on slope and rill development.
... In Ethiopia today, soil erosion is the serious problem that arises because of land use changes. Overgrazing, improper management and expansion of settlements accelerate land loss, reduce agricultural production and increase sedimentation in the next catchment areas [1][2][3][4][5]. Since farmers are more dependent on rainfed farming practices, grazing and exercise in steep slopes, scarce of natural resources affect the population [6][7][8][9][10][11]. ...
Article
Full-text available
Soil erosion considered as one of the most important obstacles in the way of sustainable development of agriculture and natural resources. In Ethiopia, soil erosion is a serious problem. The studies on erosion risk in the watershed show a trend towards increasing land use, accelerating erosion in the study area. The influencing factor for the give watershed are the land use, the elevation, the slope, TWI, SPI, and soil. This study focus to determine and mapping the hotspot areas to erosion of rib watershed with an area of 1174.7 km 2. The sensitivity area for erosion was done by a multi-criteria decision evaluation method with parameters of influencing factors. The analysis of the maps using GIS analysis tools for different criteria which shows that the findings vary from one criterion to another. Considering all criteria, the finally obtained map shows that the areas with a high, moderate, low and very low vulnerability to erosion are 1.13%, 8.11%, 88.34% and 2.42% respectively in the given watershed. Overall, the soil erosion changes analysis and mapping as well as its distribution is effective and important for identifying natural resource prone areas. Therefore, the local experts and administrative bodies uses this information to prepare plan for those priority areas to conserve and monitor the degraded resources.
... 76 In turn, future climate change is expected to aff ect the extent, frequency, and magnitude of soil erosion, mostly because of changes in rainfall and temperature driven changes in plant biomass. 77 ...
... They are nature dependent or intrinsic to the landscape and independent from anthropogenic interventions (Nyakatawa et al., 2001). Changes in mean annual R-factor occur in the long-term from climate change-induced modifications in rainfall amount or the number and intensity of heavy rainfall events (Mullan, 2013). For the K-factor, the grain size distribution is usually stable over time. ...
Article
The cover-management factor (C-factor) of the Universal Soil Loss Equation (USLE) is the most important factor for estimating the effects of farming practices or agricultural policy measures on soil loss rates. This study, conducted in Switzerland from 1987 to 2017, assessed the impact of mitigation measures on arable land by comparing modelled C-factor values and measured soil losses. C-factor values were calculated in detail for 203 fields for five different periods (1987–89, 1997–99, 1997–2006, 2003–09, 2010–14) using a C-factor tool adapted to Swiss conditions. The C-factor values were compared with the measured soil loss rates of the same fields from the three periods 1987–89, 1997/98–2006/07, and 2007/08–2016/17. Given various action programmes, the share of conservation tillage practices increased from 4% in 1997/98 to 85% in 2014/15. The mean annual soil loss was 0.71 t ha–1 yr–1 (1987–89) and decreased by over two-thirds from 0.74 t ha–1 yr–1 (1997/98–2006/07) to 0.20 t ha–1 yr–1 (2007/08–2016/17), while the mean C-factor values were 0.136 in 1987–89 and decreased by almost half from 0.094 (1997–99) to 0.050 (2010–14). This study demonstrates that, with an in-depth calculation of C-factor values over different periods, changes amounting to soil loss resulting from the implementation of mitigation measures can be satisfactorily reproduced for a region.
... The on-farm declining of yield caused by the losses in land fertility is due to the degradation of land bearing low fertility (Eswaran et al. 2001;Mullan 2013). Low fertility on pot and field scale can reduce the production of agricultural crops between 30% and 90%, respectively (Mbagwu et al. 1984;Lal 1995). ...
Chapter
The industrial revolution has put the soil environment under pollution, pouring a variety of toxic substances into it. These polluting substances include organic and inorganic compounds that pose health risks to human beings via food chain. At present, emphasis has been given to those organic pollutants that sometimes have persistence and reside in soil for a very long time. Major sources of organic pollutants are the agricultural inputs, industrial effluents, fossil fuel burning, and sewage wastes. Several classes of harmful organic pollutants include persistent organic pollutants (POPs), phenols, hexachlorocyclohexanes (HCHs), polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and dichlorodiphenyltrichloroethanes (DDTs). Ultimate sink of all these contaminants is water bodies and soil on which growing plants take up a significant portion of these contaminants, but their intratissue fate varies among species. Phytoremediation of the soils contaminated with these organic pollutants is an economical, environment friendly, and efficient technique. Brassica species being famous for their vigorous growth and hyperaccumulator nature have become a subject of extensive investigations regarding their role in accumulation and degradation of pollutants from soil and water bodies. Brassica species can maintain a good and healthy growth that makes tissue dilution of uptaken contaminants and degradation of these intracellular invasive species via modulating cellular physiology and enzymatic machinery. Brassica vigorous roots provide active sites for static adsorption of contaminants from soil and water bodies and release exudates that facilitate growth of contaminant-degrading rhizobacteria. Bacterial brassica partnership has an incremental impact on degradation of organic pollutants so does application of immobilizing organic and inorganic amendments. Once uptaken, these contaminants are converted into sulfur-containing compounds inside Brassica body that make dry tissue of Brassica species an excellent fuel leading their use for energy generation under biofumigation process. This chapter is an effort to give a comprehensive review on the fate of organic pollutants in the environment and the role of Brassica species in environmental cleansing via phytoremediation.
... As temperature increases, evapotranspiration increases and soil moisture decreases, thereby increasing the soil's water infiltration capacity and reducing runoff and soil erosion (Xu 2003). Moreover, CO 2 -driven changes in plant biomass production and organic matter decomposition rates may decrease soil erosion by increasing vegetation cover (Mullan 2013). In contrast, plant stress created by high temperatures may increase erosion rates by increasing evaporation, reducing the availability of soil water, and thereby decreasing plant growth (Pruski and Nearing 2002;Li and Fang 2016). ...
Article
Full-text available
Soil erosion caused by climate and land-use changes is one of the biggest environmental challenges in highland Ethiopia. The aim of this study was to assess the future soil erosion risks and evaluate the potential conservation measures in the Rib watershed, northwestern highland Ethiopia. We used the HadGEM2-ES model with a moderate greenhouse gas (GHG) concentration scenario (RCP4.5) to project the future climate. The future land-use patterns were predicted using the CA-Markov model. We integrated the RUSLE model with GIS to estimate the spatial distribution of soil loss and identify erosion risk areas. We found that the Rib watershed is highly vulnerable to future climate and land-use changes, leading to a high soil erosion risk. Despite slight growth of forest cover during the study period, the total soil loss for the watershed was estimated to be 7.93 × 106 t year−1 in 2017 and was predicted to increase to 9.75 × 106 t year−1 in 2050, an increase of about 23%. The increase in forest cover was due to the expansion of the area of eucalyptus plantations which are more prone to erosion. Moreover, field survey showed that the residual native forests are sparsely vegetated and mostly used for cattle grazing, increasing the erosion risk even more. In contrast, the combined use of afforestation with native trees and physical soil conservation measures in the upper areas of the catchment could decrease soil loss by 62%. Our results stress the importance of combining soil conservation measures, including converting eucalyptus plantations to native forests, to mitigate the effects of future climate change and increased agricultural production on soil erosion.
... Among existing soil erosion models, the physical process-based Water Erosion Prediction Project (WEPP) model is a popular option for evaluating the climatic effect of site-specific soil loss. It has been widely used to assess climatic impacts on soil loss, runoff, and crop production across the globe (Baffaut et al., 1996;Favis-Mortlock and Guerra, 1999;Garbrecht and Zhang, 2015;Mullan, 2013;Nearing et al., 2005;O'Neal et al., 2005;Zhang, 2012;Zhang and Nearing, 2005;Zhang et al., 2004b). However, most studies have only applied a few GCMs/RCMs to hydrologic and crop growth models to examine the impact on runoff, soil loss, and crop yield to future agricultural production. ...
Article
To develop effective conservation practices to respond to future climatic challenges, the effects of various cropping and tillage systems on surface runoff and soil loss need to be evaluated under extensive geographical conditions. This study used a total of 100 climate scenarios generated from 25 downscaled General Circulation Model (GCM) projections under two Representative Concentration Pathways (RCP4.5 and 8.5) during 2021–2050 and 2051–2080. Those 100 future scenarios were combined with 29 cropping and tillage systems to simulate surface runoff, soil erosion, and crop production response to climate change using the Water Erosion Prediction Project (WEPP) model. The results showed that average annual precipitation in central Oklahoma was projected to significantly decrease by 4–6% (p < 0.05) during the two time periods for both RCP scenarios. Mean annual temperatures were projected to significantly increase (p < 0.01) by 1.74 ℃ for RCP4.5 and 1.99 ℃ for RCP8.5 during 2021–2050, and 2.65 ℃ for RCP4.5 and 3.90 ℃ for RCP8.5 during 2051–2080. Annual runoff and soil loss averaged over the two RCPs and all crop types was projected to decrease by approximately 1% and 3%, respectively. Except for cotton, crop yields were predicted to decrease by 10.3%–18.3% during 2021–2080. Simulated annual runoff depth and soil loss separately followed the order of reduced tillage (RT) > delayed tillage (DT) > no-till (NT) > conventional tillage (CT) and RT > CT > DT > NT under future climate scenarios, respectively. If economically feasible, no-till and the crop-alfalfa rotation were the most effective soil conservation method on farmlands to combat projected future erosion due to changing precipitation and temperatures.
... Soil texture, depth, structure, organic matter content and the presence of a surface crust strongly determine soil infiltration and soil water storage capacity, and therefore the response of soil to precipitation events. However, if future erosion rates exceed present rates, off-site impacts may become more widespread and more intense than today (Mullan, 2013). As an example, the costs of a landslide event in Italy exceeded 33 million Euro (Hervas, 2003). ...
Technical Report
Full-text available
This report presents evidence of the societal challenges of transboundary impacts, the drivers, and consequences of soil degradation, as well as data and knowledge gaps. The message conveyed by the report is that there is clear evidence of transboundary impacts and drivers of soil degradation and that it has physical, ecological, economic and social causes. Soil degradation does not stop at borders.
... Otepľovanie klímy ovplyvňuje eróziu pôdy prostredníctvom zmien vo vegetačnom kryte a pôdnej vlhkosti (NEARING ET AL. 2004). Kombinácia zmien v zrážkach a zmene teplôt bude pravdepodobne sprevádzaná zmenami v pestovaní poľnohospodárskych plodín a ďalších agrotechnických postupov (MULLAN, 2013). Zmena klímy, ako už bolo uvedené, môže prispieť k zintenzívneniu eróznych procesov v oblastiach náchylných na vodnú a veternú eróziu. ...
... Neste viés, o índice de erosividade pode ser definido como uma função da frequência e da intensidade das chuvas, ambas influenciadas pelas mudanças climáticas (SEGURA et al., 2014). Nesse sentido, várias pesquisas calcularam o fator R e o relacionaram com mudanças climáticas: em escala global (WILLIAMS et al., 1996;NEARING, 2002;; para a Ásia (ZHANG et al., 2007;MA et al., 2010;ZHANG et al., 2010;SHIONO et al., 2013;PLANGOEN;BABEL, 2014;ZHANG et al., 2015;MONDAL et al., 2016;ZHU et al., 2019a); para a Europa (KLIK e EITZINGER, 2010;MULLAN, 2013;PANAGOS et al., 2017); para os Estados Unidos da América (NEARING, 2001;NEARING et al., 2005;ZHANG;BIASUTTI;SEAGER, 2015;HOOMEHR et al., 2016); para a Austrália (ZHU et al., 2019b); e, finalmente, para o Brasil (FAVIS-MORTLOCK;GUERRA, 1999;ALMAGRO et al., 2017;ANACHE et al., 2018;COLMAN et al., 2019). ...
Article
Full-text available
A erosividade da chuva é um dos principais fatores desencadeadores da erosão. Diante disso, os objetivos desta pesquisa são calcular, espacializar, estimar o tempo de retorno e encontrar tendências de aumento da erosividade anual e mensal na bacia hidrográfica do rio Santa Maria (RS) - BHRSM. A análise da erosividade foi realizada com base em dados pluviométricos diários, no período de 1986-2019, de sete estações meteorológicas (EM). Foi utilizada uma equação de regressão de Bazzano et al. (2007) para Quaraí (RS) para transformação da precipitação diária em escalas de segundos para cálculo da erosividade. A espacialização dos dados foi realizada pelo método de interpolação IDW do SIG QGIS 3.4. A erosividade média anual da BHRSM (fator R da EUPS) é de ~11.979 MJ.mm.ha-1.h-1.ano-1, sendo classificada como “muito forte” e se concentrando no período de outubro-maio (73%), justamente o período em que acontece o plantio, desenvolvimento e colheita das culturas temporárias. O mês de abril é o de maior potencial erosivo, com 1.650 MJ.mm.ha-1.h- 1.mês- 1. A maior taxa de erosividade anual, de 24.868,89 MJ.mm.ha-1.h-1.ano-1, apresentou tempo de retorno estimado de 35 anos, com probabilidade de ocorrência de 2,85%. Os valores de tendências de erosividade mais elevados foram encontrados entre os anos de 2010 e 2019 em 6 das 7 EM. Por fim, salienta-se que a erosão linear com formação de voçorocas já foi identificada por vários autores na BHRSM, principalmente em sua porção norte, e a estação com maiores valores erosivos se localiza justamente nessa área.
... Changes in land use due to climate change, such as the adoption of new crops (e.g. warm-tolerant crops), could also increase soil erosion on erosion-prone soils (Mullan 2013), and increased summer drying of soils will likely increase dust production from cultivated soil, thereby causing soil loss and a threat to human health. More intense and recurring droughts will cause shrinking and swelling in clay-rich soils, causing damage to buildings and infrastructure on clay soil. ...
... change, land use and land cover change (LUCC), and other anthropogenic activities are commonly considered potential agents that drive variation in soil erosion rates (Nearing et al., 2004;. The impacts of climate change (e.g., Nearing et al., 2004;Zhang and Nearing, 2005;Mullan, 2013;Palazon and Navas, 2016) and of LUCC (e.g., Bochet et al., 2006;Korkanç et al., 2018;Nampak et al., 2018;Perović et al., 2018) on erosion have been studied in recent years. As the two agents usually exert their influence on soil erosion simultaneously, their relative contributions have also been increasingly investigated (e.g., Bellin et al., 2013;Sun et al., 2020;. ...
Article
Full-text available
Climate change and agricultural intensification are expected to increase soil erosion and sediment production from arable land in many regions. However, to date, most studies have been based on short-term monitoring and/or modeling, making it difficult to assess their reliability in terms of estimating long-term changes. We present the results of a unique data set consisting of measurements of sediment loads from a 60 ha catchment-the Hydrological Open Air Laboratory (HOAL)-in Petzenkirchen, Austria, which was observed periodically over a time period spanning 72 years. Specifically, we compare Period I (1946-1954) and Period II (2002-2017) by fitting sediment rating curves (SRCs) for the growth and dormant seasons for each of the periods. The results suggest a significant increase in sediment loads from Period I to Period II, with an average of 5.8 ± 3.8 to 60.0 ± 140.0 t yr −1. The sediment flux changed mainly due to a shift in the SRCs, given that the mean daily discharge significantly decreased from 5.0 ± 14.5 L s −1 for Period I to 3.8 ± 6.6 L s −1 for Period II. The slopes of the SRCs for the growing season and the dormant season of Period I were 0.3 and 0.8, respectively, whereas they were 1.6 and 1.7 for Period II, respectively. Climate change, considered in terms of rainfall erosivity, was not responsible for this shift, because erosivity decreased by 30.4 % from the dormant season of Period I to that of Period II, and no significant difference was found between the growing seasons of periods I and II. However, the change in sediment flux can be explained by land use and land cover change (LUCC) and the change in land structure (i.e., the organization of land parcels). Under low-and median-streamflow conditions, the land structure in Period II (i.e., the parcel effect) had no apparent influence on sediment yield. With increasing streamflow, it became more important in controlling sediment yield, as a result of an enhanced sediment connec-tivity in the landscape, leading to a dominant role under high-flow conditions. The increase in crops that make the landscape prone to erosion and the change in land uses between periods I and II led to an increase in sediment flux, although its relevance was surpassed by the effect of parcel structure change under high-flow conditions. We conclude that LUCC and land structure change should be accounted for when assessing sediment flux changes. Especially under high-flow conditions, land structure change substantially altered sediment fluxes, which is most relevant for long-term sediment loads and land degradation. Therefore, increased attention to improving land structure is needed in climate adaptation and agricultural catchment management.
... It requires a combination of statistical links and theoretically informed causation, preferably integrated into a model. Some modelling studies have combined several stressors with geomorphologically explicit mechanismsusing the Water Erosion Prediction Project (WEPP) model -and realistic land-use scenarios, and found severe risks of increasing erosion from climate change (Mullan et al. 2012;Mullan 2013). Other studies have included various management options, such as changing planting and harvest dates (Zhang and Nearing 2005;Parajuli et al. 2016;Routschek et al. 2014;Nunes and Nearing 2011), type of cultivars (Garbrecht and Zhang 2015), and price of crops (Garbrecht et al. 2007;O'Neal et al. 2005) to investigate the complexity of how new climate regimes may alter soil erosion rates. ...
Technical Report
Full-text available
This chapter examines the scientific understanding of how climate change impacts land degradation, and vice versa, with a focus on non-drylands. Land degradation of drylands is covered in Chapter 3. After providing definitions and the context (Section 4.1) we proceed with a theoretical explanation of the different processes of land degradation and how they are related to climate and to climate change, where possible (Section 4.2). Two sections are devoted to a systematic assessment of the scientific literature on status and trend of land degradation (Section 4.3) and projections of land degradation (Section 4.4). Then follows a section where we assess the impacts of climate change mitigation options, bioenergy and land-based technologies for carbon dioxide removal (CDR), on land degradation (Section 4.5). The ways in which land degradation can impact on climate and climate change are assessed in Section 4.6. The impacts of climate-related land degradation on human and natural systems are assessed in Section 4.7. The remainder of the chapter assesses land degradation mitigation options based on the concept of sustainable land management: avoid, reduce and reverse land degradation (Section 4.8), followed by a presentation of eight illustrative case studies of land degradation and remedies (Section 4.9). The chapter ends with a discussion of the most critical knowledge gaps and areas for further research (Section 4.10).
... In addition, the topography of the black soil area is characterized by "overflowing rivers and hills," and is vulnerable to soil erosion by runoff in summer, wind erosion in spring and autumn, and freeze-thaw erosion in winter (Fan, 2013;. In particular, regionally irregular precipitation is projected to occur under the influence of global climate change (Qi & Cai, 2018) and will likely to lead to increased soil erosion (Mullan, 2013;Qadir et al., 2013). Erosion from water will likely occur because of the sloping nature of the cultivated land in the black soil area although the slopes are generally less than 8 degrees. ...
Chapter
Full-text available
Maize is an important food crops across the world and provides at least 30% of the food calories to more than 4.5 billion people in 94 developing countries. Maize is also a basic constituent in animal feed and is used broadly in industrial products like biofuels production. Due to increasing demand and production, global maize supplies and prices have been badly affected. Further, climatic change and the consequences of changes raise the abiotic and biotic stresses. Climate change challenges reduced growth and yield which leads hunger and food insecurity for millions of poor consumers. In the context of climate change, this chapter summarizes the challenges faced by maize and how these challenges can cope to meet future maize demand. Consideration needs to be directed at the production of high yielding, stress-tolerant, and widely-adapted maize varieties through conventional and molecular breeding approaches. For long-term approaches, large public and private sector investment and sustained political commitment and policy support for new technology are needed to overcome hunger, raise the incomes of smallholder farmers and meet the challenges of growing demand for maize at the global level.
... In addition, the topography of the black soil area is characterized by "overflowing rivers and hills," and is vulnerable to soil erosion by runoff in summer, wind erosion in spring and autumn, and freeze-thaw erosion in winter (Fan, 2013;. In particular, regionally irregular precipitation is projected to occur under the influence of global climate change (Qi & Cai, 2018) and will likely to lead to increased soil erosion (Mullan, 2013;Qadir et al., 2013). Erosion from water will likely occur because of the sloping nature of the cultivated land in the black soil area although the slopes are generally less than 8 degrees. ...
Chapter
The concentration of atmospheric carbon dioxide (CO2) has almost doubled since the preindustrial era due to global climate change and is expected to further increase if the current emission rates are not controlled. The impacts of elevated CO2 (e[CO2]) on growth, development, and yield of plant species, particularly crops, are very important concerns for the scientist. This is due to dynamic implications on global agricultural production and food security in the climate change scenario. Crops respond to the e[CO2] by stimulating the photosynthetic rate. which boosts crop yield. Higher levels of atmospheric carbon act like a carbon fertilizer for the plants and results in an increase in plant growth and productivity. Cereal crops grow larger in size and exhibit faster growth rates under e[CO2], and biomass production becomes higher. Crops have evolved strategies to enhance their physiological performance by increasing water use efficiency and reducing the transpirational water loss as well as lowering stomatal conductance under e[CO2]. C3 plants exhibit considerably higher increases in yield due to e[CO2] ranging from 20% and 35% as compared to C4 crops with only 10% to 15%. e[CO2] influences the qualitative attributes of crops, including the concentration of nutrients, which are fundamental food quality attributes having diverse implications on agricultural production, market value of crops as well as impacts on human health. Sharp declines are projected in the protein content and free amino acid of cereals under e[CO2] conditions. Under realistic field conditions experiments, free-air CO2 enrichment technology revealed significant increases in the photosynthesis activity, leaf carbohydrates, starch and sugars whereas the concentration of nitrogen per unit leaf mass has been found to decrease. The relative yield responses of grain crops under e[CO2] might increase under limiting nutrient and water conditions due to physiological adaptations. The major C3 cereals, including wheat and rice, undergo major shifts in physiological responses and C:N metabolism in response to e[CO2], However, a reduction in nutritional quality under e[CO2] appears to be a major challenge.
... In addition, the topography of the black soil area is characterized by "overflowing rivers and hills," and is vulnerable to soil erosion by runoff in summer, wind erosion in spring and autumn, and freeze-thaw erosion in winter (Fan, 2013;. In particular, regionally irregular precipitation is projected to occur under the influence of global climate change (Qi & Cai, 2018) and will likely to lead to increased soil erosion (Mullan, 2013;Qadir et al., 2013). Erosion from water will likely occur because of the sloping nature of the cultivated land in the black soil area although the slopes are generally less than 8 degrees. ...
Chapter
Full-text available
Intensified drought stress threatens plant growth and productivity, while elevated CO2 (e[CO2]) alleviates the negative impact of drought stress on plants through alteration in water use and improvement in plant growth. In the terrestrial ecosystem, crops are particularly sensitive to drought and benefit from e[CO2]. To cope with the drier and CO2-enriched climate, plants have evolved various adaptive strategies. Water-dependent crops can benefit from e[CO2] but are species-dependent and depend on the intensities and durations of drought stress. In this chapter, we summarized drought impact on crops, crop performance under e[CO2], as well as their interactions in physiological, biochemical, and molecular levels.
Article
As one of the most intensively eroded regions worldwide, soil erosion assessment is currently gaining further momentum in the Loess Plateau (LP), China. However, there exist very few review studies that assess soil erosion in relation to land use and land cover (LULC), climate, and ecosystem services (ESs) at multiple temporal and spatial scales in the LP. Thus, this review provides a comprehensive review of the interactions among soil erosion assessment, climate change, LULC change, and ESs at different scales. We focused on the academic literature published in the English language and analyzed the coverage of soil erosion across 109 publications. Our results highlighted three aspects: (1) studies dealing with the effects of LULC change on soil erosion are abundant. A recent surge in research interest is to explore a threshold of vegetation cover to support a sustainable eco-hydrological environment in the LP. However, the impacts of multiple stressors on soil erosion have received limited attention. (2) The short-term soil erosion assessment dominated the published studies. Cross-spatial-scale and long-term erosion assessments have received little attention. (3) 43% of reviewed papers used a field measurement method to assess soil erosion with the validation of measurement methods. 41% of reviewed papers used empirical models to assess soil erosion, but the modeling validation remains an unsolved problem. Then, three recommendations are listed as follows: (1) the combined impacts of LULC and climate change on soil erosion need to be further examined. (2) Long-term and cross-spatial-scale soil erosion assessments need to be established. (3) Soil erosion modeling accuracy on a large scale needs to be developed.
Article
Full-text available
Soil erosion has a severe impact on habitat and productivity. It is considered to be a major environmental threat prevalent in ecosystems. However, few researchers have studied the spatial distribution of soil erosion intensity among different geographic environmental factors. The Qin River Basin is a geographical unit consisting of mountains, hills, and plains with significant regional characteristics, and it has a basin area of 14,810.91 km ² . This study uses the Geographical Information Systems, Revised Universal Soil Loss Equation model to analyze the spatiotemporal changes in the soil-erosion intensity in the Qin River Basin from 1990 to 2018. Different environmental factors of land use, slope and altitude on erosion intensities of 19 secondary land types were analyzed. It can better reflect the soil erosion under different environmental factors and different land use types. Results show that the soil erosion modulus of Qin River Basin were 10.25 t hm ⁻² a ⁻¹ , and it belong to slight erosion from 1990 to 2018. Soil erosion intensity is greater in grassland and woodland than in cropland. The strongest soil erosion occurred in the sparse forestland, and the lowest was in beach land. Soil erosion was the highest for a slope of 15~25° and an altitude of 1200~1500 m. Rainfall and slope are important factors lead to soil erosion, indicating weak water and soil conservation implemented in these areas. Therefore, priority should be given to these geomorphic units to formulate and implement soil-erosion control and ecological restoration policies in the Qin River Basin. This study provides a good reference for preventing and controlling soil erosion in river basins.
Research
Full-text available
Erosion processes and soil degradation are objects of study for many studies in the field of geomorphology. The complexity of soil properties and the different factors that interfere with erosion are responsible for generating different situations under the landscape. In this regard, the present study aimed to make a diagnosis of a gully on a road (BR-494), identified through remote sensing, using the Google Earth Pro software. Understanding the landscape dynamics and the processes that occur arouses the interest of researchers , but also those responsible for spatial planning. Since the development of GIS tools took place with technological advances, during the twentieth century. Like the debates about the conservation of the environment, remote sensing is now essential for the application of space-time analysis under a terrestrial surface. Although the use of Google Earth Pro is questioned, as to the quality of its data collection, it is a tool that, when reconciled with laboratory analysis, and the field trip becomes an important instrument for planning and carrying out work in order to identify and monitor areas degraded by gully erosion. From the images obtained, it is possible to verify the possible finding of an active erosion process, with periods of regression and longitudinal growth of the feature between 2007 and 2019. Keywords: Soil erosion; Geomorphology; Remote sensing; Landscape
Article
Full-text available
There is the need of a better knowledge of rill detachment rates of forest soils with different morphological characteristics and management. This study has evaluated the rill detachment capacity and the main soil properties in three areas (upper, middle and lower slope) of forest and deforested hillslopes exposed to north and south in Northern Iran. The large difference (about 70%) in rill detachment capacity between forest and deforested hillslopes was associated due to the higher organic matter content, and, as a consequence, higher aggregate stability, porosity, root weight density, microbial respiration and available water of forest areas. In the deforested hillslopes exposed to south soil erodibility was higher by 12% compared to north, but the differences in the monitored soil properties were less noticeable. Conversely, the rill detachment capacity was not significantly changed among the different soil positions investigated in this study. Simple but accurate models to predict the detachment capacity, rill erodibility and critical shear stress of soils from indicators of soil quality or unit stream power using regression equations are suggested. Overall, the results can support land planners in prioritise the actions for soil conservation as well as in the extensive application of erosion prediction models.
Article
Full-text available
Rill detachment capacity is a key parameter in concentrated flow erosion. Rill erosion generally turns into gully erosion with severe environmental impacts. Changes in land use and human activities can have heavy effects in rill formation, particularly in forests subject to deforestation; soil morphology plays a significant role in these effects. However, literature reports few studies about rill detachment rates and their implications on soil quality in forest and deforested soils with different morphological characteristics. To fill these gaps, this study has evaluated the rill detachment capacity (Dc) and the main soil quality indicators in three areas (upper, middle and lower slope) of forest and deforested (for 10 years) hillslopes exposed to the north and south in Northern Iran. The variations of Dc have been measured on soil samples under laboratory conditions through a flume experiment at three slope gradients (12 to 19%) and five flow rates (0.22 to 0.67 L m−1 s−1) with four replications. The large and significant (p < 0.05) difference (about 70%) detected for Dc between forest and deforested hillslopes was associated to the higher organic matter content of forest areas; as a consequence, these areas also showed higher aggregate stability, porosity, root weight density, microbial respiration and available water. In the deforested hillslopes exposed to the south, the soil erodibility was higher by 12% compared to those exposed to the north. The differences in the monitored soil quality indicators were instead less noticeable and not always significant (p < 0.05). Conversely, Dc did not significantly change (p < 0.05) among the upper, middle and lower hillslope areas investigated in this study. Simple but accurate models to predict the rill detachment capacity, erodibility and critical shear stress of soils from indicators of soil quality or the unit stream power using regression equations are suggested. Overall, the results can support land planners in prioritizing the actions for soil conservation in deforested hillslopes exposed to the south as well as in the extensive application of the proposed equations in erosion prediction models.
Article
The effects of climate change on water resources could be numerous and widespread, affecting water quality and water security across the globe. Variations in rainfall erosivity and temporal patterns, along with changes in biomass and land use, are some of the impacts climate change is projected to have on soil erosion. Sedimentation of watercourses and reservoirs, especially in water-stressed regions such as sub-Saharan Africa, may hamper climate change resilience. Modelling sediment yield under various climate change scenarios is vital to develop mitigation strategies which offset the negative effects of erosion and ensure infrastructure remains sustainable under future climate change. This study investigated the relative change in sediment yield with projected climate change using the Soil and Water Assessment Tool (SWAT) for a rural catchment in South Africa for the period 2015–2100. Data from six downscaled Coupled Global Climate Models (CGCM) were divided into three shorter time periods, namely, 2015–2034, 2045–2064 and 2081–2100. Results were then compared with a control scenario using observed data for the period 2002–2017. The results show that, if left unmanaged, climate change will likely lead to greater sediment yield, of up to 10% more per annum. Peak sediment yield will also increase almost three-fold throughout the century. The study shows that projected climate change will have multiple negative effects on soil erosion and emphasised the need for changes in climate to be considered when embarking on water resource developments.
Book
Soils provide the foundation for food production, soil water and nutrient cycling, and soil biological activities. With land use and land cover changes over the last century, soil fertility depletion, greenhouse gas emissions, irrigational water scarcity, and water pollution have threatened agricultural productivity and sustainability. An improved understanding of biochemical pathways of soil organic matter and nutrient cycling, and microbial communities involved in regulating soil health and soil processes associated with water flow and retention in soil profile helps design better agricultural systems and ultimately support plant growth and productivity. This book, Agroecological Approaches in Soil and Water Management, presents a collection of original research and review papers studying physical, chemical, and biological processes in soils and discusses multiple ecosystem services, including carbon sequestration, nutrients and water cycling, greenhouse gas emissions, and agro-environmental sustainability. The 15 chapters in this book cover various topics related to soil organic matter and nutrient cycling, soil water dynamics, and related hydrological processes across multiple soils, climate, and management. Several chapters highlight the impacts of land use, landscape position, and land-cover change on soil health and plant productivity. It also has chapters on greenhouse gas emissions as affected by agricultural management, and the roles of soil amendments like biochar and micronutrients. Novel water management strategies, including the use of coalbed methane co-produced water, biodegradable hydrogels, and livestock-integrated cropping to improve soil health are also discussed. The book further incorporates modeling studies on yield and greenhouse gas emissions and presents a review of sustainable agricultural and water management practices.
Chapter
Egypt is divided into three rainfall belts some regions are subjected to both soil erosion types and others are subjected to only wind erosion. The hazards of soil erosion take a variety of forms. In the Northwestern Coast Region (NWCR), few effective events are characterized by high rainfall intensity causing excessive runoff and soil loss. The annual runoff and soil loss were related to the number of them. Runoff also occurred when individual rainfall storm exceeds 10 mm/h. There are different indicators for rainfall erosivity differed in their significance. Concerning soil erodibility indicator for water erosion, there are different classes for it depend on the region. The power function is the best fitted relationship between soil erodibility indicator and estimated soil loss by USLE model. In NWCR, measured soil loss varied according to slope percent and increased with increasing the slope steepness, at the same rainfall erosivity. The enrichment ratios for some nutrients and clay fraction and organic matter were greater than 1. USLE model is the best for the assessment of annual soil loss and used as indicator of soil erosion by water under NWCR. Both climatic factor and soil erodibility indicated that about 80% of the studied areas suffer from wind erosion. Estimated soil loss characterized to three classes low, moderate and severe. These variations are dependent upon the land use. RWEQ could be used to estimate wind erosion rate under NWCZ conditions. Laboratory studies using Rainfall simulator and wind tunnel were used to study some parameters such as slope percent and threshold wind velocity affecting on water and wind erosion respectively. The strategies for soil erosion control mainly depend on different applications which consider some of the principles of sustainable soil management. Such as tillage to a depth of 30 cm with broadcast planting and perpendicular tillage across the slope was efficient for reducing the amount of soil loss. Combined application of organic matter with perpendicular tillage increased the reduction rate of soil loss by different percentage according to rate of organic manure. In addition, using contour tillage for consolidated soil reduced soil loss as a result of water erosion by 73.7, and 51.7%, as compared to the bare soil, and tillage of consolidated soil in up and down slopes, and consequently reduces its carrying capacity. The combination of two or three management measures for controlling soil erosion decreased the magnitude of soil loss likewise the yield of crops increased. From the economical point of view these measures could be used.
Article
Full-text available
در بسیاری از نقاط دنیا در آینده شدت و فراوانی بارش¬های سیل¬آسا در اثر تغییر اقلیم افزایش خواهد یافت. لذا لازم است چنین مطالعاتی بر اساس سناریوهای تغییر اقلیم بازنگری شوند. از ابزار¬های¬ کارآمد در چنین مطالعاتی، مدل¬های مولد داده¬های هواشناسی از جمله LARS-WG است. با آنکه GCMها تغییرات ویژگی¬¬های مختلف بارش را برای آینده پیش¬یابی می¬¬کنند، معمولاً در کاهش¬مقیاس توسط LARS-WG تنها تغییرات میانگین¬ها¬ی ماهانه اعمال می¬شود؛ و از تغییرات سایر مشخصات بارش چشم-پوشی می¬شود. در این مقاله، ضمن ارزیابی اثر تغییر اقلیم بر بارش¬های سیل¬آسای گرگان و خرم¬آباد، نتایج روشی که تغییرات مشخصات مختلف بارش را در کاهش¬مقیاس اعمال می¬کند (روش کامل¬تر) با روش متداولی که تنها تغییرات میانگین¬ها را اعمال می¬کند (روش ساده¬تر) مقایسه شده است. برای اقلیم آینده از سناریوهای بارش مدل CanESM2 تحت سناریوهای انتشار RCP2.6، RCP4.5 و RCP8.5 در دوره 2065-2036 استفاده شد. نتایج نشان داد که برای ارزیابی اثر تغییر اقلیم بر بارش¬های سیل¬آسا، علاوه بر تغییرات میانگین¬ها، لازم است تغییرات سایر آماره¬ها نیز اعمال شود. زیرا تفاوت نتایج دو روش قابل توجه است. مثلا در گرگان برای سناریوهای انتشار مختلف، بارش¬های روزانه حداکثر سالانه¬ی با دوره بازگشت 15 سال در آینده نسبت به دوره تاریخی، طبق روش کامل¬تر بین 16 تا 21 درصد، اما طبق روش ساده¬تر، بین 37 تا 49 درصد افزایش می¬یابند. طیق روش کامل¬تر، شدت بارش¬های سیل¬آسای هر دو ایستگاه در آینده افزایش خواهد یافت. این افزایش برای دوره بازگشت 2 سال بین 23% تا 30% و برای دوره بازگشت 30 سال بین 25% تا 29% خواهد بود. The frequency and intensity of extreme rainfalls will increase over many areas of the globe due to climate change. So, it is required to revise result of such studies based on the climate change scenarios. One of the most effective tools in such studies is Weather Generators, including LARS-WG. While GCMs predict future changes in the various characteristics of precipitation, usually in downscaling using LARS-WG, just changes of monthly averages are considered. In this paper, the future climate change impact on extreme precipitation in Gorgan and Khoramabad stations are assessed; while, the results of two methods of applying just change in averages (simple method) or applying changes in various characteristics of precipitation (complete method) in downscaling are compared. For future, CanESM2 outputs under RCP2.6, RCP4.5, and RCP8.5 scenarios for 2036-2065 period were used. The results showed that for climate change impact assessment on extreme rainfalls, additional to change in averages, change in other precipitation characteristics should be considered. Because the results of the two methods are different. In Gorgan, for example, the annual maximum daily rainfall with a return period of 15 years in the future will increase by 16 to 21 percent according to the more complete method, but between 37 and 49 percent according to the simpler method. Based on the complete, Intensity of the extreme rainfalls at both stations will increase in the future. This increase will be between 23% and 30% for the 2-year return period and between 25% and 29% for the 30-year return period.
Chapter
Degradation of the land ecosystem is a major problem in India due to biotic and abiotic interferences. About 121 M ha land has been degraded and largely falls under rainfed regions. It has negative impacts on agricultural production and economy and the natural environment. In India, the per capita availability of both land and water is declining exponentially due to increasing population pressures. The arable land has dwindled from 0.48 ha in 1950 to 0.15 ha in 2000 and is likely to further reduce to 0.08 ha by 2020. The water availability declined from 1816 m³ in 2001 to 1511 m³ in 2011 against the world’s average of 7400 m³ and Asian countries’ average of 3240 m³. These issues and challenges need to be addressed by the adoption of smart, site-specific soil and water conservation practices. The field studies conducted in the semiarid agroecological region showed that the implementation of various conservation practices increased crop yield and biomass production, reduced runoff and soil loss, increased groundwater recharge, and improved socioeconomic conditions of the farmers. Therefore, the conservation practices tested in the semiarid region of India can be extended to other agroecological regions of the world for better management of degraded lands for reducing runoff and soil erosion for sustaining and stabilizing productivity of the food, fodder, and fuel.
Article
Soil erosion is one of the greatest risks worldwide for land degradation. Avoiding it is one of the greatest socio-environmental and economic challenges within sustainable development in connection with food production and maintenance of soil functions in the context of climate change. This study will allow us to answer how long-term occupation dynamics influenced by notable changes in the landscape have led to soil erosion through time. We used Geographical Information Systems to apply the Revised Universal Soil Loss Equation to assess soil erosion on prehispanic and present occupation scenarios that differ in climate and land use management in the Teotihuacan Valley, central Mexico. We analyzed how a heterogeneous landscape and its occupation dynamics over the last two millennia were affected by soil erosion in order to identify which biophysical and anthropogenic components affect soil loss. The settlements extended during Aztec periods over previously forested hillslopes which caused an increase in erosion rates. The greatest soil loss occurred during the humid Aztec period, followed by the Modern period. The differences between average erosion and potential erosion of these periods demonstrate greater effectiveness in controlling erosion during the Aztec period. The most relevant factors involved were land use and soil management, followed by climate and support practices. Our results indicate that in the face of climatic variations, soil management has a significant impact, even greater than rain erosivity. Our results suggest that pre-Hispanic cultures in the highlands of central Mexico may have caused soil erosion at least at rates similar to or even higher than those at present. The comparisons of the scenarios enable researchers and decision makers to identify high-risk areas and to implement sustainable measures against soil erosion.
Article
Due to the high rainfall erosivity and highly erodible soils, water erosion is severe in Brazil. Soil and ecosystem degradation occurs when erosion exceeds on- and off-site soil loss tolerances, with significant socioeconomic and environmental impacts. In the last 50 years, the Brazilian Cerrado had 53% of its original vegetation converted to agriculture and pastureland. Although erosion plot studies exist in the region, the data are fragmented and unexplored, hindering the development of soil conservation policies. The objective of the present research was to compile, systematize, and statistically analyze the existing erosion plot data in the Brazilian Cerrado, correlating the observed results with different environmental and management factors, and with the corresponding soil loss tolerances. Twenty runoff plot datasets of the Brazilian Cerrado, encompassing 5 states, 10 sites, 108 plots, and 360 plot·years were compiled and thoroughly analyzed. Mean annual rainfall, runoff, and soil loss were 1443.5 mm year−1, 83.1 mm year−1, and 8.9 Mg ha−1 year−1, respectively. After the data were normalized with respect to plot length, steepness, and climate, runoff and soil loss were found to be significantly higher in soils with impermeable horizons and in land uses without permanent soil cover (p < 0.05). Erosion under permanently covered plots was below the on- and off-site soil loss tolerances. A power equation provided the best fit between plot runoff and soil loss (R2 = 0.71; p < 0.05), indicating that runoff volume, easier to estimate, could be used as a proxy for upslope erosion. Although erosion plot data cannot be extrapolated to the whole landscape, the research results provide useful elements for the development of sound conservation policies in the Cerrado and in other similar savannas of the world.
Thesis
Full-text available
The distribution and expressive occurrence of surface erosive processes caused by hydrological dynamics in tropical semi-arid environments, may vary both spatially and temporally. This feature highlights a serious problem, especially in the development of agricultural practices, as these environments are naturally unstable, because of its natural elements (geology, geomorphology, soils, plant cover and climate) and usually have an unbalanced socioeconomic organization. There are many problems caused by the spread of erosion accelerated in these environments, such as: loss of natural soil fertility, siltation of water bodies, water supplies, decreased productivity of agricultural areas, accelerating the process of desertification, emission CO2 to atmosphere, impoverishment of rural communities, rural exodus, among other problems. Thus, the Brazilian semiarid region which is located in Paraiba (Cariri) includes unique features with regard to its physical environment (natural) and their socioeconomic organization. Therefore, the present study had as objectives: to analyze the hydro-erosive dynamics under different classes of soil (Regosol and Luvisol) and different types of use and management (palm culture and fallow system) in a semiarid zone; characterize and classify soils; evaluate runoff and erosion rates; analyze the selectivity of eroded materials; and understand the dynamics of water infiltration in soils. For this purpose, two trenches were opened for morphological description and collections of soil samples, and soon afterwards the material collected was sent to the laboratory for routine analysis (physical and chemical); 4 hydro-erosive plots were installed (GUERRA, 2005), in a proportion of 10 m2, with reservoirs in the gutters of all plots, to collect the material carried during the rainy events, in two different types of soils: Regosol and Luvisol (significant for the region studied), under different types of use and management (palm and fallow cultivation), to measure runoff and erosion rates; the sediments collected from the hydro-erosive plots were sent to the laboratory to understand the selectivity of the materials (amount of Carbon (C), Nitrogen (N) and textural class); ring infiltrometers were also positioned in the two soil types, in order to know the speed of water infiltration at different times of the year. The results reported in the portions positioned Regosol (PNRPal and PNRPou) generated more erosion than the portions on Luvisol (PLCPal and PLCPou), which in turn, gave greater values of runoff. Plots with the fallow system (PNRPou and PLCPou) were more efficient in containing hydro-erosive dynamics than plots with palm cultivation (PNRPal and PLCPal). It draws attention the plots on the Regosol, where the erosion measured in the PNRPal plot exceeded by 152 times, the erosion collected in the PNRPou plot, showing that a simple change in use and/or management can strongly unbalance natural systems. The highest runnof and erosion rates were analyzed on days with consecutive rains, exposing the importance of antecedent humidity in the occurrence of hydroerosive processes. Statistical correlations show that runoff has a good correlation with rainfall, whereas erosion is remarkably close to runoff. The analysis of the sediments allowed to identify that the plots with palm plantations (PNRPal and PLCPal) lost about 5,6 times of Carbon (C) and 7,8 times of Nitrogen (N), more than the plots in system fallow land (PNRPou and PLCPou), highlighting the PNRPal plot, which alone lost 139% more C and N than all other plots combined. Regarding the granulometry of the sediments, the strong correlation with the parent material is noteworthy, since the PNRPal plot has about 73,1% of coarse and fine sand (sand textural class), and the PLCPal and PLCPou plots, had more than 92% of silt and clay (textural class from clayey to very clayey), being only the PNRPou plot that did not allow the analysis of its granulometry due to insufficiency of collected material, showing its great efficiency in the control of the hydro-erosive dynamics. The most important variables in the variability of runoff and erosion data and in the selectivity of sediments (nutrients and textural class) were the different soil types (Regosol and Luvisol) associated with the different types of use and management (palm culture and system fallow). The infiltration tests show that the highest values of infiltration speed occur in the driest months (low soil moisture), then in the rainy months (high soil moisture). The tests carried out in the Regosol have a higher constancy in the basic infiltration speed (VIB) than the Luvisol, although the Luvisol at specific times of the year can overcome the infiltration rates of the Regosol. In general, the Regosol showed to be more sensitive to anthropic interferences than the Luvisol, in relation to the hydro-erosive dynamics and in the selectivity of the sediments. When it comes to the infiltration dynamics, Luvisol because it contains high clays activity (type 2:1) in its structure, undergoes more changes throughout the year than the Regosol, showing greater variability in the results. Therefore, it is suggested to expand the measurement of hydro-erosive processes in the Brazilian semiarid region, to improve understanding of the spatial and temporal variability of thesephenomena, such knowledge is essential not only for the progress of erosive studies in a semiarid environment, but also can serve to subsidize public policies that aim at the ordering and management of rural spaces. Key-words: Erosion, surface runoff, Semiarid, Regosol, Luvisol, types of use and management.
Chapter
Soil conservation programmes and policies are justified by evidence of soil degradation processes and their negative impacts on natural capital. The last national survey of the state of soil resources in England and Wales was carried out in the 1980s. Whilst smaller scale monitoring has been continued [e.g. National Soil Survey Resurvey (SSLRC 1996); Countryside Survey (Norton et al. 2012)], these surveys covered fewer sites and in the case of the Countryside Survey the only direct measure of soil degradation (as defined by the EU Thematic Strategy for Soil Protection) was change in soil carbon. This chapter presents the evidence on the extent and severity of the different processes of soil degradation, with emphasis on soil erosion by water. The economic, environmental and social impacts of these processes in England and Wales are also discussed.
Article
Soil erosion by water from arable land poses a serious threat to on-field agricultural productivity and the wider environment through off-site damage. Multiple studies show that climate change will worsen the impacts of soil erosion in various regions. However, these studies are limited by (1) the lack of any thorough evaluation process in applying climate scenarios to drive soil erosion models, and (2) the failure to consider the role of changing land use under future climate change, despite the evidence that it is more important than rainfall changes in driving increased erosion. Using the WEPP soil erosion model, these methodological gaps are addressed in this study for a small catchment in Belgium that is both heavily impacted by soil erosion and boasting an extensive array of mitigation measures. We develop a novel and comprehensive methodology to rigorously and efficiently select suitable climate models specifically for simulating soil erosion by water, and examine the impact of a range of environmentally and economically viable land use choices on soil erosion. The main findings reveal that our climate model selection methodology is successful in generating the widest range of likely future scenarios from a small number of models, compared with other selection methods. Our novel methodology reveals that the magnitude and frequency of soil erosion events will increase considerably under the mean of all scenarios between 2041 and 2100 with existing land management. Winter wheat represents the most economically and environmentally viable land use choice to effectively mitigate future soil erosion when compared to other land use alternatives under the full range of likely future climate scenarios. This research illuminates the importance of carefully tuned climate model selection and land use changes for modelling future soil erosion by water so the best- and worst-case scenarios can be adequately prepared for under a changing climate.
Chapter
Northeast black soil region in China is one of the four global black soil regions, and accounts for approximately 12% of the total black soil regions in the world. The unique climate conditions in Northeast China produce fertile black soil. In the warm growing season, there is abundant heat, enough soil moisture, and lush vegetation. A large quantity of organic residues are returned to the soil before winter. Over the long winters, the large amount of plant residues are decomposed slowly and then transformed into humus that accumulates in the upper layer of the soil. After thousands of years, a thick humus layer formed (60–80 cm in depth). The objectives of this chapter are to review some of the literature on factors affecting fertility of Mollisols in Northeast China, to interpret this literature in the context of climate change, and to highlight management strategies to adapt to climate change.
Article
Soil organic carbon (SOC) is an essential component of the soil-landscape system. It is well recognised that SOC can reduce under some agricultural management practices. In recent years a concerted effort has been undertaken to increase SOC by employing different landscape management practices. Here we compare SOC in a grazing environment to that of an area where cattle have been excluded for over ten years using both a hillslope and whole of soil profile sampling strategy. Surface SOC concentrations (determined by cores) were significantly higher inside the exclusion area when compared to that outside demonstrating a rapid increase in SOC. Whole soil profile (to bedrock) assessment found that SOC decreased with depth both inside and outside of the shelterbelt. While SOC decreased with depth, there were significantly higher surface concentrations inside the exclusion area compared to outside. At depths >20 cm, SOC became increasingly homogenous for both datasets with little difference observed. The results suggest that the influence of the exclusion area on SOC accumulation at the site was only within the top 10-20 cm of the soil profile. The results highlight the importance of soil depth in quantifying SOC within the soil profile and SOC sequestration potential for sites at depth.
Chapter
Full-text available
Modelling soil erosion under any novel conditions, such as a change in climate, inevitably involves an element of extrapolation. The main danger associated with such extrapolation — that of using relationships within the model beyond the range for which they are valid — is reduced if physically-based, rather than empirical, models are used. The WEPP (Water Erosion Prediction Project) model would therefore appear to be a good choice for studies of climate change and erosion, since it is strongly grounded in the physical processes of soil erosion by water. Suitability of the model for climate change studies has recently been enhanced by the addition of the ability to estimate the direct effects of increased atmospheric CO2 upon plant growth. This study uses the hillslope version of WEPP to explore the responses and interactions of the climate-crop-soil system, in terms of shifts in rates and patterns of erosion and deposition upon non-uniform arable hillslopes of the UK South Downs under a changed climate. Earlier results using the more empirical EPIC (Erosion-Productivity Impact Calculator) model are confirmed: future erosion rates under winter cereals may increase, with this increase greatest in wet years, and in an increasingly short period after drilling the crop. In addition, the results indicate that these increases may themselves come in operation in a nonlinear way, with greater impacts in the second quarter of the next century. Erosion rates are likely to increase most at those hillslope sites at which erosion is already most troublesome. Nonetheless, the areas of fields affected by erosion and deposition will probably remain sufficiently limited for future erosion still not to be perceived as a problem by farmers.
Chapter
Full-text available
Since the mid-198os, increases in the global concentrations of greenhouse gases have been paralleled by rising international concern over their potential to affect climate. Concentrations of these gases (most importantly, carbon dioxide, methane, nitrous oxide, tropospheric ozone, chlorofluorocarbons and water vapour) have been observed to increase dramatically during the last 1oo years or so. This rise results from anthropogenic activity. Emissions of the naturally-occurring gases have increased due to modifications of natural cycles by growing human populations, while some new gases (e.g. chlorofluorocarbons) have been added. Atmospheric concentrations of carbon dioxide, for example, have risen by about 26% since the Industrial Revolution (Fig. 1.1): this results both from increased burning of fossil fuels, and from deforestation (Houghton et al. 1990).
Article
Full-text available
This book presents some of the complex interactions between soil hydrology and land use management changes on a watershed scale, and determines the influence of these changes on soil, water and solute dynamics within the vadose zone. The book synthesizes information on several existing soil hydrological models, their capabilities, theories and input requirements, addresses the consequences of land use and management changes for agriculture and presents research results including those from field measurements and modelling. The book also attempts to present results on the possible impacts of climatic change on soil hydrological processes and, to a limited degree, on its impacts on agriculture. lable in any peer-reviewed journal article. This book comprises 19 chapters which start with an introduction to soil hydrology and the application of hydrological models on a mesoscale, while listing the variability of hydrological properties and some of the past, present and future challenges associated with soil hydrology (Chapters 1-2). As there are a number of soil hydrological models that are in the public domain, the book presents a detailed overview of some of these physically/semi-physically based models (Chapter 3), followed by case studies on the application of some of the models to determine the impact of land use and management on various soil hydrological parameters under different climates and ecosystems (Chapters 4-11). The book presents case studies relating to soil water and nutrient management for the sustainable use of agricultural sources (Chapters 12-14), lists different climate data sets for soil hydrological modelling (Chapter 15) and discusses the influence of climate change on soil hydrology, soil erosion, and agriculture (Chapters 16-19). The book also provides the state of the art on hydrological models and is a useful reference for graduate students and scientists working on the interface among soil physics, soil hydrology, land use management, agricultural engineering, agronomy, natural resources and climate change. It also advances our understanding of complex, linked non-linear interactions among soil hydrological properties and processes, and familiarizes the scientific community with the diverse applications of these models.
Chapter
Full-text available
1. Introduction to Soil Hydrology: Processes and Variability of Hydrological Properties 2. Hydrological Modelling at Mesoscopic Scales Using Global Data Sets to Derive Stream Water Availability Models of River Basins 3. An Overview of Some Soil Hydrological Watershed Models 4. Modelling Agricultural Management Systems with APEX 5. Application of the WEPP Model to Hillslopes and Small Watersheds in the USA 6. Application of the WEPP Model to Some Austrian Watersheds 7. Application of the SWAT Model for Ecohydrological Modelling in Germany 8. Spatially Distributed Hydrological Modelling in the Illinois River Drainage Area in Arkansas Using SWAT 9. Hydrological Modelling: A Case Study of the Kosi Himalayan Basin Using SWAT 10. Deep Percolation from Surface Irrigation: Measurement and Modelling Using the Root Zone Water Quality Model 11. CRITERIA-3D: A Mechanistic Model for Surface and Subsurface Hydrology for Small Catchments 12. Effects of Artificial Drainage on Water Regime and Solute Transport at Different Spatial Scales 13. Effect of Land Use and Soil Management on Soil Properties and Processes 14. Land Use and Agricultural Management Systems: Effects on Subsurface Drain Water Quality and Crop Yields 15. Climate Data for Hydrological and Agronomic Modelling 16. Climate Change and Soil Hydrology: European Perspectives 17. Modelling the Impacts of Climate Change on Water Balance and Agricultural and Forestry Productivity in Southern Portugal Using SWAT 18. Soil Erosion by Water Under Future Climate Change 19. Microwave Remote Sensing of Soil Hydraulic Properties.
Article
Full-text available
Objectives WP2: To appraise the current situation with respect to soil erosion using existing data, information systems and models; To establish harmonised criteria and guidelines for the development and use of indicators assessing the present soil erosion risk or state as well as trends in soil erosion over time. Description of the work: 2.1 Identify different forms of soil erosion processes or mechanisms causing soil loss, as well as their relevance in different MS and their inclusion in current soil erosion methodologies − Tillage erosion − Erosion due to harvesting of root crops − Rills and inter-rill erosion − Gully erosion − Bank erosion in rivers and lakes − Snowmelt erosion − Wind erosion − Coastal erosion − Landslides − Internal erosion provoked by groundwater flows − 2.2 Review and analyse existing soil erosion assessment methodologies at European and national scales (including soil erosion indicators) Analyse the results obtained in terms of erosion rates, potential and actual erosion risk, vulnerability areas. Compare the result and check possible inconsistencies. 2.3 Synthesis report of extent of soil erosion in Europe Based on the information derived from the task 2.2 and, after a critical review, a synthesis report of nature and extent of soil erosion should be delivered by the workgroup. This report might include the weak points and uncertainties, which have been pointed out in task 2.2. 2.4 Definition of benchmarks and soil erosion indicators Assessment of existing soil erosion indicator systems: applicability at European and national level. Establish harmonised criteria and guidelines to develop a European soil erosion indicator system.
Article
Full-text available
The loss of inorganic N in drainage water from grazed perennial ryegrass (Lolium perenne L. cv. Talbot) swards in Northern Ireland was studied for 9 yr. Plots (each 0.2-ha area) were hydrologically isolated and artificially drained to V-notch weirs with flow-proportional monitoring of drainage water. Nitrogen, as calcium ammonium nitrate, was applied at 100, 200, 300, 400, or 500 kg N ha-1 yr-1. The efficiency of flow interception by drains decreased on average by 39% during the 9 yr. Annual loss of NO3 in drain flow for the plot receiving 300 kg N ha-1 yr-1 ranged from 16 to 52 kg N ha-1 and was highest after a dry summer. In individual years, NO3/- in drainage water was linearly related to fertilizer N input with 5 to 23% of the added N input being lost. The shape of the NO3/- dose-response curve did not change with time. Annal losses of NH4/+ and NO2/- in drainage water were not related to fertilizer rate, and ranged from 0.2 to 4 kg N ha-1 and 8 to 540 g N ha-1, respectively. Annual flow-weighted mean NO3/-, NH4/+, and NO2/- concentrations usually did not exceed the European Community maximum admissible limits for drinking water below a fertilizer N application rate of 300 kg N ha-1 yr-1. However, the European Community guideline NH4/+ and NO2/- concentrations in salmonid and cyprinid waters were exceeded at application rates ≥100 kg N ha-1 yr-1.
Article
Full-text available
Agricultural intensification of grassland has led to serious imbalances between inputs of nutrients (in purchased fertilizers, feeds and atmospheric deposition) and outputs (mainly milk and meat). Excess nutrients are lost into the wider environment with consequences for soil, water and atmospheric quality. This paper examines the environmental impacts of nitrogen and phosphorus use by the grassland-based agricultural industry of Northern Ireland. Results are presented from a recently completed experimental programme, which was undertaken to define the losses associated with nitrogen inputs to grazed grassland. Also examined is the contention that P use in grassland agriculture is now the major cause of the P enrichment of Lough Neagh, the largest lake in the British Isles. A combination of strategies involving fertilizer management, manure management and dietary manipulation can have a significant impact on the flow and excesses of N and P in grassland systems. However, the rate at which improved management strategies will be introduced in practice depends on regulatory controls, the applicability of new techniques and the financial implications.
Article
Full-text available
The goal of the present study was to assess the impact of selected soil protection measures on soil erosion and retention of rainwater in a 1·14 km ² watershed used for agriculture in the north-east of Austria. Watershed conditions under conventional tillage (CT), no-till (NT) and under grassland use were simulated using the Water Erosion Prediction Project (WEPP) soil erosion model. The period 1961–90 was used as a reference and results were compared to future Intergovernmental Panel on Climate Change (IPCC) scenarios A1B and A2 (2040–60). The simulations for the NT and grassland options suggested runoff would decrease by 38 and 75%, respectively, under the current climatic conditions. The simulation results suggest that, under future climate scenarios, the effectiveness of the selected soil conservation measures with respect to runoff will be similar, or decreased by 16–53%. The actual average net soil losses in the watershed varied from 2·57 t/ha/yr for conventional soil management systems to 0.01 t/ha/yr for grassland. This corresponds to a maximum average annual loss of about 0·2 mm, which is considered to be the average annual soil formation rate and therefore an acceptable soil loss. The current soil/land use does not exceed this limit, with most of the erosion occurring during spring time. Under future climate scenarios, the simulations suggested that CT would either decrease soil erosion by up to 55% or increase it by up to 56%. Under these conditions, the acceptable limits will partly be exceeded. The simulations of NT suggested this would reduce annual soil loss rates (compared to CT) to 0·2 and 1·4 t/ha, i.e. about the same or slightly higher than for NT under actual conditions. The simulation of conversion to grassland suggested soil erosion was almost completely prevented. The selected soil conservation methods maintain their protective effect on soil resources, independent of the climate scenario. Therefore, with small adaptations, they can also be recommended as sustainable soil/land management systems under future climatic conditions. However, based on the available climate scenarios, climate-induced changes in the frequency and intensity of heavy rainstorms were only considered in a limited way in the present work. As the general future trend indicates a strong increase of rainstorms with high intensity during summer months, the results of the present study may be too optimistic.
Article
Full-text available
Irish climate is experiencing changes which have been found to be consistent with those occurring at a global scale. Consequently there is now growing confidence that these changes are largely attributable to global warming. Based on the data from four long-term monitoring, synoptic stations, between 1890 and 2004, mean annual temperatures in Ireland rose by 0.7C. In the absence of strict emissions controls, a doubling of global atmospheric concentrations of CO2 is likely by the end of the twenty-first century. As a consequence, global temperatures are projected to increase by between 1.8C and 4C over the same period depending on the climate sensitivity to increased levels of greenhouse gases. In order to determine the likely impact on Irish temperatures and related climatic variables, this paper illustrates a technique for downscaling Global Climate Model (GCM) output for a selection of sites in Ireland. Results of a weighted ensemble mean, derived from multiple GCMs, are presented in an attempt to address some of the various uncertainties inherent in climate modelling. Projected changes in selected indices of temperature extremes are also presented for a high emissions scenario (A2), as changes in extremes are likely to have a larger and more immediate impact on human society than changes in the mean climate state.
Article
Full-text available
Results are presented from a new version of the Hadley Centre coupled model (HadCM3) that does not require flux adjustments to prevent large climate drifts in the simulation. The model has both an improved atmosphere and ocean component. In particular, the ocean has a 1.25° × 1.25° degree horizontal resolution and leads to a considerably improved simulation of ocean heat transports compared to earlier versions with a coarser resolution ocean component. The model does not have any spin up procedure prior to coupling and the simulation has been run for over 400 years starting from observed initial conditions. The sea surface temperature (SST) and sea ice simulation are shown to be stable and realistic. The trend in global mean SST is less than 0.009 °C per century. In part, the improved simulation is a consequence of a greater compatibility of the atmosphere and ocean model heat budgets. The atmospheric model surface heat and momentum budget are evaluated by comparing with climatological ship-based estimates. Similarly the ocean model simulation of poleward heat transports is compared with direct ship-based observations for a number of sections across the globe. Despite the limitations of the observed datasets, it is shown that the coupled model is able to reproduce many aspects of the observed heat budget.
Article
Full-text available
We review published stratigraphic, archaeological and pedosedimentary evidence in order to reconstruct the history of soil erosion in China. Documentary evidence of climatic and flood events of the Yellow River and modern hydrological and meteorological data are synthesised to analyse the history of past human activity and its effects on soil erosion intensity during four nested periods of time during the Quaternary. The most intensive period of erosion during the Quaternary was in the Holocene. During the Holocene, intervals of intensive soil erosion occurred at 7500–7000 BP, 200 BCE–0 CE, 1000–1600 CE (Christian era) and during the 1930s, 1950s and the later part of the 1960s of the last century. Large-scale human activity including warfare during early Chinese history, population migration, the inner wars in 1930s, the Cultural Revolution and the recent national campaign to aid soil and water conservation are all closely related to the rate of soil erosion on the Loess Plateau and to sediment loads in the Yellow River. Overall, soil erosion during the transition from dry-cool to wet-warm climates was more intense than during wet-warm and cool-dry climatic episodes, but serious accelerated soil erosion has occurred during the last 2,500years because of man-induced devastation of vegetation and other anthropogenic disturbance of the environment. Modern rates of soil erosion on the Loess Plateau are a combination of both intensive natural and human-induced erosions and are some four times greater than occurred in the geological past. The recent implementation of soil and water conservation measures has decreased sediment load in the Yellow River by 25%.
Article
Full-text available
 A global, three-dimensional climate model, developed by coupling the CCCma second-generation atmospheric general circulation model (GCM2) to a version of the GFDL modular ocean model (MOM1), forms the basis for extended simulations of past, current and projected future climate. The spin-up and coupling procedures are described, as is the resulting climate based on a 200 year model simulation with constant atmospheric composition and external forcing. The simulated climate is systematically compared to available observations in terms of mean climate quantities and their spatial patterns, temporal variability, and regional behavior. Such comparison demonstrates a generally successful reproduction of the broad features of mean climate quantities, albeit with local discrepancies. Variability is generally well-simulated over land, but somewhat underestimated in the tropical ocean and the extratropical storm-track regions. The modelled climate state shows only small trends, indicating a reasonable level of balance at the surface, which is achieved in part by the use of heat and freshwater flux adjustments. The control simulation provides a basis against which to compare simulated climate change due to historical and projected greenhouse gas and aerosol forcing as described in companion publications.
Article
Full-text available
Spatial downscaling of climate change scenarios can be a significant source of uncertainty in simulating climatic impacts on soil erosion, hydrology, and crop production. The objective of this study is to compare responses of simulated soil erosion, surface hydrology, and wheat and maize yields to two (implicit and explicit) spatial downscaling methods used to downscale the A2a, B2a, and GGa1 climate change scenarios projected by the Hadley Centre’s global climate model (HadCM3). The explicit method, in contrast to the implicit method, explicitly considers spatial differences of climate scenarios and variability during downscaling. Monthly projections of precipitation and temperature during 1950–2039 were used in the implicit and explicit spatial downscaling. A stochastic weather generator (CLIGEN) was then used to disaggregate monthly values to daily weather series following the spatial downscaling. The Water Erosion Prediction Project (WEPP) model was run for a wheat–wheat–maize rotation under conventional tillage at the 8.7 and 17.6% slopes in southern Loess Plateau of China. Both explicit and implicit methods projected general increases in annual precipitation and temperature during 2010–2039 at the Changwu station. However, relative climate changes downscaled by the explicit method, as compared to the implicit method, appeared more dynamic or variable. Consequently, the responses to climate change, simulated with the explicit method, seemed more dynamic and sensitive. For a 1% increase in precipitation, percent increases in average annual runoff (soil loss) were 3–6 (4–10) times greater with the explicit method than those with the implicit method. Differences in grain yield were also found between the two methods. These contrasting results between the two methods indicate that spatial downscaling of climate change scenarios can be a significant source of uncertainty, and further underscore the importance of proper spatial treatments of climate change scenarios, and especially climate variability, prior to impact simulation. The implicit method, which applies aggregated climate changes at the GCM grid scale directly to a target station, is more appropriate for simulating a first-order regional response of nature resources to climate change. But for the site-specific impact assessments, especially for entities that are heavily influenced by local conditions such as soil loss and crop yield, the explicit method must be used.
Article
Full-text available
Global climate has changed over the past century. Precipitation amounts and intensities are increasing. In this study we investigated the response of seven soil erosion models to a few basic precipitation and vegetation related parameters using common data from one humid and one semi-arid watershed. Perturbations were made to inputs for rainfall intensities and amounts, and to ground surface cover and canopy cover. Principal results were that: soil erosion is likely to be more affected than runoff by changes in rainfall and cover, though both are likely to be significantly impacted; percent erosion and runoff will likely change more for each percent change in rainfall intensity and amount than to each percent change in either canopy or ground cover; changes in rainfall amount associated with changes in storm rainfall intensity will likely have a greater impact on runoff and erosion than simply changes in rainfall amount alone; changes in ground cover have a much greater impact on both runoff and erosion than changes in canopy cover alone. The results do not imply that future changes in rainfall will dominate over changes in land use, since land use changes can often be drastic. Given the types of precipitation changes that have occurred over the last century, and the expectations regarding changes over the next century, the results of this study suggest that there is a significant potential for climate change to increase global soil erosion rates unless offsetting conservation measures are taken.
Article
Full-text available
Erosion is a major threat to soil resources in Europe, and may impair their ability to deliver a range of ecosystem goods and services. This is reflected by the European Commission's Thematic Strategy for Soil Protection, which recommends an indicator-based approach for monitoring soil erosion. Defined baseline and threshold values are essential for the evaluation of soil monitoring data. Therefore, accurate spatial data on both soil loss and soil genesis are required, especially in the light of predicted changes in climate patterns, notably frequency, seasonal distribution and intensity of precipitation. Rates of soil loss are reported that have been measured, modelled or inferred for most types of soil erosion in a variety of landscapes, by studies across the spectrum of the Earth sciences. Natural rates of soil formation can be used as a basis for setting tolerable soil erosion rates, with soil formation consisting of mineral weathering as well as dust deposition. This paper reviews the concept of tolerable soil erosion and summarises current knowledge on rates of soil formation, which are then compared to rates of soil erosion by known erosion types, for assessment of soil erosion monitoring at the European scale.
Article
Full-text available
Climate in the United States is expected to change during the 21st century, and soil erosion rates may be expected to change in response to changes in climate for a variety of reasons. This study was undertaken to investigate potential impacts of climate change on soil erosion by water. Erosion at eight locations in the United States was modeled using the Water Erosion Prediction Project model modified to account for the effects of atmospheric CO2 concentrations on plant growth. Simulated climate data from the U.K. Meteorological Office's Hadley Centre HadCM3 Global Circulation Model were used. The results indicated a complex set of interactions between the several factors that affect the erosion process. Direct effects of rainfall increases and decreases to runoff and erosion increases and decreases were observed but were often not dominant. One of the key factors of change in the system was the biomass production. Changes in soil moisture, atmospheric CO2 concentration, temperature, and solar radiation each impacted the biomass production at differing levels at the eight different sites. Different types of changes occurring at different periods of the year also complicated the response of the system. Overall, these results suggest that where precipitation increases are significant, erosion can be expected to increase. Where precipitation decreases occur, the results may be more complex due largely to interactions of plant biomass, runoff, and erosion, and either increases or decreases in overall erosion may be expected.
Chapter
The sensitivity of European soils to ultimate physical degradation is assessed by using the model of Stocking and Pain [35] to calculate their life span for commercial agricultural production. Assuming a soil loss tolerance of 1 t/ha, soils shallower than 0Ŀ30 m for sandy loams and 0Ŀ25 m for clay loams will reach ultimate physical degradation within 50–75 years wherever the mean annual erosion rate exceeds 20 t/ha. Data on present-day erosion rates reveal that there are certainly parts of the Mediterranean countries and the sandy and loamy belt of northern Europe in danger of serious degradation. The data undoubtedly understate the severity of the problem in the Mediterranean where millions of hectares of land are badly eroded and have been abandoned. The extent of the area at risk of or already affected by ultimate physical degradation in the European Community as a whole is not known. A suitable methodology, combining erosion modelling and assessment techniques, needs to be devised to determine this.
Article
Reviews scientific work done on soil erosion prediction, soil formation and the effect of erosion on productivity so far as they affect agricultural practices in the US. Based on experience and some past researches some advisory bodies now recommend a soil tolerance value of 5 tons per acre per year, but some dispute continues about the value of this particular guideline.-from Author
Article
This study of agricultural field in Omagh, northern Ireland, shows that soil erosion by water can occur even in areas with stable soils. Soil erosion is rare in Ireland, even though the island has a maritime climate, since its soils are rich in clay, and the adhesion between the clay particles produces low erodibility; also, permanent grassland covers much of the island, protecting the soil. However, in October 2008, erosion was seen in a field outside Omagh. There was heavy convectional and high-intensity rainfall while the field was being ploughed to establish a new grass sward and the soil therefore bare; also, since the field had been rolled before re-seeding, the infiltration rate of the soil was reduced, leaving it vulnerable to runoff. The storms moved soil, especially in the steeper parts of the field, towards the bottom, carving out a network of channels called rills; the loss of large amount of soil is likely to reduce the field's fertility and grass yields, while sediment runoff may pollute nearby watercourses.
Article
One consequence of global change will be shifts in the probability of occurrence of soil erosion by water. This could have serious consequences for those areas of the world which are present-day 'hotspots' for erosion. By means of a case study, this paper suggests an approach to quantifying the change in risk of serious erosion for sites in such areas. The case study focuses on future erosion under intensive soya bean cultivation in the Mato Grosso area of Brazil. On the area's highly erodible latosols, current erosion problems are severe. Scenarios of change future climate Ž. change are taken from general circulation models GCMs and used to perturb current-climate Ž Ž. . weather data. These are input to an erosion model water erosion prediction project WEPP-CO2 , together with local knowledge regarding current and probable future land use, in order to estimate future changes in erosion rates. WEPP-simulated average annual sediment yield increases in one of the scenarios and decreases in the other two, reflecting the range of uncertainty in predictions of future rainfall. Using the 'best-guess' climate scenario from the UK Meteorological Office's HADCM2 GCM, the increase in mean annual sediment yield is 27%. Increases are disproportionately greater in wetter years. Average rates for individual months increase by over 100%. Erosion increases most on those parts of the hillslope profile which are currently hardest-hit by erosion. At present, an annual sediment yield of 5 t ha y1 is currently exceeded in about 1 year in 2. The HADCM2 simulations suggest that an equal or greater rate will occur in about 70% of years by around 2050. A rate of at least 10 t ha y1 yr y1 is currently exceeded in about 1 year in 5. The
Article
A slow-moving, occluded weather front brought over 50mm of rainfall in 24 hours to eastern Scotland on 31 March 1992, but rainfall intensities rarely exceeded 4 mm hr−1. Nevertheless, rill erosion caused widespread damage to vulnerable, recently seeded fields, unprotected by vegetation. A reconnaisance survey of 195 fields in the Forfar area of Angus revealed that erosion was particularly severe in bare soil ploughed in a downslope direction; 58 per cent of fields were affected and 30 per cent suffered rill erosion. Of fields with young crops, 10 per cent suffered some erosion and only 2 per cent were rilled. No erosion affected grazing land. At three sites, the volume of redeposited soil in closed depressions gave estimates of soil loss of 1.17–2.22 t ha−1, far in excess of both long-term annual averages and of probable soil loss tolerances for the region. The risk of events of similar magnitude has been estimated for the planting and early growing season using maximum recurrence intervals (RI) based on 1950–1991 rainfall records. For Dundee (15 km south of the study area), RI < 75 yr for March, RI < 32 yr for April, and RI < 24 yr for March and April combined. The risk of an event of such magnitude occurring in March is therefore only half the risk of an April occurrence, indicating that late planting and crop growth increase the erosion risk. Estimates of rainfall erosivity based on rainfall intensities do not adequately predict the erosion hazard in northern Britain, where prolonged frontal rain of low intensity may cause much damage. It is suggested that under conditions of saturated overland flow, sediment yield from rilled fields is related primarily to rainfall duration, and thus large sediment yields are possible where rilling is initiated.
Article
This book summarizes state-of-the-art knowledge on the potential impacts of climate change on agriculture. The book begins by introducing the nonspecialist to the causes of climate change, and reviews the main climate change drivers and impacts. It then goes on to review all major aspects of climate change impact on agriculture in detail. The scope is very broad indeed--the authors consider agricultural greenhouse gas emissions; the effects of raised CO and climate change on crop yield (discussing in some detail the effects on vegetation); possible impacts on pests, weeds, and diseases; impacts on soils; and the effects on water resources and sea level rise. The final four chapters expand the science described in earlier chapters to the global level, providing an analysis of impacts of climate change, then examining in detail the regions at greatest risk from climate change and possible implications for future food security, and finishing with a chapter on adaptation, economics, and policy.
Article
Proper spatial and temporal treatments of climate change scenarios projected by General Circulation Models (GCMs) are critical to accurate assessment of climatic impacts on natural resources and ecosystems. The objective of this study was to evaluate the site-specific impacts of climate change on soil erosion and surface hydrology at the Changwu station of Shaanxi, China using a new spatiotemporal downscaling method. The Water Erosion Prediction Project (WEPP) model and climate change scenarios projected by the U.K. Hadley Centre's GCM (HadCM3) under the A2, B2, and GGa emissions scenarios were used in this study. The monthly precipitation and temperature projections were downloaded for the periods of 1900–1999 and 2010–2039 for the grid box containing the Changwu station. Univariate transfer functions were derived by matching probability distributions between station-measured and GCM-projected monthly precipitation and temperature for the 1950–1999 period. The derived functions were used to spatially downscale the GCM monthly projections of 2010–2039 in the grid box to the Changwu station. The downscaled monthly data were further disaggregated to daily weather series using a stochastic weather generator (CLIGEN). The HadCM3 projected that average annual precipitation during 2010–2039 would increase by 4 to 18% at Changwu and that frequency and intensity of large storms would also increase. Under the conventional tillage, simulated percent increases during 2010–2039, compared with the present climate, would be 49–112% for runoff and 31–167% for soil loss. However, simulated soil losses under the conservation tillage during 2010–2039 would be reduced by 39–51% compared with those under the conventional tillage in the present climate. The considerable reduction in soil loss in the conservation tillage indicates the importance of adopting conservation tillage in the region to control soil erosion under climate change.
Article
The CSIRO coupled model has been used in a “transient” greenhouse experiment. This model contains atmospheric, oceanic, comprehensive sea-ice (dynamic/thermodynamic plus leads), and biospheric submodels. The model control run (over 100 years long) employed flux corrections and displayed only a small amount of cooling, mainly at high latitudes. The transient experiment (1% increase in CO2 compounding per annum) gave a 2°C warming at time of CO2 doubling. The model displayed a “cold start” effect with a (maximum) value estimated at 0.3°C. The warming in the transient run had an asymmetrical response as seen in other coupled models, with the Northern Hemisphere (NH) warming more than the Southern Hemisphere (SH). However, the land surface response in this model is different from some other transient experiments in that there is not a pronounced drying of the midlatitudes in the NH in summer. In the control run the ice model gave realistic ice distributions at both poles, with the NH ice in particula...
Article
Modelling future temperature changes is a crucial step in the climate change impacts analysis stage for a wide range of environmental and socioeconomic sectors. A scale mismatch exists, however, between the coarse spatial resolution at which general circulation models (GCMs) project future climate change scenarios, and the finer spatial resolution at which impact modellers require such projections. Various downscaling techniques can be used to bridge this gap, with statistical downscaling methods emerging as a popular, low-cost and accessible means of developing site-specific future scenarios. Despite its widespread use, little attention has been paid to some of the key issues in statistical downscaling which are central to the development of the future scenarios, including GCM grid-box choice and the effects of modifying the calibration period. In this study, such issues are examined with respect to the development of site-specific future temperature scenarios for nine climatological stations across Northern Ireland. Results indicate that the more remote grid box of the two analysed is most strongly correlated with maximum and minimum temperatures, illustrating the importance of examining potential spatial offsets in the predictor-predictand relationship. In addition, modifications to the calibration period result in only minor differences to seasonal calibration and validation values as well as resultant future projections, indicating that longer calibration periods do not always offer improvements over shorter periods. Future downscaled scenarios reveal considerable warming across all sites and seasons, with large inter-GCM differences apparent. This underlines the importance of employing multiple GCMs and emissions scenarios to help address the uncertainties inherent in global climate modelling. This study illustrates the potential of statistical downscaling methods in generating high-resolution future climate change scenarios appropriate to the requirements of impact modellers, provided a thorough analysis of some of the key issues that shape the character of the future scenarios are fully explored. Copyright  2011 Royal Meteorological Society
Article
Future climate change is expected to impact the extent, frequency, and magnitude of soil erosion in a variety of ways. The most direct of these impacts refers to the projected increase in the erosive power of rainfall, whilst other more indirect impacts include changes in plant biomass and shifts in land use to accommodate the new climatic regime. Given the potential for climate change to increase soil erosion and its associated adverse impacts, modelling future rates of erosion is a crucial step in its assessment as a potential future environmental problem, and as a basis to help advise future conservation strategies. Despite the wide range of previous modelling studies, in the majority of cases limitations are apparent with respect to their treatment of the direct impacts (changed climate data), and their failure to factor in the indirect impacts (changing land use and management). In this study, these limitations are addressed in association with the modelling of future soil erosion rates for a case study hillslope in Northern Ireland using the Water Erosion Prediction Project (WEPP) model. The direct impacts are handled using statisti-cal downscaling methods, enabling the generation of site-specific, daily resolution future climate change scenarios, and a simple sensitivity analysis approach is employed to investigate the previously unstud-ied impacts of sub-daily rainfall intensity changes. Finally, the frequently neglected indirect impacts are examined using a scenarios-based approach. Results indicate a mix of soil erosion increases and decreases, depending on which scenarios are considered. Downscaled climate change projections in isolation gen-erally result in erosion decreases, whereas large increases are projected when land use is changed from the current cover of grass to a row crop which requires annual tillage, and/or where large changes in sub-daily rainfall intensity are applied. The overall findings illustrate the potential for increased soil erosion under future climate change, and illuminate the need to address key limitations in previous studies with respect to the treatment of future climate change projections, and crucially, the factoring in of future land use and management.
Article
Group I, 2001; U.S. National Assessment Synthesis Team (NAST), 2001). Interestingly, analysis of climatol- Climate change can affect agricultural production and soil and ogy throughout the contiguous USA has revealed an water conservation. The potential for global climate changes to in- upward trend in total precipitation and a bias toward crease the risk of soil erosion is clear, but the actual damage is not. The objectives of this study were to develop a method for downscaling more intense rainfall events during the last century (Soil monthly climate forecasts to daily weather series using a climate and Water Conservation Society (SWCS), 2003). As was generator (CLIGEN), and to determine the potential impacts of pro- stated in that report, the potential for such changes to jected mean and variance changes in precipitation and temperature increase the risk of soil erosion and related environmen- on soil erosion and wheat (Triticum Aestivum L.) yield. Monthly tal consequences is clear, but the actual damage is not forecasts for the periods of 1950-1999 and 2056-2085 for the Okla- known and needs to be assessed. The report called for homa region, projected by a general circulation model (HadCM3), more detailed assessments of the impacts and environ- were used. Projected mean and variance changes in precipitation and mental consequences in various regions, seasons, and temperatures between the two periods were satisfactorily incorpo- agricultural production systems (SWCS, 2003). rated into CLIGEN input parameters derived for the El Reno station, Many variables such as precipitation, temperature, Oklahoma, and future transitional probabilities of precipitation occur- rence were estimated as a linear function of historical monthly precipi- CO2 concentration, and solar radiation affect soil ero- tation. Five climate change scenarios were constructed, and the Water sion and crop production. The impact of each variable Erosion Prediction Project (WEPP) model was run for each combina- is different and complex. A change in precipitation, for tion of five climate scenarios and three tillage systems. A 50% increase example, affects soil erosion and crop growth differently in CO2 resulted in some 26% increase in wheat yield. At that elevated if that change comes from a change in precipitation CO2 level, projected decrease in total precipitation decreased surface frequency (number of wet days) versus a change in runoff, soil loss, and wheat yield. However, predicted changes in precipitation intensity (rainfall amount per day) as precipitation variance increased runoff by 15 to 17%, and increased shown by Pruski and Nearing (2002a). Furthermore, soil loss by 10 and 19% under conservation and conventional tillage, the interactive effects among climatic variables can be respectively. Predicted increase in mean temperature reduced wheat significant. The actual effects of individual variables and yield by 31%, and increased soil loss by 40 and 19% under conservation and conventional tillage, respectively. Under the assumed climate their interactions would ultimately depend upon their change, predicted average soil loss under conventional tillage was individual and/or collective impacts on plant growth and about 2.6 times that under conservation tillage and 29 times that under biomass production. no-till. With all changes considered, predicted average wheat yield Impact of global climate change, including changes in during 2056-2085, compared with the present climate at the present precipitation, temperature, and CO2 on crop production, CO2 level, would decrease by 12%; runoff would increase by 7%; has been evaluated by many researchers (e.g., Rosen- and soil loss would increase by 8% in all tillage systems. Overall zweig and Parry, 1994; Mearns et al., 1997; Semenov results indicate that adoption of conservation tillage and no-till will and Porter, 1995; Mavromatis and Jones, 1998). Mean be effective in controlling soil erosion under projected climate change and variance changes in both precipitation and tempera- used in this study. ture were considered when generating climate change scenarios in those studies, and their results indicated that changes in climate variability (as measured by vari-
Book
The first part of this book deals with the distribution and frequency of erosion, the mechanics of the various processes of erosion, and the techniques used to predict erosion rates and to measure erosion. In the second part the author discusses the strategies for erosion control and the wide range of conservation practices.-R.A.H.