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Toward a Formal Definition of Water Scarcity in Natural-Human Systems
Water Resources Research
Abstract
Water scarcity may appear to be a simple concept, but it can be difficult to apply to
complex natural-human systems. While aggregate scarcity indices are straightforward to
compute, they do not adequately represent the spatial and temporal variations in water
scarcity that arise from complex systems interactions. The uncertain effects of future
climate change on water scarcity add to the need for clarity on the concept of water scarcity.
Starting with a simple but robust definition—the marginal value of a unit of water we—
highlight key aspects of water scarcity and illustrate its many biophysical and
socioeconomic determinants. We make four central observations. First, water scarcity varies
greatly across location, time, and a multitude of uses that are valued either directly or
indirectly by society. Second, water scarcity is fundamentally a normative, anthropocentric
concept and, thus, can and should be distinguished from the related, purely descriptive
notion of water deficit. While such an anthropocentric perspective may seem limiting, it has
the potential to encompass the vast range of interests that society has in water. Third, our
ability to understand and anticipate changes in water scarcity requires distinguishing
between the factors that affect the value or benefits of water from those affecting the costs
of transforming water in space, time and form. Finally, this robust and rigorous definition of
water scarcity will facilitate better communication and understanding for both policymakers
and scientists.
... At the global level, the "planetary boundaries" for freshwater availability have not been crossed (Steffen et al. 2015) and on annual basis sufficient Fig. 1 Milestones of addressing water crisis in the development discourse freshwater is available to meet the increasing water demand. However, the demand for and availability of water fluctuate in spatial and temporal variations as a result of natural hydrological variability (Mekonnen and Hoekstra 2016; Liu et al. 2017), socioeconomic changes, or as a consequence of inadequate planning and management approaches with lacking institutional capacity to provide the necessary water services and develop infrastructure to control the storage, distribution, and access to water resources (FAO 2012;Jaeger et al. 2013). This leads to water scarcity in several parts of the world during specific times of the year. ...
... Challenges of water management are always determined by local hydro-climatic and socioeconomic conditions (FAO 2012;Jaeger et al. 2013). Hence all activities related to water management ranging from capacity building, investments, infrastructure construction, implementing new technologies to gather information about water demand and availability should always consider and be adapted to the local conditions. ...
The studies selected for this contribution form part of the inter- and transdisciplinary exchange conducted in the scope of the International Conference Series: Water Security and Climate Change (WSCC). In this chapter, we summarize the main messages emerging from the contributions published in this volume and discussed in the scope of the WSCC conference series.
... At the global level, the "planetary boundaries" for freshwater availability have not been crossed (Steffen et al. 2015) and on annual basis sufficient Fig. 1 Milestones of addressing water crisis in the development discourse freshwater is available to meet the increasing water demand. However, the demand for and availability of water fluctuate in spatial and temporal variations as a result of natural hydrological variability (Mekonnen and Hoekstra 2016; Liu et al. 2017), socioeconomic changes, or as a consequence of inadequate planning and management approaches with lacking institutional capacity to provide the necessary water services and develop infrastructure to control the storage, distribution, and access to water resources (FAO 2012;Jaeger et al. 2013). This leads to water scarcity in several parts of the world during specific times of the year. ...
... Challenges of water management are always determined by local hydro-climatic and socioeconomic conditions (FAO 2012;Jaeger et al. 2013). Hence all activities related to water management ranging from capacity building, investments, infrastructure construction, implementing new technologies to gather information about water demand and availability should always consider and be adapted to the local conditions. ...
Agriculture is a major economic activity of rural people in Bangladesh and a fundamental pillar for ensuring food security in the country. Agricultural productivity in coastal zone of Bangladesh has been decreasing in the last decade due to water scarcity caused by groundwater contamination coming from soil salinity. This paper aims at assessing the progress of soil salinity and at identifying the effects of salinity intrusion on agricultural production using the perception of the farmers in the Upazilas (sub-district) of Satkhira district located in the southwest coastal region of Bangladesh. Accordingly, landsat images of the years 2006 and 2016 were analyzed to assess and map the progress of soil salinity. In 2006, soils of none of the study areas had electrical conductivity (EC) beyond 16 dS/m. But in 2016, a total of 5644 ha in the two study areas combined had EC values higher than 16 dS/m. Only a very few varieties of crops can sustain in soils with EC values higher than 16 dS/m. Furthermore, interviews with 300 farmers of 15 randomly selected locations of the two Upazilas were conducted and the results validated by statistical tests and compared with the Landsat Images. Farmers identified water scarcity for irrigation purposes as the most prominent effect of salinity intrusion followed by a decline of prices in the livestock market.
... These changes are taking place in the context of a region that has a growing demand for water resources from a range of stakeholders, and a projected climate future of increased water scarcity. In the coming decades, water demand is anticipated to increase with projected population growth, an upsurge of development, expansion of agricultural irrigation, and the need for environmental flows, i.e., leaving water in rivers and streams as habitat for fish, including federally-listed threatened and endangered species (Jaeger et al., 2013). ...
... The results of their study aligned with other findings about temperature and precipitation. They found that for every 1.6 • C increase in annual mean temperature, there will be a roughly 15% decrease in summer flow in the lower Willamette River Basin (Jaeger et al., 2013). In addition, fire risk is projected to increase across the entire state, with large increases in the Willamette Valley (Mote et al., 2019). ...
This study investigates the institutional, social, and ecological dynamics that influence regional water governance and individual vineyard owners' decision making in global wine regions. Global wine grape production has grown steadily over the past 20 years, and climate change has emerged as a driver of transformation in wine regions resulting in a range of impacts. Changes to the climate are anticipated to accelerate in the future and present a number of challenges for wine regions; including risks to human systems, e.g., agriculture, labor, and economics, as well as ecological systems, e.g., surface and groundwater. Water is a critical resource for environmental and economic sustainability in wine regions, and vulnerability to freshwater resources in wine producing regions is expected to increase as wine regions experience climate extremes like heat and drought. We use the Institutional-Social-Ecological Dynamics (ISED) framework to help understand individual vineyard owner decision making about water management within the context of institutional, social, and ecological systems. We ask how the relationships between these systems impact outcomes for individual grape farmers adapting to climate challenges. Our empirical research uses document review and interviews with vineyard owners, planners, and natural resource managers in wine regions in Oregon, USA and Tasmania, Australia as a means to explore climate vulnerabilities and adaptation approaches. Subsequently we focus on an example vignette in each region to better understand individual decision making at the farm scale within the unique institutional, social, and ecological contexts identified in each region. Our cases highlight the finding that entrenched institutional regimes, in the context of ecological variability contribute to a social unevenness in access to water. Landowner conflict over water resources is likely to increase in the context of a hotter, drier climate in regions with wine industry growth. Individual vineyard owners have a range of attitudes and approaches to climate change planning and management; and adaptation around water is dependent on both economic resources and social values. Lessons from the individual farm scale help to inform broader implications of how institutional, social, and ecological drivers influence opportunities or barriers to the implementation of climate change adaptation practices in wine regions.
... (Shiklomanov, 1993;Brown & Matlock, 2011). Technology and infrastructure play a crucial role in assessment of water resource vulnerability (Raskin et al., 1997;Jaeger et al., 2013). Two additional indices -India Water Stress Index (WSI) also known as Potential Storage Index developed by Columbia Water Centre, 2011 and Drought Index developed by Government of India (2012a)have been added to the water resources vulnerability approach by the authors because these two indices also consider technology and infrastructure in assessing water resource vulnerability (Table 1). ...
... Evolution of these approaches to water scarcity reflects a paradigm shift from 'water use' towards 'water sustainability'. These evolving approaches depict anthropocentric valuation or 'plural normative views' on water use, access, and value (Hamlin, 2000;Feitelson, 2012;Jaeger et al., 2013). The S. Katyaini Falkenmark Index of approach I considers population growth as an inducer of water scarcity as rising populations lead to increase in water use. ...
... As long as FEW resources are consistently available and relatively inexpensive or easily substitutable (e.g., energy from coal vs. hydropower), FEW transactions proceed as low-friction commerce. Were this a single sector model, this characterization of scarcity impacts would be as simple as it sounds; as the perceived availability of a resource decreases, the marginal cost of the resource should increase with respect to both the current and potential future scarcity [65]. In some cases, the costs can increase more rapidly than the system can respond, and be perceived as a crisis. ...
... In retrospect, technological change, innovation, and the importation of capital from outside the system under study generally allows those systems to escape a scarcity-based conflict [72]. Still, responses to FEW system problems often amount to calls for increases in allocative efficiencies or technological change that in effect remove scarcity via a shift in the demand curve (sensu [65]), or what is effectively a redefinition of scarcity (e.g., [54]). This aspect of innovation calls into question the initial characterization of scarcity, and reinforces the need for conceptual clarity for which we are advocating. ...
There is an increasing appreciation that food–energy–water (FEW) nexus problems are approaching criticality in both the developing and developed world. As researchers and managers attempt to address these complex resource management issues, the concept of the FEW nexus has generated a rapidly growing footprint in global sustainability discourse. However, this momentum in the FEW nexus space could be better guided if researchers could more clearly identify what is and is not a FEW problem. Without this conceptual clarity, it can be difficult to defend the position that FEW innovations will produce desired outcomes and avoid unintended consequences. Here we examine the growing FEW nexus scholarship to critically evaluate what features are necessary to define a FEW nexus. This analysis suggests that the FEW nexus differs from sector-focused natural resource or sustainability problems in both complexity and stakes. It also motivates two new foci for research: the identification of low-dimension indexes of FEW system status and approaches for identifying boundaries of specific FEW nexuses.
... Although individuals might observe retreating glaciers and note less water, they also acknowledge that the current water realities are shaped by water governance (Rasmussen 2015). Water scarcity is as much a matter of equity as it is contingent on environmental conditions (Jaeger et al. 2013). ...
... Currently, most studies construct the problem as a glacier, water, and climate change issue. Ultimately, though, water scarcity is a socioeconomic issue (Jaeger et al. 2013). Human beings determine how much water to use and how (and to whom) it gets distributed. ...
... The problem with this defnition is it combines water deficit and water scarcity in one defintion, which can be misleading or inaccurate in circumstances where there is no water deficit but only water scarcity. Jaeger et al. [7] explain that water scarcity should be distinguished from water deficit. Water scarcity is normative and anthropocentric in nature because it varies based on temporal, spatial and social values (direct and indirect ) regarding multiple water uses. ...
... 1258) definition of water scarcity as "the opportunity costs of forgone human options that result from a specific water use decision". Jaeger et al. [7] explain that water deficit is purely descriptive. Kampas and Rozakis [8] (p. ...
The Kenyan government has made significant advances in water resources management at the local authority (county) level with little or no cooperation at the drainage basin level. Research on critical determinants of cooperation amongst transboundary water negotiation teams is limited. In this paper, we assess whether personal attribute diversity (PAD) is a stronger factor than demographic diversity (gender, age, and education play) in determining whether the negotiation team will cooperate or make unilateral actions. We use a negotiation game to study decisions taken by water policymakers. After that, we conduct a multiple discriminant analysis (MDA) to assess the influence of PAD, gender, age, and education on water negotiation outcomes. The findings indicate that PAD plays a significant role in determining whether the group will cooperate or compete. Gender, education, and age barely influence the outcome. Only upon removal of the PAD variable do we see an increase in the discriminant power of gender and education. Age has minimal influence on the negotiation outcomes. We apply the research at a lower level of governance (Nzoia River Basin). However, results might be extrapolated to a bigger basin, like the Nile Basin, through future multiple level analysis which takes account of the complex socio-technical systems.
... First, this study starts by simulating these two appropriate tariff structures according to their basic framing principles, and pioneers identifying the intrinsic merits and demerits of these two price structures, rather than conducting policy evaluations as in the previous literature. Second, the policy evaluations in the literature have been conducted under the assumption that residents respond to marginal price under IBTs, which is nonlinear tariff structure; Hewitt and Hanemann [10] used the "as if" theory proposed by Friedman [11] (pp. [19][20] to support the assumption that on average households do behave "as if" they knew the rate structure. However, this assumption may not hold under IBTs according to the results of the subsequent empirical studies. ...
... (1) Marginal social cost pricing rule. Jaeger et al. [19] define water scarcity as the marginal value of a unit of water on the demand curve. This definition of water scarcity is seen as fundamentally normative and anthropocentric. ...
Water is a basic necessity and its allocation and utilization, especially pricing policies, impose various social, economic, and ecological impacts on social groups. Increasing block tariffs (IBTs) has gained popularity because it is expected to incentivize water conservation while protecting poor people benefiting from the redistribution effects because of its nonlinear tariff structure. However, it results in price distortion under certain circumstances. Researchers have also proposed an alternative practical price system and a uniform tariff with rebate (UTR), with the price level set equal to the marginal social cost and a fixed rebate allocated to the poor groups. This study proceeds with a simulation of the two pricing systems, UTR and IBTs, and empirically explores their fundamental merits and limitations. The results confirm the theoretical perspective that a water price system, compared with an optimal tariff system, simultaneously achieves multiple goals to the greatest possible extent.
... Existing research on measuring the economic impacts of droughts on agriculture often focuses on national-level damage assessments without considering spatially distributed data and typically examines specific drought events (COPA-COGECA, 2003;Trenczek et al., 2022). This approach can lead to biased estimates, as droughts can vary greatly across different locations and times (Jaeger et al., 2013;Samaniego et al., 2013), suggesting the need for consistent, highresolution impact assessments (Meyer et al., 2013). Our analysis reveals that high-resolution damage assessment using regional-85 level data provide a more accurate quantification of crop-specific damages, which might not be captured by assessments using national-level data. ...
Assessing the economic implications of droughts has become increasingly important due to their substantial impacts on agriculture. Existing empirical analyses for drought damages are often conducted on a national scale without spatially distributed data, which might bias estimates. Furthermore, the cumulative effects of multiple weather extremes, such as heat or preceded frost co-occurring with drought, are often overlooked. Measuring the direct biophysical impacts of such extremes on agriculture is essential for more precise risk assessment. This study presents a comprehensive economic impact assessment framework to measure the cumulative damages of droughts and other hydro-meteorological extremes on agriculture, focusing on eight major field crops in Germany. By utilizing a statistical yield model, we isolate the effects of multiple extremes on crop yields from other influencing factors (such as pests & diseases, farm management) and analyze their contribution to farm revenue losses during droughts at the district level from 2016–2022. Our findings indicate that the average annual direct biophysical damage caused by extremes under drought conditions during this period amounts to € 781 million across Germany. The study also reveals that biophysical impacts of extremes alone account for 60 % of reported revenue damages during widespread drought years. For maize, direct biophysical damage explains up to 97 % (2018) of revenue losses. Additionally, comparison of national-level damage estimates using aggregated and spatially disaggregated data shows that the aggregated data matches overall results, but diverges for maize and wheat, highlighting the importance of spatially distributed damage assessment. In this paper, we provide detailed estimates of extremes-driven direct biophysical damages at the district level, offering a high-resolution understanding of the spatial and temporal variability of these impacts. Assessing the extent of revenue losses resulting from these extremes alone can provide valuable insights for the development of effective drought mitigation programs and guide policy planning at local and national levels to enhance the resilience of the agricultural sector against future climate extremes.
... Because differences in estimates of water scarcity can stem from all of these sources, the extent to which differences among indicators affect estimates of water scarcity is ambiguous. In the past, researchers have attempted to understand the individual influences of indicators, resolution, and environmental flows on water scarcity by reviewing previous works 9,22,23,[51][52][53][54][55] or by selecting a specific number of indicators at certain temporal and spatial resolutions 20,21,28,29 . Here, we disentangle the effects of different indicators, resolutions, and EFRs by using the same model and data to compare variation in estimates of water scarcity. ...
Water scarcity is a global challenge affecting billions of people worldwide. This study systematically assesses differences in the estimation of the global population exposed to water scarcity based on 7 water scarcity indicators and 11 Environmental Flow Requirements (EFR) evaluated at various spatial and temporal resolutions. All indicators show an increase in water scarcity since 1901. However, considering monthly average water scarcity estimates spatially aggregated at the basin scale found 35% less population exposed than estimates based on a distributed grid over the landscape. Estimates temporally disaggregated to consider water scarcity for at least one month a year found 50% (tenfold) larger population exposed compared to average monthly (annual) estimates. The study illustrates that estimates of the impacts of water scarcity are an artifact of how water scarcity is defined and calculated. This suggests caution is needed when relying on a single method and emphasizes the importance of considering the diversity of factors that can influence estimates of impact when assessing water scarcity.
... Irrigation-at-any-cost has been viewed as the answer to food security and agrarian livelihoods. But with burgeoning populations, urbanization, changing lifestyles and agricultural intensification, this approach proved unable to deal with absolute water scarcity in many parts of the world (Seckler et al., 1999;Jaeger et al., 2013). Climate change is all set to make matters worse (Hoff, 2011), signifying the limits of insular, infrastructure-based water governance (GWP, 2000;World Economic Forum, 2011;Shah, 2016). ...
This review explores the challenge of groundwater governance in Iran, Saudi Arabia, Mexico, China, Bangladesh, and India—which together account for over 2/3rd of the world’s groundwater use in irrigation. Global groundwater economy comprises three sub-economies: [a] diesel-powered unregulated, where use-specific energy subsidies are impractical; [b] electricity-powered regulated, where grid-connected electric tubewells are authorized, metered and subject to consumption-linked energy charges; and [c] electricity-powered unregulated, as in all geographies of our review --barring Bangladesh, Bengal and China-- where electricity subsidies have created an unruly, bloated groundwater economy. This last represents the heartland of global groundwater malgovernance, least prepared to meet the sustainability challenge.
In [a] and [b], groundwater scarcity stimulates water saving behavior via increased energy cost of pumping; not so in sub-economy [c]. This is home to water-energy-food-environment (WEFE) nexus at its most perverse since users are immune to energy cost and impervious to groundwater depletion. Nexus approach is prodigious in technical research but has ignored the realpolitik of groundwater reforms, especially in overcoming farmer resistance to legalizing and metering tubewells, and collecting energy-water charges based on metered use. Our review captures several workarounds to do this. A good example is a recent large pilot in Gujarat, India, which showcases how a smart transition to solar irrigation can transform a perverse WEFE nexus into a virtuous one, paving the way from [c] to [b]. During 2018-19, Gujarat solarized 4215 existing grid-connected tubewells of 5-150 horsepower, net-metered them and gave their owners a 25-year remunerative solar power purchase guarantee. Today: [a] all tubewells solarized are metered; [b] farmers willingly surrendered energy subsidy they enjoyed for decades; [c] most earn from ‘growing’ solar energy and selling their surplus; and [d] solar power feed-in-tariff acts as surrogate for water price. The pilot established preconditions necessary for proactive groundwater governance.
... Dynamic water pricing is an approach that accounts for water scarcity (Falkenmark and Lundqvist, 1998;Grey et al., 2013;Jaeger et al., 2013) and the intertemporal connections between present and future water use into current and future water prices (Dandy et al., 1984;Grafton et al., 2020). That is, the water price changes over time in response to a range of factors that influence both water demand (e.g., change in population) and water supply (e.g., droughts and floods). ...
This review examines key economic concepts in relation to the price and value of water for the supply and demand of household water. It responds to a series of questions about water and how it is used. These include (1) Why water is (or is not) priced and valued (or not)?; (2) What are the key economic concepts for pricing water?; (3) How is water priced and how are water supply assets valued for full cost recovery?; (4) Who bears the costs and enjoys the benefits of water use?; and (5) When is the price of water expected to change? Examples are provided to demonstrate the universality of the economic concepts while highlighting how their application must be bespoke and account for different socio-economic contexts and bio-physical conditions where water is supplied and demanded.
... Although these indices are valuable for improving our understanding of water scarcity, they focus on one aspect of water scarcity and do not reflect the sensitivity of water conditions to climate change, now recognized as the most important factor influencing water resources 20,21 . The uncertain effects of climate change on water scarcity have also raised concerns regarding the adequacy of current definitions of water scarcity 22,23 . Moreover, freshwater scarcity assessments also typically consider one-side classification schemes which do not represent important variations in social sensitivities and responses 23 . ...
Water scarcity has become a significant constraint to sustainable development. While the water scarcity has been widely assessed, its social impacts are infrequently evaluated. Here, we developed a framework to integrate the water scarcity and climate sensitivity to examine social vulnerability at the prefecture level across China. Results showed that 41% of the 301 prefectures were highly water stressed and 30% were highly sensitive to changing climate. We identified 44 hotspot prefectures using a combination of high water scarcity and climate sensitivity. We mapped the gradient in social vulnerability to water stress and climate sensitivity in these 44 prefectures and found that prefectures with ‘very high’ social vulnerability were primarily distributed in Central and Southwest China. These ‘very high’ vulnerable prefectures are home to more than 58 million people. The consideration of both water scarcity and climate sensitivity across management units has potential to formulate policies regarding water resources management.
... The primary reasons for water scarcity are climate changes, industrialization, contamination of limited freshwater supplies, deforestation, water pollution, and destruction of wetlands [5]. Due to a lack of safe freshwater, people in DZs are experiencing irrigation inefficiency, groundwater depletion and diseases such as dental fluoride, skin allergies, chronic kidney diseases, chronic renal failure, and skeleton fluorosis. ...
Water scarcity has already been recognised as a major 21st century global environmental problem [1]. Water scarcity arises when the demand for fresh water in a given domain exceeds the supply. Several nations are quickly depleting their freshwater supplies, and many large river basins in both developing and developed nations are experiencing severe water scarcity. According to Sri Lanka, the country is divided into two principal divisions based on annual precipitation of 1,875 mm: Dry Zones (DZ), which account for around 70% of the country, and wet zones, which account for the remaining 30% [2]. Sri Lanka’s DZ districts such as Ampara, Anuradhapura, Batticaloa, Kurunega¬la, Hambantota, Jaffna, Kilinochchi, Kurunegala, Mullaitivu, Polonnaruwa, Puttalam, Trincomalee, Mannar and Vavuniya are experiencing extreme seasonal or year-round water scarcity [3]. Water shortage is a common concern for residents of DZs during the dry season as a result of inadequate tank storage capabilities, maintenance and operation issues, and DZ population growth [4].
... These rising temperatures are anticipated to change the hydrological cycle globally (Wu et al. 2021a, b), ultimately impacting agricultural productivity and water demand and supply (Fooladi et al. 2021;Wu et al. 2021a, b;Sheffield and Wood 2008;IPCC 2022). The adaptability of people under water-scarce conditions defines the socioeconomic impacts of droughts at a given location (Jaeger et al. 2013). Globally, the agriculture sector consumes the majority of freshwater resources. ...
The agricultural water market (or water trade) is an effective water resource management tool to redistribute water from low-value to high-value agricultural farms. Water markets can play an important role in reducing the economic losses attributed to droughts by increasing flexibility in responding to water scarcity. Climate change has increased the scarcity and uncertainty of the agricultural water supply in the Mobile River Basin, mainly in Alabama, USA, which has imposed a huge risk to crop production in the region. In this study, agricultural water productivity is used to evaluate the value of irrigation water, and an analytical framework is developed to quantify potential economic efficiency gains within the river basin if water markets were to be implemented under future hydroclimate conditions. This approach circumvents the caveats of the traditional methods of estimating irrigation water demand. The results show that agricultural water markets can reduce the adverse impacts of climate change on the overall catchment-scale agricultural output in economic terms. The scenario approach presented in this study can provide preliminary estimates of the benefits of water trading, particularly in periods of drought and under future conditions of decreasing precipitation. The findings can aid in reducing the economic losses encountered by farmers under rainfed agricultural practices at a global scale.
... However, the search does not cover drought since it is considered a natural and transitory event [64]. Instead, the search considers the terms: water scarcity, water shortage, water stress, water crisis [7,[64][65][66], lack of water, dearth of water, or water penury [28,[67][68][69] and the possible variations of the semi-arid. ...
Water supply is strategic for the development of society. The water distribution in nature follows patterns linked to geographic and territorial issues. Climate fluctuations aggravate shortage problems in semi-arid regions. This study aims to develop a systematic review of research on water scarcity in semi-arid areas through bibliometric methods that allow the analysis of its structure, performance, evolution, and future trends. The methodology considers three phases: (i) literature review, (ii) data cleaning and processing, and (iii) analysis of the research field and future trends. The intellectual structure of water scarcity in semi-arid zones covers 2206 documents with the collaboration of sixty-one countries, distributed in studies carried out in 54 years (1967 to 2021). This field of research has been growing, especially since the 21st century (93.1% of the documents). The countries that study the issue the most are those with high population rates and large consumption patterns, such as the United States and China. There are two central areas of interest led by the terms "water scarcity" and "water stress" due to the intensive use of the resource for agriculture and the management of the water–energy–climate nexus. Thus, the most significant journals studied relate remote sensing to resource management, and the most cited are related to agriculture. This research made it possible to consider future topics such as the study of anthropogenic effects and climate change, the accuracy and applicability of models, and future trends in conventional and unconventional agriculture and resources.
... While these metrics are useful for understanding water stress geographically, they often do not adequately represent the temporal or quality-driven variations in water scarcity. They also often neglect to effectively communicate the human element-some incorporate population as a driver of demand, but population magnitude is rarely incorporated as a measure of impact (Jaeger et al., 2013). Measures that do incorporate population as a measure of impact, for example Worldwater.io, rely on a disaggregated Falkenmark indicator for their measures of water stress without considering water quality or policy, and aggregate population numbers for the public at the state level. ...
Latin America and the Caribbean (LAC) is the most water-rich region in the world, but millions of its inhabitants live with water risk. This contradiction, driven by mismatches in the location of supply vs demand, quality issues, and failing infrastructure, makes it crucial that policy makers use people-centric water risk metrics when assessing water risk in LAC. 35% of the population lives in water stressed basins, a number which balloons to 60% when accounting for the lack of institutional capacity for preserving water quality and providing water services.
... Our framework for linking water scarcity with incentives and investments focuses on the interaction of human and natural components of water (Srinivasan et al 2012, Jaeger et al 2013. We create this link using three steps: ...
Competition for freshwater resources is intensifying water scarcity and its impacts on people, economies, and the environment, posing a growing challenge for sustainable development. Meeting these challenges will require incentives to encourage sustainable water use. Prior calls to shift from supply-driven solutions to a soft path of demand management (pricing, markets, behavioral changes) have encountered stubborn obstacles. We undertake a multi-scale assessment of water reallocation and investment in water conservation technologies to understand their potential and limits for addressing different drivers of water scarcity. Our model identifies what drives water scarcity at the subbasin scale, and examines two prominent responses to these drivers. Our analysis distinguishes different types of water scarcity based on the demands for water and their timing, creating nine (9) categories of water competition, which can overlap. Water demand within agriculture contributes to scarcity in 94% of the basins experiencing scarcity, concentrated in central USA, Spain, and India. Urbanization has led to competition between cities and agriculture in 1,596 of 3,057 subbasins (52%). We examine how different institutional mechanisms (incentive-based water reallocation) and technologies (investment in water conservation technologies) can address these different types of water scarcity. This study builds on several local and high-resolution models demonstrating the potential to increase the economic efficiency (and marginal productivity) of water use. The gap between potential and implementation is high, however. Efforts to bridge this gap in priority geographies can link modelling advances with the design of pathways that combine incentives with robust water accounting, caps on water extraction, and enforcement capacity at multiple scales.
... by the timing and form of precipitation, and summer hydrology is governed by snowpack melt and groundwater discharge. Seasonal asynchrony between precipitation largely occurring during winter and summer water demand makes water supplies scarce and vulnerable (Jaeger et al., 2013). Climate models predict an exacerbation of this vulnerability Hamlet et al., 2010). ...
In mountainous river basins of the Pacific Northwest, climate models predict that winter warming will result in increased precipitation falling as rain and decreased snowpack. A detailed understanding of the spatial and temporal dynamics of water sources across river networks will help illuminate climate change impacts on river flow regimes. Because the stable isotopic composition of precipitation varies geographically, variation in surface water isotope ratios indicates the volume‐weighted integration of upstream source water. We measured the stable isotope ratios of surface water samples collected in the Snoqualmie River basin in western Washington over June and September 2017 and the 2018 water year. We used ordinary least squares regression and geostatistical Spatial Stream Network models to relate surface water isotope ratios to mean watershed elevation (MWE) across seasons. Geologic and discharge data was integrated with water isotopes to create a conceptual model of streamflow generation for the Snoqualmie River. We found that surface water stable isotope ratios were lowest in the spring and highest in the dry, Mediterranean summer, but related strongly to MWE throughout the year. Low isotope ratios in spring reflect the input of snowmelt into high elevation tributaries. High summer isotope ratios suggest that groundwater is sourced from low elevation areas and recharged by winter precipitation. Overall, our results suggest that baseflow in the Snoqualmie River may be resilient to predicted warming and subsequent changes to snowpack in the Pacific Northwest.
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... The global common and thorny issue of water shortage and pollution has restricted the development of social and regional economic development (Jaeger et al. 2013, Hanasaki et al. 2013. The concentration and form of chemical compositions have a significant influence on the water quantity and quality, and also play an important role to ensure ecological environment and regional economic development (Ayadi et al. 2018). ...
... To achieve the goal of urban water conservation, it is important to improve water production capacity and reduce water loss in production and transportation through the construction of water resource-use infrastructure [57,58], such as urban water source protection projects, water purification and storage facilities and water transportation pipelines. As water scarcity variation has mainly been related to the properties of water and its role in natural-human systems [59], attention should also be paid to scientific incentive mechanisms for urban water-use through the innovation and promotion of water-use technologies [60], rights transactions [61], pricing [62,63], and the cultivation of water-saving awareness [9]. It is undoubted that the water-saving society policy in China can effectively reduce water consumption per CNY 10,000 GDP, as mentioned above, by increasing water-saving investments and developing water-saving behaviors. ...
The increased demand for water resources due to urban population and economic growth has worsened the urban water crisis. In order to address this issue, a policy of “developing a water-saving society” (namely, water-saving society policy) has been implemented in some Chinese cities. This study takes 285 cities at the prefecture level and above as the sample and uses the propensity score matching (PSM) method to analyze the effect of China’s urban water-saving society policy on the reduction of water consumption per CNY 10,000 gross domestic product (GDP) from 2005 to 2017. The results show that the water-saving society policy significantly (p < 0.01) reduced water consumption in the study period; however, the effects differed between cities with different water resource endowments, economic development level, and urban scale. Specifically, there was a positive water consumption reduction effect in cities in humid areas, with low economic development, or of large scale, while the effect was limited in cities in arid areas, with high economic development, or of small scale. Therefore, for areas where water resource supply is insufficient, water-saving policy should be designed and implemented suiting local conditions, and it is also necessary to explore more water sources.
... In many countries, policy-makers face the dilemma of how to respond to increasing physical water scarcity-the decline in water supply per capita (Falkenmark et al., 1989;Jaeger et al., 2013). The traditional focus on supply-based 'solutions' to water scarcity and investing only in water supply infrastructure is an insufficient response to the demand-and supply-side causes of water scarcity (Grafton, 2017). ...
We deliver a public policy perspective on the dichotomies, dilemmas, and decisions of water pricing. First, the dichotomies between price and value, and costs, are defined to explain the paradox of water pricing: the price of water almost never equals its value and rarely covers its cost. Second, the dilemmas of water pricing are highlighted across efficiency and equity, objectives for water pricing, and the instruments available to decision-makers. Third, the challenges of decision-making are evaluated and illustrated in relation to water pricing. Fourth, an adaptive process is provided that includes participatory assessment of risks and options to guide water-pricing decision-making.
... Generally, there is a growing consensus on the importance of effective and efficient water institutions for proper water governance, fair utilization, and achieve water security (Bandaragoda, 2000;Bruns & Meinzen-Dick, 2005;Hagedorn, 2008;Ingram et al., 1984;Jaeger et al., 2013;Kemper et al., 2005;Ostrom, 1990;Saleth & Dinar, 2004. Nonetheless, the available water security measure as monitoring tools are not tailored to local context and failed to address the issue of institutions at household level. ...
Despite water security becomes a complex global challenge; its assessments are spatially and temporally inconsistent. This affected water security monitoring at the local level. Some studies attempted to downscale national, regional or global level indicators to local scale, which have several shortcomings. Therefore, this study came up with a new household water security Index to estimate the state of water security at a local level. The study constructed Household Water Security Index (HWSI) based on water resources availability (R), access (A), utilization (U), capacity (C), and environment (E), and water institution (I) indicators. It also tested the index using a sample district in the Awash Basin of Ethiopia. A cross-sectional firsthand data were collected from randomly selected 400 households. A multivariate technique called Principal Component Analysis (PCA) and bivariate correlation were employed. The result revealed that every household is either chronically or transitionally water unsecured. This was mainly due to poorly organized institutions, as well as lack of both the system and knowledge of water management systems under scarcity and surfeit. In some areas, there are moderate resource constraints. In other areas, the capacity to use water is very low. Yet the institutional performance was consistently weak. We concluded that first; macro-level indicators often obscure the local realities. Thus, the policy-makers and development planners need to prioritize the household’s situations accordingly. Second, water resources availability with proper use and capacity plays a pivotal role to achieve household water security. Third, it is important to integrate institutional elements in water security as a mediating process and stewardship of the local needs. Fourth, the HWSI can be replicable at various scales and contexts, which could be considered for further research. Finally, recognizing the local arrangements and building the capacity of water actors are of paramount importance.
... Local climate and the evolution of droughts will vary with location. Water scarcity is due not only to lack of rain, but also due to human actions (Jaeger et al. 2013). The scarcity of water in a region must be understood in the spatial and temporal context. ...
During the 2012–2016 drought in La Guajira, Colombia, child mortality rates rose to 23.4 out of 1000. Most of these children belonged to the Wayuu indigenous community, the largest and one of the most vulnerable in Colombia. At the municipal level, this study found a significant positive correlation between the average child mortality rate and households with a monthly income of less than USD 100, the number of people without access to health insurance, being part of the indigenous population, being illiterate, lacking sewage systems, living in rural areas, and large households with members younger than 5 years old and older than 65 years old. No correlation was found with households without access to a water source. The stepwise regression analysis showed that households with a monthly income of less than USD 100, no members older than 65 years old, but several children younger than 5 years old, account for 90.4% of the child mortality rate. This study concludes that, if inhabitants had had better incomes or assets, as well as an adequate infrastructure, they could have faced the drought without the observed increase in child mortality.
... This has twin effects of increasing the supply of useable water, and decreasing the demand for potable water. That is, water reuse allows us to take into account the marginal value of water (Gaudin, 2006;Jaeger et al., 2013). Moreover, in terms of safety, the recycling of used water has been found to be one of the safest options, both as a potable and nonpotable water source (Miller, 2006;Huertas et al., 2008;Rodriguez et al., 2009;Blandin et al., 2015). ...
Of the 17 SDGS, the United Nations has recently revealed that countries are not on track to receive the water and sanitation goals by the deadline. As climatic events decrease the reliability of traditional drinking sources, especially in cities, recycled drinking water (RDW) is becoming an increasingly important policy option. Yet, the implementation of RDW remains mired in difficulties, with the psychological “yuck” factor as a key obstacle. Studies of successful cases of RDW implementation show that trust, information and social norms are important. However, no studies of RDW have directly compared the relative importance of information to the power of social norms. This paper explores the role of conformity, as a social norm, in increasing public acceptance of recycled water for drinking. Using a simple choice experiment, we find that conformity per se appears to provide sufficient reason for behavioural change relating to recycled water, rather than information or economic incentives. This study is one of the first to present empirical evidence from a choice experiment on RDW, and has practical implications on the use of conformity as motivation to taking difficult decisions.
... Changes at one ecologically important threshold can result in a range of interrelated impacts to the system. For example, maintaining forest moisture above biophysical thresholds minimizes system vulnerability to forest fires, disease, and other disturbances that can lead to downstream impacts to populations (Jaeger et al., 2013). Trends at precipitation thresholds for these various contexts may also depart from mean trends, further underscoring the need for flexible approaches to characterize precipitation variability and change ...
Water management approaches have historically optimized water for human use and placed lower emphasis on the relationship between ecosystems and humans. Despite efforts to balance human and ecosystem needs, existing management approaches tend to prioritize some needs, knowledges, and values over others. Natural and anthropogenic changes pose challenges to water governance institutions due to policy inflexibility, and may lead to ecosystem degradation, water stress, and conflict among water users. This work seeks to redress these shortcomings through three scholarly contributions. First, a conceptual framework for Water Resources Stewardship is developed in support of equitable and adaptive solutions under changing conditions. Key elements include attention to the structure of governance, opportunities for stakeholder inclusion, knowledge production and use, and adapting to changes in risk. A meta-analysis of prominent water sector approaches identifies gaps and informs future perspectives. Next, a historical analysis of Maine’s in-stream flow policy is presented. The analysis approach comprises of a) delineation of the rulemaking structure including the sequence and co-evolution of processes therein, b) characterization of events and conditions leading to rulemaking, and c) identification of opportunities and constraints to integrate adaptive policymaking in a water use context undergoing change. Opportunities for learning, integration of diverse stakeholder needs, and infusion of knowledge are needed to enable adaptive processes. Lastly, methodological advancements for assessing precipitation change enables a reassessment of risk to human and ecological systems. A quantile regression approach is used to a) assess annual precipitation relationships with oceanic indices at river basin scales, and b) identify asymmetries with mean precipitation trends at the global scale. Notably, significant land area and populations are overlooked by conventional methods. An extension to rainfed agriculture underscores the need for more accurate appraisal of change and uptake into risk management approaches.
... At no point do the authors mention that the measure of water scarcity is really a measure of risk to water supplies from both climatological and demographic stressors; they mention only WSSI's climatological aspects. It is reasonable to consider both the demand side and supply side of water use when it comes to evaluating urban water rates, especially since many definitions of "water scarcity" do consider both supply and demand side factors (Jaeger et al., 2013). Luby et al.'s title and rhetoric, however, suggest only the supply side. ...
In a recent article in this journal, Luby, Polasky, and Swackhamer come to the provocative conclusion that urban water prices in the United States are “cheaper when drier.” They also argue that utilities fail to provide affordable water and that they charge less for “additional” use compared to “essential” use. We challenge these claims. While the authors correctly point out the many challenges that utilities face in supplying affordable water while meeting conservation and revenue goals, there are serious flaws in their measures of price, scarcity, and affordability. These measurement problems lead the authors to incorrect conclusions about water pricing in the United States. Using improved measures of price and water scarcity, we find little statistical relationship between the marginal price of water/sewer services and scarcity. Our findings cast doubt on Luby et al.'s findings and point to important avenues for future research.
... So, in fact, the title probably should have been "U.S. urban water bills: Cheaper when scarcer" (though this does not have the same poetic ring to it). We also agree that there is value in using improved measures, for example, better measure of scarcity (Jaeger et al., 2013), and larger samples. We would welcome additional studies along these lines. ...
Key Points
The Palmer Drought Severity Index (PDSI) is not an appropriate measure of water scarcity
Using our preferred metric, we find that water rates, both in terms of total bills and marginal prices, are cheaper where water is scarcer
Switzer and Teodoro have misinterpreted our Key Point 3; average prices can decline while marginal prices increase with greater water use
... Around two-thirds of the global population are now living in conditions of severe water scarcity for at least one month of the year, and half a billion people face severe water scarcity all year round (Mekonnen and Hoekstra, 2016). Moreover, water scarcity in many parts of the world tends to increase (Rosegrant et al., 2009;Jaeger et al., 2013;Hejazi et al., 2014;Hoekstra, 2014). "To reduce the number of people suffering from water scarcity"is one of the 17 targets in Sustainable Development Goals set by the United Nations (2015), and is also high on the policy agendas of many state and local governments. ...
Both population-driven and demand-driven water scarcity levels are analyzed. • Structural decomposition analysis is used for water scarcity analysis. • Temporal water scarcity changes in Bei-jing contain a trend and randomness. • Hydro-climatic factor dominates water scarcity change in consecutive years. • Declining demand-driven water scarcity is attributed to socioeconomic factors. Editor: Ralf Ludwig Water scarcity has become a serious problem in many parts of the world. While many previous studies have recognized that the changing water scarcity levels were attributed to population growth, economic development and climate change, effects of different factors on variations of water scarcity were rarely disentangled and quantified based on historical data. This study develops an analytical framework, based on the structural decomposition analysis, to decompose temporal water scarcity changes into effects of a number of hydro-climatic and socioeconomic factors. The methodology is applied to water scarcity analysis in Beijing, China, which has long been under severe water scarcity. Results from Beijing show that the population-driven water scarcity tends to increase, whereas the demand-driven water scarcity presents a slightly declining trend. The declining trend of demand-driven water scarcity is mainly attributed to industrial structure upgrade, improved water use efficiency , reclaimed and transferred water uses, and domestic water saving. In contrast, the economic development, population growth and increased ecological water use contribute to aggravating Beijing's water scarcity. High randomness in Beijing's water scarcity is mainly attributed to variability of available water resources. The results provide an in-depth understanding of dynamics in water demand and supply, and help develop policies towards sustainable water resources planning and management.
... While social water scarcity also highlights important challenges, we focus on physical water scarcity as a first step to examine water shortage, especially increasing population, shifting lifestyles and changing climate are predicted to considerably increase challenges of water accessibility within the following decades (Alcamo et al. 2003). Physical water scarcity has been used to evaluate future water availability at national and regional scales (Jaeger et al. 2013). This study highlights analysis and decision making for water scarcity at a regional scale and enable estimation of water pricing. ...
Water management is one of the main issues in the water policy agenda. More than a quarter of the world's population will experience severe water scarcity. Although there is board agreement on the importance of incorporating the concept of scarcity into water-management strategies and decision making, the lack of a standardized approach to embedding water scarcity has hindered progress in this direction. In recent years, pricing household water has been proposed as a tool for managing water scarcity in a national context. The objective of this work is to design a water-pricing model that better signals the value of water scarcity by considering water supply and demand at the same time. The proposed scarcity-based pricing model focuses on the variable component of the tariff and follows an increasing block strategy. The case study of the Taipei Water Resource Domain (Taiwan) is used to illustrate the method. It is Greater Taipei’s main source of fresh water. By calculating the supply, demand, and budget of water resources in northern Taiwan, this study also determines the visible spatial distribution of water scarcity. The results show that both the supply and demand of water resources changed considerably under three scenarios, namely, low rainfall, average rainfall, and extreme rainfall. This demonstration illustrates a pathway for the implementation of a proposed scarcity-based pricing policy as a signal for users to adjust their water consumption in a proactive manner.
... Additionally, these are point-based measurements at stationary locations-functioning in a non-stationary climate. Since the availability and scarcity of water vary in time and space [14], the ability to better understand and quantify the accumulation and melt of mountain snowpack would advance science and improve the capacity for better-informed water resource management. ...
We tested the efficacy and skill of SnowCloud, a prototype web-based, cloud-computing framework for snow mapping and hydrologic modeling. SnowCloud is the overarching framework that functions within the Google Earth Engine cloud-computing environment. SnowCloudMetrics is a sub-component of SnowCloud that provides users with spatially and temporally composited snow cover information in an easy-to-use format. SnowCloudHydro is a simple spreadsheet-based model that uses Snow Cover Frequency (SCF) output from SnowCloudMetrics as a key model input. In this application, SnowCloudMetrics rapidly converts NASA’s Moderate Resolution Imaging Spectroradiometer (MODIS) daily snow cover product (MOD10A1) into a monthly snow cover frequency for a user-specified watershed area. SnowCloudHydro uses SCF and prior monthly streamflow to forecast streamflow for the subsequent month. We tested the skill of SnowCloudHydro in three snow-dominated headwaters that represent a range of precipitation/snowmelt runoff categories: the Río Elqui in Northern Chile; the John Day River, in the Northwestern United States; and the Río Aragón in Northern Spain. The skill of the SnowCloudHydro model directly corresponded to snowpack contributions to streamflow. Watersheds with proportionately more snowmelt than rain provided better results (R2 values: 0.88, 0.52, and 0.22, respectively). To test the user experience of SnowCloud, we provided the tools and tutorials in English and Spanish to water resource managers in Chile, Spain, and the United States. Participants assessed their user experience, which was generally very positive. While these initial results focus on SnowCloud, they outline methods for developing cloud-based tools that can function effectively across cultures and languages. Our approach also addresses the primary challenges of science-based computing; human resource limitations, infrastructure costs, and expensive proprietary software. These challenges are particularly problematic in countries where scientific and computational resources are underdeveloped.
... More general terms, such as risk, scarcity or uncertainty, might be more obviously prone to this problem, since a greater number of sub-communities using a particular term means a greater potential for a drift into ambiguity or polysemy -when a word has several, related senses (Nunberg, 1979). These general terms have received attention in writings such as by Jaeger et al. (2013) who constructed a formal definition of the word scarcity in a hydrological setting, McVicar & Körner (2013) who addressed the use of the terms altitude, elevation, and height, Meylan et al. (2012) who elaborated on the different meanings of the term risk, and Refsgaard & Henriksen (2004) and Beven & Young (2013), who made suggestions for the use of modelling terms. ...
In scientific communication, ambiguities in term usage can go unnoticed due not only to the distance between reader and writer, but also to the existence of highly specialized scientific subcommunities. This commentary therefore aims at raising awareness about the use of terms that have different meanings within different hydrological subcommunities such as field hydrology, hydrological modelling, or statistical hydrology. To do so, we discuss the use of the following commonly used hydrological terms: sample, runoff, discharge, and streamflow. We performed three types of analyses to provide evidence of term usage and understanding, including both qualitative and quantitative approaches: a drawing exercise, a survey, and a literature corpus analysis. These analyses allow for a comparison of spontaneous definitions and the actual use of these terms in scientific publications. Our various information sources revealed that the dialogue between hydrologists within and across subdisciplines is substantially influenced by personal conceptualizations of terms that are not always shared across conversational partners. The terms discussed and illustrated in this commentary have to be seen as a small sample used to demonstrate the need for a thoughtful use of hydrological terms when communicating research, not only to a general audience, but even across subdisciplines within hydrology.
... The causal relationship between these conflicts and water scarcity is not straightforward. Water scarcity is an anthropocentric concept that reflects human preference values, and thus needs to be differentiated from the purely hydrologic concept of water deficit [21]. Water scarcity is defined as an imbalance between supply and demand of freshwater in a specified domain (country, region, catchment, river basin, etc.) as a result of a high rate of demand compared with available supply, under prevailing institutional arrangements and infrastructural conditions [22] (p. ...
The Cochabamba Water War (2000) is well renowned for being a part of the civil society versus water service delivery debate. From a situation of service privatization, limited access, and an inexistent institutional framework in 2000, the current situation in the Cochabamba Valley faces increasing water scarcity within a weak institutional set up. To alleviate the situation, the government of Evo Morales has been actively funding projects considering an Integrated Water Resources Management (IWRM) but confronting customary water rights in rural communities and thus increasing the level of conflict between water uses. Amid these two water management practices appears the Agenda del Agua Cochabamba (AdA)—the Cochabamba Water Agenda—claiming water as part of the commons and not a resource. This paper explains the paradigm’s values behind the conflicting IWRM and water rights’ water management practices and analyses the AdA under a governability framework identifying the barriers and drivers for its implementation.
... The research results show that the availability of water sources that can meet human needs in quantity and quality are more and more difficult to find. Moreover, many regions of the world wide have experienced droughts and water scarcity [22,23,24,25]. Since water resources are a vital need for all humans and other living beings, this paper will examine the development of the concept of carrying capacity in the water sector. ...
The concept of carrying capacity is widely used in various sectors as a management tool for sustainable development processes. This idea has also been applied in watershed or basin scale. Bandung Basin is the upstream of Citarum watershed known as one of the national strategic areas. This area has developed into a metropolitan area loaded with various environmental problems. Therefore, research that is related to environmental carrying capacity in this area becomes a strategic issue. However, research on environmental carrying capacity that has been done in this area is still partial either in water balance terminology, land suitability, ecological footprint, or balance of supply and demand of resources. This paper describes the application of the concept of integrated environmental carrying capacity in order to overcome the increasing complexity and dynamic environmental problems. The sector that becomes the focus of attention is the issue of water resources. The approach method to be carried out is to combine the concept of maximum balance and system dynamics. The dynamics of the proposed system is the ecological dynamics and population that cannot be separated from one another as a unity of the Bandung Basin ecosystem.
Water scarcity and its geopolitical implications have been a cornerstone of scholarly discourse. However, literature often overlooks the nuanced relationship between human traits and water management. Addressing this oversight, this study synthesized data from 149 articles (1991–2023), revealing a substantial connection between human actions and water management dynamics. From this data, a unique comprehensive framework was developed, focusing on the intricate interplay of human behaviors, leadership dynamics, economic factors, and technological advancements in water management. Unlike previous works, this framework holistically integrates these components, offering a fresh lens through which to understand the human-centric factors underpinning global water scarcity. This study underscores the framework’s vital role in guiding sustainable water management and strategy, making it an indispensable tool for stakeholders, from policymakers to environmentalists. In essence, this research not only bridges a knowledge gap but also serves as a beacon for addressing pressing water scarcity challenges in today’s world.
Water consumption grew twice as fast as the global population last century, and an increasing number of regions around the world are facing or will face, water scarcity. Access to water has been recognized as a major threat to world peace in the present century, and ethical issues related to water have been given high priority. Using a systematic review method, this paper examines the three fundamental perspectives of deontology, con-sequentialism, and virtue ethics in environmental philosophy and their implications for water management and policy-making. Each of the three perspectives has led to the emergence of different ethical approaches to water, but what is clear is that in all three perspectives anthropocentric view has prevailed and moral considerations about non-humans have received less attention. In addition, ethical approaches to water face weaknesses , and water management requires an integrated and holistic approach that integrates humans and aquatic ecosystems and avoids unilateralism.
Many cities around the globe have recently started experiencing urban flooding. Floods bring untold miseries to the urban dwellers for whom the flooding is an unexpected phenomenon in their city. Cities like Nagpur where the issue of flooding has become serious over the last few years due to extensive alteration in the natural systems are searching for solutions to this situation.
Integrated approach for stormwater management is an approach implemented in many places is known to have successfully manage the water bodies in the city. It tries to look at the excessive rains that cause urban floods as a solution to the water scarcity issue faced by the city. This study aims to apply such an approach to Nagpur and create a systematic framework to understand which areas are more likely to get flooded. It also assesses which interventions need to be made at different spatial scales to avert it.
The study tries to use the SCS method and software like ArcGIS, ArcSWAT, HydrCAD, and AutoCAD in combination to create the framework for similar cities, especially in Central India. An attempt to use data readily available for most of the major Indian cities is done so that the framework is easy to use. Proposals and measures have been suggested for specific areas which were found to be flood prone in the analysis. Ultimately, the implementation mechanism of each of the proposals and their benefits has been suggested.
Human demand for adequate water resources and supplies has been and will continue to be a fundamental issue in the 21st century due to rapid population growth, growing economies and globalization, and increasing water pollution, among others. Water withdrawals in regions which are already encountering scarcity will impose intensifying pressure on water resources locally and globally, threatening the achievement of long-term sustainable development targets. Decoupling has increasingly been recognized and incorporated in policy making as a way to reconcile limitless economic growth with environmental pressures. Filling evident literature gaps, the current state and projected future decoupling factors of water withdrawals in relation to GDP are assessed through decoupling and regression analyses for 155 countries and 12 potential socioeconomic development pathway scenarios. Findings suggest that average levels of water withdrawal decoupling are moderate in 2025 but will increase throughout the century in all countries. By 2075, average water withdrawal decoupling becomes common and widespread, with high decoupling factors across the world. Yet, some countries and regions will continue to lag behind in this development. GDP growth is the most significant driver of water withdrawals. Climate and regional differences among countries are major influential factors on decoupling outcomes, more so than current country-level income group classification. Altogether, these results are of high significance to water resource managers and policy actors, offering a chance to act proactively to change the course on global water resource and country-specific development. In this way, decoupling provides a pathway to a more water-wise world.
En climat méditerranéen, l’évapotranspiration potentielle est forte, en particulier durant la saison estivale. Elle coïncide avec une période de faible pluviosité. Si celle-ci perdure durant des phases de forte évapotranspiration, elle peut avoir de graves conséquences sur les activités agricoles très consommatrices en eau pendant leur période de croissance. Une étude de la sécheresse atmosphérique dans le secteur du Gardon est réalisée à partir de l’indicateur des séquences sèches. Premièrement, une étude historique permet d’identifier les grands évènements de sécheresse dans le bassin du Gardon entre 1900 et 2019. Puis une analyse sur l’effet du seuil de pluie pour caractériser les précipitations utiles est proposée. Différentes définitions du jour sec sont testées pour calculer les séquences sèches entre 2000 et 2019. L’utilisation d’un seuil d’évapotranspiration réelle ou d’évapotranspiration potentielle, par rapport à un seuil de 1 mm, modifie à probabilité d’occurrence égale la saisonnalité et la géographie de l’intensité des séquences sèches. Les seuils d’évapotranspiration réelle et d’évapotranspiration potentielle produisent des évènements plus intenses qu’un seuil de 1 mm. L’intensité des séquences sèches est sous-estimée avec un seuil de 1 mm pour les évènements des mois de printemps mais surtout pour ceux de début d’été. Sont identifiés à risque, quel que soit le seuil retenu, les secteurs du sous-bassin de la Salindrenque et la partie la plus aval du bassin du Gardon. Elles sont touchées à probabilité d’occurrence égale par des intensités plus importantes pour les évènements de moyenne et de forte intensité que le reste du bassin. La comparaison des distributions statistiques en fonction du seuil retenu montre que, à défaut d’avoir une valeur d’évapotranspiration réelle pour déterminer les précipitations utiles, le seuil 1 mm reste plus pertinent qu’un seuil d’évapotranspiration potentiel.
This report explores some of the thorniest water crises taking place across the developing world. In southern Iraq, severe water quality problems have triggered social unrest and violent protests. Recent droughts in India have prompted an exodus of farmers from the countryside in Maharashtra and dried up the reservoirs serving the city of Chennai. Across the African Sahel, there are violent conflicts between farmers and pastoralists over water and productive land resources. In Yemen, urban water systems have been targets of persistent attacks during the ongoing conflict in the country. Drawing on the report’s six in-depth case studies — from Iraq, Iran, India, the African Sahel, Central America and Yemen — as well as other recent research, the authors identify strategies to reduce water-related security risks. These solutions are organized into four broad categories: natural resources, science and engineering approaches; political and legal tools; economic and financial tools; and policy and governance strategies. The framework presented in this report provides decision-makers with options for tailoring solution sets to unique water challenges. It is intended for global development, diplomacy, defense and disaster response experts, as well as for national- and river basin-level decision-makers charged with addressing natural resource–based conflict, migration and other forms of insecurity. This report is research for action. It provides the evidence, examples and solution-oriented analysis that decision-makers need to avert water crises around the world. As the costs of inaction rise, policymakers should work to overcome barriers to implementation by increasing political will and recognizing the benefits of improved water resources management, drought response, flood prevention and access to safe, reliable and affordable water for all.
Drought and Water scarcity: I love you neither I
This paper deals with a clarification of the two words used to characterize an abnormal lack of water due to natural factors : drought and water scarcity. First, it questions the definitions and causes of a drought. Then, it shows why a partitioning of natural and anthropogenic causes in the construction of the dualism drought / water scarcity testifies to the influence of epistemological heritages. But it is not particularly relevant in the contemporaneous context. Finally, the paper demonstrates that droughts considered as environmental risks are hybrid objects. They imply to adopt a vulnerability approach in order to better analyze situations of abnormal lack of water.
Violence over water resources has persisted in various forms for thousands of years, driven by complex ideological, religious, economic, and strategic factors. Scarce and valuable freshwater has played a role in conflicts as a contributing factor, a target or tool, or a weapon. The focus of this review is on specific instances of violence around water and water systems conflict in Syria, Iraq, and Yemen, where water resources and human‐built water systems have been both weapons and targets of conflict. A new cycle of violence in the region, growing in extent and severity, began approximately three decades ago and is described here in the context of broader regional water challenges and theoretical issues around environmental security. New data and definitions and an analysis of the types of event and sources of information are also provided in the context of international humanitarian law. This assessment confirms and expands upon previous work that evaluates trends toward the weaponization of water and the targeting of water systems in Middle East conflicts. Initial recommendations for reducing these trends are provided.
This article is categorized under:
• Human Water > Water Governance
• Human Water > Rights to Water
• Science of Water > Water Quality
Abstract Numerous human and environmental systems are sensitive to the spatial and temporal distribution of precipitation, including agriculture, water supply, and ecosystems. Trends in observed precipitation form an important line of evidence to understand how changes may increase system vulnerabilities. Linear trends reported in US and global climate assessments reflect changes in mean annual precipitation. Mean trends may not reflect changes across other quantiles in the precipitation probability distribution, including the tails (very high and low precipitation levels), leading to systematic mischaracterization of climate risk. Here we reanalyze global annual precipitation using quantile regression to reveal overlooked trends. We find trends in the tails inconsistent with the mean in 44.4% of land area and 40.7% of rainfed agricultural regions. Previously undetected trends offer a more accurate view of the changing climate. This work enables reappraisals of risk aggregated over thresholds in human and environmental systems, enabling revaluation of threats and identification of appropriate adaptation strategies.
Few international water-sharing agreements have shown the flexibility to adjust to extended drought; fewer still
provide safeguards for adaptation to modern climate variability. Yet, current conflicts over the development and
use of transboundary rivers continue to motivate the search for negotiated water-sharing arrangements that can
provide flexibility in the face of change. To avoid future conflicts, an agreement must include measures that
allow for adaptation to changes in water supplies, population, climate, technology, infrastructure, and economic
activity while also guiding water use patterns. The benefits of a flexible agreement can be a more predictable
water supply for all riparians, greater incentives to develop needed water infrastructure and more open, transparent
and accountable water institutions. Other benefits include increased food production, water security, environmental
protection, reduced flood damage, better adaptation to the costs of extreme weather and variable
climate, and a reduced need for complex legal, administrative and enforcement activities. This paper investigates
ways to achieve sustainable transboundary water-sharing agreements. It investigates barriers to forging water-sharing
agreements, describes errors that could undermine settlements and presents takeaway lessons from two North
American agreements and one in south Asia. Finally, the paper proposes an approach by which information on
headwater flows and historical use patterns could be used to allocate supplies between riparians that adapt to
changes in water supply and demand. Outcomes from the implementation of structured, but flexible agreements
could help guide future negotiated settlements for the worlds international rivers.
This paper reviews recent developments in cost–benefit analysis for water policy researchers who wish to under-stand the applications of economic principles to inform emerging water policy debates. The cost–benefit framework can provide a comparison of total economic gains and losses resulting from a proposed water policy. Cost–benefit analysis can provide decision-makers with a comparison of the impacts of two or more water policy options using methods that are grounded in time-tested economic principles. Economic efficiency, measured as the difference between added benefits and added costs, can inform water managers and the public of the economic impacts of water programs to address peace, development, health, the environment, climate and poverty. Faced by limited resources, cost–benefit analysis can inform policy choices by summarizing trade-offs involved in designing, applying, or reviewing a wide range of water programs. The data required to con-duct a cost–benefit analysis are often poor but the steps needed to carry out that analysis require posing the right questions.
Our aim in this essay is to identify and analyze some of the difficulties with
interdisciplinary integration of economic and ecological contributions to the study of
biodiversity loss. We develop our analysis from a widely accepted definition of economics
which is based on the concept of scarcity. Taking a closer look at this notion, we find that
economics actually limits itself to a very particular aspect of scarcity, which we denote as
relative scarcity. We describe in what respect the economic approach towards biodiversity is
based on this notion, and also reflect on the specific understanding of the relation of humans
and nature behind the economic approach. We then turn to absolute scarcity as another notion
of scarcity, and show that this is not within the scope of economics, but has been a theme of
ecology and ecological economics. We describe in which way ecological and ecological-
economic approaches towards biodiversity are based on the idea of absolute scarcity, and also
reflect on the specific understanding of the human-nature relationship behind this notion of
scarcity. Against this background, we discuss the roles of economics and ecology for nature
conservation. We conclude that the interdisciplinary integration of ecology and economics
requires a philosophical underpinning, and suggest a framework for further research.
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Water management in the Pirapama River Basin in northeastern Brazil is affected by both water quantity and water quality
constraints. The region is known for significant sugarcane-based ethanol production—which is the key to the Brazilian economy and
expected to grow dramatically under recent changes in climate and energy policies. Sugarcane production in the region goes hand in hand
with controlled fertirrigation practices with potentially significant adverse impacts on the environment. To assess sustainable water
allocation in the basin, an integrated hydrologic-economic basin model is adapted to study both water quantity and quality aspects. The
model results show that incorporating water quality aspects into water allocation decisions leads to a substantial reduction in application
of vinasse to sugarcane fields. Embedding highly nonlinear water quality constraints in a basin optimization model is demonstrated to be
an effective tool to address the water management problems in rapidly developing biofuel areas of Brazil and elsewhere.
Freshwater scarcity has been cited as the major crisis of the 21st
century, but it is surprisingly hard to describe the nature of the
global water crisis. We conducted a meta-analysis of 22 coupled
human-water system case studies, using qualitative comparison analysis
(QCA) to identify water resource system outcomes and the factors that
drive them. The cases exhibited different outcomes for human wellbeing
that could be grouped into a six "syndromes": groundwater depletion,
ecological destruction, drought-driven conflicts, unmet subsistence
needs, resource capture by elite, and water reallocation to nature. For
syndromes that were not successful adaptations, three characteristics
gave cause for concern: (1) unsustainability—a decline in the
water stock or ecosystem function that could result in a long-term steep
decline in future human wellbeing; (2) vulnerability—high
variability in water resource availability combined with inadequate
coping capacity, leading to temporary drops in human wellbeing; (3)
chronic scarcity—persistent inadequate access and hence low
conditions of human wellbeing. All syndromes could be explained by a
limited set of causal factors that fell into four categories: demand
changes, supply changes, governance systems, and
infrastructure/technology. By considering basins as members of syndrome
classes and tracing common causal pathways of water crises, water
resource analysts and planners might develop improved water policies
aimed at reducing vulnerability, inequity, and unsustainability of
freshwater systems.
We investigated the relative importance of future climate change and land use change in determining the quantity and quality of freshwater resources in northwestern Oregon's Tualatin River Basin using the U.S. Environmental Protection Agency's Better Assessment Science Integrating Point and Nonpoint Sources (BASINS) modeling system. Models were calibrated and validated using historic flow and water quality data between 1990 and 2006. The goodness of fit for the calibrated models was high, with coefficients of determination ranging from 0.72 to 0.93 in the calibration period. The calibrated models were run under a range of eight statistically downscaled climate change, two regional land use change, and four combined scenarios. Results included average increases in winter flows of 10 percent, decreases in summer flows of 37 percent, and increases in fifth-percentile flows of up to 80 percent as a result of climate change in the Tualatin River Basin. For land use change, the results included an increase in annual flows of 21 percent for the development-oriented scenario and a decrease of 16 percent for the conservation-oriented scenario. For combined scenarios of high climate change and high urban development, there is a projected increase in winter flows of up to 71 percent and decrease in summer flows of up to 48 percent. Climate change scenarios were more significant than urban development scenarios in determining basin hydrological response. The results are relevant to regional planners interested in the long-term response of water resources to climate change and land use change at the basin scale.
Vulnerability is the degree to which a system or unit is likely to expierence harm due to exposure to perturbations or stress. The vulnerability concept emerged from the recognition that a focus on perturbations alone was insufficient for understanding responses of and impacts on the peoples, ecosystems, and places exposed to such perturbations. With vulnerability, it became clear that the ability of a system to attenuate stresses or cope with consequences constituted an important determinant of system response, and ultimately, of system impact. While vulnerability can expand our ability to understand how harm to people and ecosystems emerges and how it can be reduced, to date vulnerability itself has been conceptually hampered. It tends to address single stresses or perturbations on a system, pays inadequate attention to the full range of conditions that may render the system sensitive to perturbations or permit it to cope, accords short shrift to how exposed systems themselves may act to amplify, attenuate, or even create stresses, and does not emphasize the importance of human-environment interactions when defining the system exposed to stresses. An extended framework for vulnerability designed to meet these needs is emerging from a joint research team at Clark University, the Stockholm Environment Institute, Harvard University, and Stanford University, of which several authors on this paper are part. This paper is a first attempt to explore the utility of this extended vulnerability framework, by conducting a preliminary application of it to three global coastal cities with regard to their vulnerabilities to climate hazards. While this new framework needs further refinement and testing, and some methodological obstacles remain, our research suggests there is benefit from using the extended framework to guide assessments of vulnerability. The framework illuminated further system characteristics that, in unique combinations, create place-based vulnerabilities to climate hazards. The framework's complexity, however, required us to conduct outside the framework several analyses comparing bundles of stresses to which the systems were exposed, and system characteristics that give rise to vulnerabilities, to uncover some of the most insightful results.
This study investigated potential impacts of climate change on travel disruption resulting from road closures in two urban watersheds in the Portland, Oregon, metropolitan area. We used ensemble climate change scenarios, a hydrologic model, a stream channel survey, a hydraulic model, and a travel forecast model to develop an integrated impact assessment method. High-resolution climate change scenarios are based on the combinations of two emission scenarios and eight general circulation models. The Precipitation-Runoff Modeling System was calibrated and validated for the historical period of 1988 and 2006 and simulated for determining the probability of floods for 2020 through 2049. We surveyed stream cross-sections at five road crossings for stream channel geometry and determined flood water surface elevations using the Hydrologic Engineering Centers River Analysis System (HEC-RAS) model. Four of the surveyed bridges and roadways were lower in elevation than the current 100-year flood water surface elevation, leading to relatively frequent nuisance flooding. These roadway flooding events will become more frequent under some climate change scenarios in the future, but climate change impacts will depend on local geomorphic conditions. Whereas vehicle miles traveled was not significantly affected by road closure, vehicle hours delay demonstrated a greater impact from road closures, increasing by 10 percent in the Fanno Creek area. Our research demonstrated the usefulness of the integration of top-down and bottom-up approaches in climate change impact assessment and the need for spatially explicit modeling and participatory planning in flood management and transportation planning under increasing climate uncertainty.
A unified exposition of the principles of optimum use of renewable and nonrenewable natural resources, set in the framework of historical natural resource concerns and real world resource markets. Utilizes most up-to-date theoretical and empirical research results from economics, geology, hydrology, and the environmental sciences. Characterizes the role of natural resources in long-term economic growth; describes and analyzes problems and policy issues of energy, nonenergy minerals, forestry, fisheries, water resources, and preserved natural environments. Reviews factors critical to the future and seeks to derive a responsible natural resources policy'' that emphasizes intergenerational equity. Includes several extended case studies.
Ecosystems are capital assets: When properly managed, they yield a flow of vital goods and services. Relative to other forms
of capital, however, ecosystems are poorly understood, scarcely monitored, and--in many important cases--undergoing rapid
degradation. The process of economic valuation could greatly improve stewardship. This potential is now being realized with
innovative financial instruments and institutional arrangements.
Benefit-cost analysis can play an important role in legislative and regulatory policy debates on protecting and improving
health, safety, and the natural environment. Although formal benefit-cost analysis should not be viewed as either necessary
or sufficient for designing sensible public policy, it can provide an exceptionally useful framework for consistently organizing
disparate information, and in this way, it can greatly improve the process and, hence, the outcome of policy analysis. If
properly done, benefit-cost analysis can be of great help to agencies participating in the development of environmental, health,
and safety regulations, and it can likewise be useful in evaluating agency decision-making and in shaping statutes.
In the modernist era water is discussed as a single substance which has multiple uses. I argue that from a normative perspective water should be discussed in the plural term 'waters', as they constitute a variety of 'things' with a similar chemical composition. Waters are composed of multiple 'needs', which are uses with a normative rationale, and of 'wants', which are desires that should be seen as economic demands. Moreover waters should be also differentiated by source – natural, recycled or produced. This new language of water has direct policy implications. Needs, differentiated into direct human needs, spiritual needs, environmental needs and community needs, which may be prioritized, should be supplied regardless of cost considerations. 'Wants' and produced water should be priced at the full social cost of supply. Hence, while the rates at which needs are supplied should be determined by affordability, regardless of spatial differentiation in supply cost, the pricing of water supplied for 'wants' will vary over space. Thus water which is supplied through the same pipe to the same house may be subject to different pricing logics. However, there are many nuances to these generalizations, which have still to be fleshed out.
Our aim in this essay is to identify and analyze some of the difficulties with interdisciplinary integration of economic and ecological contributions to the study of biodiversity loss. We develop our analysis from a widely accepted definition of economics which is based on the concept of scarcity. Taking a closer look at this notion, we find that economics actually limits itself to a very particular aspect of scarcity, which we denote as relative scarcity. We describe in what respect the economic approach towards biodiversity is based on this notion, and also reflect on the specific understanding of the relation of humans and nature behind the economic approach. We then turn to absolute scarcity as another notion of scarcity, and show that this is not within the scope of economics, but has been a theme of ecology and ecological economics. We describe in which way ecological and ecological–economic approaches towards biodiversity are based on the idea of absolute scarcity, and also reflect on the specific understanding of the human–nature relationship behind this notion of scarcity. Against this background, we discuss the roles of economics and ecology for nature conservation. We conclude that the interdisciplinary integration of ecology and economics requires a philosophical underpinning, and suggest a framework for further research.
In an article in Water Resources Research, 1966 Joe B. Stevens tried to estimate direct recreational benefits from water pollution control by using market demand curves for a sport fishery. The quality of the fishery was represented by the angling success per unit of effort. Water pollution would cause a deterioration in the quality, i.e. would decrease angling success. By estimating a demand function for the sport fishery, both as a function of the price of using the fishery and as a function of the quality variable, Stevens thought he could calculate the recreational benefits or the willingness to pay for maintaining constant quality, from various areas under the demand curves. Stevens' idea, although a very sound one, was not developed in a rigorous way and his conclusions were therefore vague. The aim of this article is to develop a theory which can lend support to calculations such as those presented by Stevens. The ideas in this article are first presented intuitively in a non rigorous way. Then Section III includes a brief review of elements from demand analysis and a statement of the marginal conditions for Pareto optimality in an economy with public goods. A theoretical framework is developed in Section IV which enables derivation of the willingness to pay for public goods in certain cases on the basis of information on demand functions for private goods.
The article considers how the preservation of biodiversity is morally justified in some of the key texts on environmental ethics, i.e. whether or not biodiversity can be justified as a moral end in itself. The views are classified according to the criteria which they hold to be the ultimate moral beneficiaries; positions are named as anthropocentrism, biocentrism and ecocentrism. In general, they are not in favor of regarding biodiversity as intrinsically valuable, but think its moral value as derivative. This means that the myriad characters of life on Earth are to be maintained as diverse because of their instrumental value for the constituents. It seems that Naess's deep ecology is the only major position that argues for biodiversity's intrinsic value, but this view has proved to be problematic.
Protecting the worlds freshwater resources requires diagnosing threats over a broad range of scales, from global to local. Here we present the first worldwide synthesis to jointly consider human and biodiversity perspectives on water security using a spatial framework that quantifies multiple stressors and accounts for downstream impacts. We find that nearly 80% of the worlds population is exposed to high levels of threat to water security. Massive investment in water technology enables rich nations to offset high stressor levels without remedying their underlying causes, whereas less wealthy nations remain vulnerable. A similar lack of precautionary investment jeopardizes biodiversity, with habitats associated with 65% of continental discharge classified as moderately to highly threatened. The cumulative threat framework offers a tool for prioritizing policy and management responses to this crisis, and underscores the necessity of limiting threats at their source instead of through costly remediation of symptoms in order to assure global water security for both humans and freshwater biodiversity.
An appropriate, rapid and effective response to extreme precipitation and any potential flood disaster is essential. Providing an accurate estimate of future changes to such extreme events due to climate change are crucial for responsible decision making in flood risk management given the predictive uncertainties. The objective of this article is to provide a comparison of dynamically downscaled climate models simulations from multiple model including 12 different combinations of General Circulation Model (GCM)–regional climate model (RCM), which offers an abundance of additional data sets. The three major aspects of this study include the bias correction of RCM scenarios, the application of a newly developed performance metric and the extreme value analysis of future precipitation. The dynamically downscaled data sets reveal a positive overall bias that is removed through quantile mapping bias correction method. The added value index was calculated to evaluate the models' simulations. Results from this metric reveal that not all of the RCMs outperform their host GCMs in terms of correlation skill. Extreme value theory was applied to both historic, 1980–1998, and future, 2038–2069, daily data sets to provide estimates of changes to 2- and 25-year return level precipitation events. The generalized Pareto distribution was used for this purpose. The Willamette River basin was selected as the study region for analysis because of its topographical variability and tendency for significant precipitation. The extreme value analysis results showed significant differences between model runs for both historical and future periods with considerable spatial variability in precipitation extremes. Copyright © 2012 John Wiley & Sons, Ltd.
Increasing competition for water across sectors increases the importance of the river basin as the appropriate unit of analysis to address the challenges facing water resources management; and modeling at this scale can provide essential information for policymakers in their resource allocation decisions. This paper introduces an integrated economic-hydrologic modeling framework that accounts for the interactions between water allocation, farmer input choice, agricultural productivity, nonagricultural water demand, and resource degradation in order to estimate the social and economic gains from improvement in the allocation and efficiency of water use. The model is applied to the Maipo River Basin in Chile. Economic benefits to water use are evaluated for different demand management instruments, including markets in tradable water rights, based on production and benefit functions with respect to water for the agricultural and urban-industrial sectors.
Social, economic, and environmental systems in arid regions are vulnerable to disruptions in water supplies that are likely to accompany future climate changes. With a particular focus on the Rio Grande in New Mexico, this paper uses a hydro-economic model to integrate plausible changes in population and climate over the coming 70 yr. Specifically, projections of regional population growth are combined with alternative climate scenarios in order to simulate changes in streamflows, water supplies, and water demands within a framework that economizes water use. The study uses 3 climate change scenarios across 2 distinct future time periods to model runoff, water supply, and water demand changes, and estimate the economic and water-use consequences. Specifically, temperature and precipitation scenarios were generated using results from 3 general circulation models (GCMs), namely, HadCM3 (Hadley Centre for Climate Prediction and Research Met Office), CSIRO (Commonwealth Scientific and Industrial Research Organization of Australia), and the GFDL0 (Geophysical Fluid Dynamics Laboratory of the National Oceanic and Atmospheric Administration), all of which were driven by the A1B emissions scenario from the Intergovernmental Panel on Climate Change's Special Report on Emissions Scenarios. The WATBAL hydrologic model and the Rio Grande hydro-economic model were used to model the hydrologic and economic consequences, respectively. Findings indicate that agricultural water users could be most affected by curtailed deliveries and higher water scarcity. Municipal water users are likely to face higher delivery costs as competition for scarce surface water supplies rises; however, groundwater supplies provide an effective buffer for many of the municipal systems and help ameliorate price spikes.
Summer streamflow is a vital water resource for municipal and domestic water supplies, irrigation, salmonid habitat, recreation, and water-related ecosystem services in the Pacific Northwest (PNW) in the United States. This study detects significant negative trends in September absolute streamflow in a majority of 68 stream-gauging stations located on unregulated streams in the PNW from 1958 to 2008. The proportion of March streamflow to annual streamflow increases in most stations over 1,000 m elevation, with a baseflow index of less than 50, while absolute March streamflow does not increase in most stations. The declining trends of September absolute streamflow are strongly associated with seven-day low flow, January–March maximum temperature trends, and the size of the basin (19–7,260 km2), while the increasing trends of the fraction of March streamflow are associated with elevation, April 1 snow water equivalent, March precipitation, center timing of streamflow, and October–December minimum temperature trends. Compared with ordinary least squares (OLS) estimated regression models, spatial error regression and geographically weighted regression (GWR) models effectively remove spatial autocorrelation in residuals. The GWR model results show spatial gradients of local R 2 values with consistently higher local R 2 values in the northern Cascades. This finding illustrates that different hydrologic landscape factors, such as geology and seasonal distribution of precipitation, also influence streamflow trends in the PNW. In addition, our spatial analysis model results show that considering various geographic factors help clarify the dynamics of streamflow trends over a large geographical area, supporting a spatial analysis approach over aspatial OLS-estimated regression models for predicting streamflow trends. Results indicate that transitional rain–snow surface water-dominated basins are likely to have reduced summer streamflow under warming scenarios. Consequently, a better understanding of the relationships among summer streamflow, precipitation, snowmelt, elevation, and geology can help water managers predict the response of regional summer streamflow to global warming.
Patrones espaciales de las tendencias de los caudales de marzo y septiembre en el Pacífico Noroccidental.
Los caudales (streamflows) de verano son recursos hídricos vitales para el abastecimiento de agua municipal y domestico así como para el riego agrícola, el hábitat de los salmónidos, la recreación, y para varios servicios de los ecosistemas en el Pacífico Noroccidental (Pacific Nortwest-PNW) de los Estados Unidos. Este estudio identifica tendencias negativas considerables en los caudales absolutos de septiembre en la mayoría de las 68 estaciones de medición situadas en ríos y arroyos no regulares del PNW entre 1958 y 2008. La proporción del caudal de marzo con respecto al caudal anual aumenta en la mayoría de las estaciones situadas a más de 1000 metros de altitud, que tienen un índice de caudal base (base flow index-BFI) de menos de 50, pero se mantiene estable en el resto (la mayoría) de las estaciones. Las tendencias decrecientes de los caudales absolutos de septiembre están fuertemente asociadas con el caudal mínimo para siete días (seven-day low), con las tendencias de temperatura máxima entre enero y marzo, y con el tamaño de la cuenca (19-7,260 km2). Las tendencias crecientes de la proporción del caudal total correspondiente a marzo están asociadas con la elevación, con un equivalente a agua de la nieve de abril (one April snow wáter equivalent -SWE), con la precipitación de marzo, el center timing (TC) de los caudales, y con las tendencias de temperatura mínima entre octubre y diciembre. En comparación con los estimados de modelos de regresión de tipo mínimos cuadrados ordinarios (ordinary least squares-OLS), los modelos de regresión de error espacial (spatial error regression-SER) y de regresión ponderada geográficamente (geographically weighted regression-GWR) eliminan eficazmente la autocorrelación espacial en los residuos. Los resultados del modelo GWR producen mapas con gradientes espaciales donde los valores de los R2 locales son consistentemente más altos en las cascadas del norte. Este resultado pone de manifiesto que diferentes factores hidrológicos del paisaje, tales como la geología y la distribución estacional de la precipitación, también influyen en las tendencias de los caudales en el PNW. Adicionalmente, los resultados del modelo de análisis espacial muestran que la inclusión de diversos factores geográficos ayuda a aclarar la dinámica de las tendencias de los caudales en un área geográfica grande, corroborando la mayor utilidad de modelos con enfoque de espacial sobre modelos. Los resultados indican también que en cuencas transicionales (entre lluvia y nieve) donde predominan las aguas superficiales existe una probabilidad más alta de reducccion de caudal de verano en el contexto de escenarios de calentamiento. En consecuencia, una mejor comprensión de las relaciones entre caudal de verano, la precipitación, el derretimiento de nieve, la elevación y la geología puede ayudar a los gestores del agua a predecir la respuesta de los caudales de verano en un escenario de calentamiento global.
夏季径流是美国太平洋西北部地区(PNW)市政与居民水供应、灌溉、鱼类栖息、娱乐及水相关生态系统服务的重要来源。本研究通过1958–2008年PNW地区68个地理位置上未调节的径流测量站分析揭示出九月绝对径流量与该地区水来源呈显著的负相关趋势。三月径流占年际径流量的比例在大多数海拔超过1000米的地区是增加的，然而大多数地区基本径流指数（BFI）少于50，表明三月绝对径流量在多数地区并没有增加。九月绝对径流量的下滑趋势与年均为期7天的低流量，1月–3月最大温度趋势及流域面积（19–7,260 km2）呈强相关性，而三月绝对径流量微量增加的趋势则与海拔高度，四月一日的雪水当量（SWE），三月降水，径流中心时序（CT）和十月至十二月最小温度趋势相关。与OLS(普通最小二乘法估计)回归模型相比，空间滞后回归（SER）和地理加权回归模型（GWR）能有效剔除空间自相关的残差而更有效。GWR结果显示局部R2值在空间上渐变梯度，并且在北美洲喀斯喀特山脉（Cascade）：北部地区高于其他地区。该发现表明不同水文景观因子，如地质、降水的季节分布，也会对PNW的径流趋势产生影响。另外，我们的空间分析模型结果显示，考虑多种地理因素可解析大面积的地理区域中径流量空间分布趋势的动力机制， 为预测径流趋势提供一种优于OLS空间估计回归模型的空间分析方法。结果表明气候变暖背景下，季节性降水、地表水主导的流域极可能减少夏季径流量。因此，更好地理解夏季径流量与降水、融雪水、海拔和地质的关系，可帮助水资源管理者预测区域夏季径流对全球变暖的响应。
Doyle, Martin W., 2012. America’s Rivers and the American Experiment. Journal of the American Water Resources Association (JAWRA) 48(4): 820‐837. DOI: 10.1111/j.1752‐1688.2012.00652.x
Abstract: America’s rivers are managed, over long periods of time, based on the most basic ideologies of the United States (U.S.) government. An essential notion of the U.S. government, and thus a necessity of river management, is governing as experiment. This leads to three necessary characteristics of river management: (1) adapting management practices based on experience and thus creating management and agency structures that are highly malleable and that can change directions, (2) overlapping of management roles and responsibilities between agencies which includes intentional redundancy and interagency competition, and (3) federalism — the devolution of responsibilities between national, state, and other unit governments (e.g., municipalities, counties). While these characteristics are often criticized as inefficient, in fact they have provided a surprisingly effective system for river management that has responded to the needs of society at different times and in different places. A key question for river and water resource managers is whether this particular system, so initially unappealing, is best able to meet the future needs of the U.S.
In an article in Water Resources Research 1966 [3], Joe B. Stevens tried to estimate direct recreational benefits from water pollution control by using market demand curves for a sport fishery. The quality of the fishery was represented by the angling success per unit of effort. Water pollution would cause a deterioration in the quality, i.e. would decrease angling success. By estimating a demand function for the sport fishery, both as a function of the price of using the fishery and as a function of the quality variable, Stevens thought he could calculate the recreational benefits or the willingness to pay for maintaining constant quality, from various areas under the demand curves.
The joint behavior of drought characteristics under climate change is evaluated using the copula method, which has recently attained popularity in the analysis of complex hydrologic systems with correlated variables. Trivariate copulas are applied, in this study, to analyze the major drought variables, including duration, severity, and intensity, in Oregon's Upper Klamath River Basin. Among the variables, results show that duration severity exhibits the strongest correlation, whereas duration intensity exhibits the least correlation. The impact of climate change on future droughts is evaluated using five general circulation models (GCMs) under one emission scenario. Despite more intense extreme events that are expected to occur in most parts of the globe in the future, the results of this study show that the Upper Klamath River Basin in the Pacific Northwest will experience less intense droughts affected by climate change. Compared with historical events, an overall decrease in drought duration and severity is estimated for this study area in the time period of 2020–2090 with maximum drought duration shown to decline from 8 to 5 months. Among the five GCMs employed in this study, GFDL-CM2.1 and CSIRO-MK3.0 are identified as the wettest and driest projections, respectively. High uncertainty associated with GCM products is demonstrated in the analysis of return period by means of bivariate copulas. However, all projections result in larger return periods (i.e., less frequent droughts) compared with historical droughts during the reference period. DOI: 10.1061/(ASCE)HE.1943-5584 .0000532. © 2013 American Society of Civil Engineers.
Cost-benefit analysis is reducible to several major principles that collectively describe the assumption base, objectives, analytical tasks, and merits of this important project assessment methodology. Here, these principles are identified and described using basic economic terms and concepts. The deficiencies of cost-benefit analysis also emerge from these principles, and these issues are also observed in this article. Further discussion investigates high-profile issues in the economic assessment of environmental affects and the economic effects on sectors linked to water-project-impacted sectors.
We use regional climate model (RCM) simulations from the North American Regional Climate Change Assessment Program (NARCCAP) to evaluate implications of climate change for the discharge of the Colorado River in the mid-21st century. We compare historical RCM simulations and simulations from their host global general circulation models (GCMs) to one-eighth degree gridded observations of precipitation, surface air temperature, and runoff (generated by the Variable Infiltration Capacity (VIC) land surface model forced with gridded observations) for the historical period 1970-1999. The RCMs capture the primary features of observations better than their host GCMs in part because of their ability to better represent strong upward lift in topographically complex regions. Although the RCMs do not significantly improve the simulation of precipitation, their ability to better represent surface temperature in mountainous regions has important effects on simulations of evapotranspiration, snowpack, and runoff. In the Colorado River basin, projected mid-21st century runoff changes are mostly impacted by the combination of snow cover change in winter, temperature change in spring, and precipitation change in summer. In particular, the response of cold season temperatures in headwater streams is key to determining the basin's susceptibility to a warming climate. Because of the cooler temperature and higher snowline in RCMs relative to GCMs, the RCMs project less warming in the spring and thus generate smaller decreases in runoff, both during spring and annually, as compared with GCMs. Changes in surface air temperature, runoff, and snow water equivalent at high elevations all indicate that headwater streams of the Colorado River are less susceptible to a warming climate in climate change simulations that use RCMs than in simulations that use GCMs. Nonetheless, the 50 km NARCCAP grid resolution has some limitations in resolving orographic effects, which suggests that there may remain residual biases in the climatic sensitivity of the RCM simulations.
A variety of methods have been used to measure post-fire erosion across the western United States. We grouped these measurements into four methods: (1) point measurements on hillslopes, (2) hillslope plot measurements, (3) suspended-sediment and bed load sampling in channels, and (4) channel volume measurements of erosion or deposition. We classified features identified as "incised tributaries" or "gullies" as channel erosion. Only measurements made within two years of a fire were included in the synthesis. The measurement methods were stratified into seven different rainfall regimes based on seasonal rainfall type and rainfall intensities within each seasonal type. Post-wildfire sediment yields varied over five orders of magnitude for the different rainfall regimes. While differences in sediment yields exist across different rainfall regimes, a major source of variance is a result of the different methods used to measure post-fire erosion. A median sediment yield value for each measurement method was calculated. The average median sediment yield based on the channel volume method of 190 T/ha was greater than the sediment yields based on point measurements on hillslopes (29 T/ha), on hillslope plot measurements (14 T/ha), and on channel suspended-sediment and bed load sampling (2.5 T/ha) methods. This suggests that the channels are more important than the hillslope as sources of available sediment after wildfire. The lack of correlation of sediment yields with topographic slope and soil erodibility suggests that sediment availability may be more important than slope or erodibility in determining the sediment yield after wildfire
In arid countries worldwide, social conflicts between irrigation-based human development and the conservation of aquatic ecosystems are widespread and attract many public debates. This research focuses on the analysis of water and agricultural policies aimed at conserving groundwater resources and maintaining rural livelihoods in a basin in Spain's central arid region. Intensive groundwater mining for irrigation has caused overexploitation of the basin's large aquifer, the degradation of reputed wetlands and has given rise to notable social conflicts over the years. With the aim of tackling the multifaceted socio-ecological interactions of complex water systems, the methodology used in this study consists in a novel integration into a common platform of an economic optimization model and a hydrology model WEAP (Water Evaluation And Planning system). This robust tool is used to analyze the spatial and temporal effects of different water and agricultural policies under different climate scenarios. It permits the prediction of different climate and policy outcomes across farm types (water stress impacts and adaptation), at basin's level (aquifer recovery), and along the policies’ implementation horizon (short and long run). Results show that the region's current quota-based water policies may contribute to reduce water consumption in the farms but will not be able to recover the aquifer and will inflict income losses to the rural communities. This situation would worsen in case of drought. Economies of scale and technology are evidenced as larger farms with cropping diversification and those equipped with modern irrigation will better adapt to water stress conditions. However, the long-term sustainability of the aquifer and the maintenance of rural livelihoods will be attained only if additional policy measures are put in place such as the control of illegal abstractions and the establishing of a water bank. Within the policy domain, the research contributes to the new sustainable development strategy of the EU by concluding that, in water-scarce regions, effective integration of water and agricultural policies is essential for achieving the water protection objectives of the EU policies. Therefore, the design and enforcement of well-balanced region-specific polices is a major task faced by policy makers for achieving successful water management that will ensure nature protection and human development at tolerable social costs. From a methodological perspective, this research initiative contributes to better address hydrological questions as well as economic and social issues in complex water and human systems. Its integrated vision provides a valuable illustration to inform water policy and management decisions within contexts of water-related conflicts worldwide.
Research highlights
► Studies the Tualatin River in the Pacific Northwest, US to predict the impact of climate change on ecohydrologic parameters. ► Results show increased future storm flows based on current emissions trends. ► Significant impacts to hydrologic ecotones and LiDAR-derived vegetative features is anticipated.
While it is sometimes suggested that ‘water’ was regarded as an element prior to the discovery of its compound nature in the 18th century, most premodern understandings of water emphasized the diverse characteristics of many waters. Such views were developed and sustained within several distinct contexts: Aristotelian natural philosophy, classical natural history, folklore and religion, and the promotion of mineral waters. During the 19th century this empiricist view of waters as many was replaced by an essentialist view in which water was a commodity with varying amounts and kinds of undesirable impurities. The continuing importance of these distinct conceptions of water is evident in the competition for public attention and consumer confidence between the bottled water industry, which is predicated on the concept of many unique waters, and the public water industries, which present water as a monolithic commodity. It will be important for water policy makers to be sensitive to a wide range of conceptions of water that retain appeal. Such conceptions may have significant impact on public assessment of water technologies.
The interdisciplinary nature of water resources problems requires the integration of technical, economic, environmental, social, and legal aspects into a coherent analytical framework. This paper presents the development of a new integrated hydrologic-agronomic-economic model in the context of a river basin in which irrigation is the dominant water use and irrigation-induced salinity presents a major environmental problem. The model's main advantage is its ability to reflect the interrelationships between essential hydrologic, agronomic, and economic components and to explore both economic and environmental consequences of various policy choices. All model components are incorporated into a single consistent model, which is solved in its entirety by a simple but effective decomposition approach. The model is applied to a case study of water management in the Syr Darya River basin in Central Asia.
This chapter reviews the application of economic concepts to study the consumption, supply, and allocation of water resources. Water management poses a wide array of issues for economists because few commodities are so pervasively involved in human economic activities. To an important degree, the location and intensity of economic activities depend on the availability of water for drinking, for agricultural and industrial production, for sanitation and waste assimilation, for transportation, and for aesthetic and recreational benefits. Water is said to be the only substance that exists in all three physical states—solid, liquid, and gas—within the normal temperature range found on the earth's surface. Through the process known as the hydrologic cycle, the earth's water inventory is continually being transformed among the three states. No form of life on the earth can exist without water. Water is a universal solvent. The chapter reviews those characteristics of water resource systems that serve to set them apart from other resources, with particular reference to the attributes that serve as the basis for public intervention. It also describes the nature of interventions that have been made and emphasizes the need for evaluating them in terms of their objectives.
In an earlier global climate-change study, air temperature and precipitation data for the entire twenty-first century simulated from five general circulation models were used as input to precalibrated watershed models for 14 selected basins across the United States. Simulated daily streamflow and energy output from the watershed models were used to compute a range of statistics. With a side-by-side comparison of the statistical analyses for the 14 basins, regional climatic and hydrologic trends over the twenty-first century could be qualitatively identified. Low-flow statistics (95% exceedance, 7-day mean annual minimum, and summer mean monthly streamflow) decreased for almost all basins. Annual maximum daily streamflow also decreased in all the basins, except for all four basins in California and the Pacific Northwest. An analysis of the supply of available energy and water for the basins indicated that ratios of evaporation to precipitation and potential evapotranspiration to precipitation for most of the basins will increase. Probability density functions (PDFs) were developed to assess the uncertainty and multimodality in the impact of climate change on mean annual streamflow variability. Kolmogorov-Smirnov tests showed significant differences between the beginning and ending twenty-firstcentury PDFs for most of the basins, with the exception of four basins that are located in the western United States. Almost none of the basin PDFs were normally distributed, and two basins in the upper Midwest had PDFs that were extremely dispersed and skewed.