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Report on the Desert Encroachment Reconnaissance in Northern Sudan
... The term desertification refers to land degradation in the Earth's drylands, but has been interpreted in many different ways. In the 1970s, when the early satellite images became available to science and the general public, desertification was often related to the southward extension of the Sahara desert [1,2]. This perception appeared to be wrong, and since then a lot of debate has arisen about the definition of desertification, its causes, the severity, the global occurrence of desertification, and the impacts it has on the dryland populations. ...
... The earliest attempts to quantify desertification assessed the rate of Sahara desert encroachment [1,20]. Others criticized these assessments and found no evidence for large scale movement of the desert boundary but stated that the boundary between the Sahara desert and the more moist Sahelian zone is dynamic. ...
Desertification is defined as land degradation occurring in the global drylands. It is one of the global problems targeted under the Sustainable Development Goals (SDG 15). The aim of this article is to review the history of desertification and to evaluate the scientific evidence for desertification spread and severity. First quantitative estimates of the global extent and severity of desertification were dramatic and resulted in the establishment of the UN Convention to Combat Desertification (UNCCD) in 1994. UNCCD's task is to mitigate the negative impacts of desertification in drylands. Since the late 1990s, science has become increasingly critical towards the role of desertification in sustainable land use and food production. Many of the dramatic global assessments of desertification in the 1970s and 1980s were heavily criticized by scientists working in drylands. The used methodologies and the lack of ground-based evidence gave rise to critical reflections on desertification. Some even called desertification a myth. Later desertification assessments relied on remote sensing imagery and mapped vegetation changes in drylands. No examples of large areas completely degraded were found in the scientific literature. In science, desertification is now perceived as a local feature that certainly exists but is not as devastating as was earlier believed. However, the policy arena continues to stress the severity of the problem. Claims that millions of hectares of once productive land are annually lost due to desertification are regularly made. This highlights the disconnection between science and policy, and there is an urgent need for better dialogue in order to achieve SDG 15.
... Numerous examples (a) Figs. 7.9a, 7.9b, and 7.9c Early survey of the extent of desertification (Lamprey, 1988) (Fig.7.9a) contrasted with recent examples or remote sensing studies of vegetation greenness as a proxy for bioproductivity in the Sahel (Fig. 7.9b, Fig. 7.9c) ( Eklundh and Olsson, 2003;Herrman et al. 2005). ...
... (a) Figs. 7.9a, 7.9b, and 7.9c Early survey of the extent of desertification (Lamprey, 1988) (Fig.7.9a) contrasted with recent examples or remote sensing studies of vegetation greenness as a proxy for bioproductivity in the Sahel (Fig. 7.9b, Fig. 7.9c) (Eklundh and Olsson, 2003;Herrman et al. 2005). ...
... Numerous examples (a) Figs. 7.9a, 7.9b, and 7.9c Early survey of the extent of desertification (Lamprey, 1988) (Fig.7.9a) contrasted with recent examples or remote sensing studies of vegetation greenness as a proxy for bioproductivity in the Sahel (Fig. 7.9b, Fig. 7.9c) (Eklundh and Olsson, 2003;Herrman et al. 2005). ...
... Thomas Malthus' prediction that unchecked population growth would eventually surpass agricultural production, leading to dwindling food supply per person. (Malthus, 1798) (Lamprey, 1988) (Fig.7.9a) contrasted with recent examples or remote sensing studies of vegetation greenness as a proxy for bioproductivity in the Sahel (Fig. 7.9b, Fig. 7.9c) (Eklundh and Olsson, 2003;Herrman et al. 2005). ...
Putting the drylands to productive use has proved to be a persistent challenge. Low rainfall amounts ensure that, generally, returns will be modest from most agricultural uses. Extreme interannual variability of rainfall presents a diabolical trap, which means that ventures aimed at maximizing agricultural returns tend to be short-lived and can lead to a degradation of the land resource.
... Many researchers assessed the desertification process in Northern Kordofan-Province; there remain a great deal of disagreement about the controlling factors of desertification. For example, some researchers have attributed the desertification in Northern Kordofan-province to continuous decrease in productivity of the food crops, which leads to infrequent famines and food shortage (Hielkema et al., 1986), while others attributed Northern Kordofan desertification to human activities such as changes in fire regimens, excessive woodcutting, and over-grazing rather than climate change (Kheiry, 2007;Lampery, 1975). However, some researchers found that cli-mate factors such as droughts, temperature and rainfall changes were the main causes for desertification (Ahlcorona, 1988). ...
... Human activities were the principal influence, which resulted in 67.32% of desertification expansion. Agreement with (Kheiry, 2007;Lampery, 1975) results, which indicated that human activities such as changes in fire regimens, excessive woodcutting, and over-grazing were the dominant cause of desertification expansion in the Northern Kordofan regions. About 97.7% of desertification reversion induced by climate change, and 2.3% was induced by human activities. ...
Using net primary productivity (NPP) as an indicator to desertification driving factor and expansions is one of the importance tools in the assessment of the contribution of climate change and human activity in desertification. In this study we used three types of net primary productivity; the actual NPP, Potential NPP and HNPP (human appropriation of NPP) to discriminate the relative role of climate change and human activities in desertification from 2000 to 2008 in Northern Kordofan province-Sudan. The results showed, 63.75% of the study area experienced desertification expansion. Within which, 67.32% was induced by Human activities compared with 32.03% caused by climate change and 0.65% caused by a combination of the two factors. By contrast, climate change is the dominant factor of desertification reversion, 2.3% of desertification reversion caused by human activities compared with 97.7% induced by climate change and there isn’t interaction between climate change and human activities in reversion area. The largest area of expansion and reversion occurred in northeast and western parts of the study area respectively. We developed two propositions in the study area. First, the desertification expansion was induced by human activities, whereas desertification reversion was induced by climate change as typified in north south part, central part and western part. Second, both desertification expansion and reversion was induced by climate change as typified in northeast part of study area.
... Different interpretations of the desert boundary, owing in part to differences in rainfall conditions in the years of assessment, led to the misnomer that the desert was advancing. Figure adapted from Lamprey (1988). (Oldeman et al. 1991). ...
... Remote sensing products, such as air photos and early Landsat images, were used in early mapping of the formation of desert patches around villages (Ibrahim 1978) and the southward expansion of the Sahara desert (Lamprey 1988) (Fig. 5.1). However, this early use of remote sensing was limited to local scales and did not take into account the seasonality and interannual variability of rainfall and vegetation cover. ...
Satellite remote sensing, in particular the analysis of coarse resolution time series of vegetation indices, has played an important role in challenging earlier assumptions of widespread desertification in the Sahel. Findings of such analyses show a greening trend in much of the region since the early 1980s, which seems to suggest a positive development. On the other hand, a growing number of field studies of vegetation dynamics across the Sahel offer a more fine-scaled and nuanced picture of changes. Of particular interest with respect to degradation and rehabilitation is the woody component of the vegetation cover, which is less affected by short-term fluctuations in precipitation than the herbaceous component. We synthesized findings from published field studies on changes in the abundance and diversity of woody vegetation across the Sahel and spatially compared them with the remotely sensed greenness trends. Many field sites reported a decline in the abundance of woody vegetation since before the great droughts, in particular of large trees. In addition, the woody vegetation shifted from a diverse species composition towards fewer and more drought tolerant species in the majority of sites. However, some success stories of agroforestry management stood out as well, where formerly degraded farmlands were rehabilitated and in some cases have reached even higher tree densities than in the 1960s. The discrepancy between satellite-observed greening trends and changes in woody vegetation on the ground—in both directions—emphasizes the need of integrating multiple perspectives and scales in the interpretation of greening trends with respect to desertification.
... Concerning the characterization of these changes, on the one hand, the increase in NDVI for the whole region according to NOAA is contrary to the claims of irreversible '"desertification" generalized in the Sahel [80]. [8,10,81,82]. Recent results based on NDVI-MODIS (2000-2019) and NOAA time series across the Mann-Kendall show an increase in vegetation indices over large areas in Casamance since the mid-1990s. ...
Contrary to claims of widespread irreversible degradation of vegetation and landscapes in West Africa, a recent increase in seasonal vegetation indices of Sahelian areas has been observed, which has been interpreted as a consequence of the rainfall recovery after the major droughts (1968–1994). This paper aims at revealing the climatic drivers of such greening in Casamance. A multi-scalar and multi-satellite remote sensing approach was implemented to study the temporal trends of vegetation activity and their relationships with rainfall in Lower and middle Casamance. The datasets used are the NOAA NDVI (GIMMS) from 1982 to 2015, the MODIS NDVI (MOD13Q1) from 2000 to 2019, and rainfall data from the Ziguinchor station from 1982 to 2017. These two NDVI time series were studied, on the one hand, with a classification method to discretize the different vegetations according to the rhythms and intensities of their vegetation activity throughout the year and, on the other hand, with Mann–Kendall’s correlation to reveal the trends. Almost three-quarters (72.5%) of the pixels show a significant positive trend (regreening) between 1982 and 2015. The simple correlation between NDVI and rainfall is very low (r² = 0.17) but both lagged correlation (r² = 0.86) and the correlation between NDVI and cumulated rainfall of longer periods (r² = 0.75) are strong. In other terms, after 1998 stronger rainfall in July and August give stronger NDVI in October and November. While a rainfall positive trend since the 1980s appears to be the main causal factor for the increase in vegetation indices, negative trends were also locally observed that are not explained by the rainfall-vegetation relationship and thus hypothetically a human-induced change.
... Over this period, studies documented a tendency toward dryness and desertification across the region, leading to decreases in mean annual discharge (e.g. Dregne 1986, Lamprey 1988, Hulme et al. 2001, Paturel et al. 2003. Furthermore, Tirogo et al. (2016) analyzed rainfall and discharge records in Burkina Faso, finding a significant break in the rainfall time series around 1970 that corresponded with deficits in baseflow. ...
Baseflow is an important water resource because it supplies streamflow between precipitation events and during dry seasons. We report the first continental assessment of baseflow in Africa by analyzing the baseflow index (BFI), baseflow seasonality, and monthly baseflow trends for three periods (1950-2018, 1950-1980, and 1981-2018). To explain changes in baseflow, we analyze precipitation trends. Results highlight that the baseflow season in west-central Africa occurs during August-November. In southern and northern Africa, the baseflow season is similar (January-May and January-April, respectively). Trend analysis detected monthly baseflow decreases in west-central Africa over the entire record and from 1950-1980, with increases after 1980. A clear pattern was absent in southern Africa for the whole record, but increases were detected earlier and decreases from 1981-2018. In northern Africa, decreasing baseflow trends were pronounced over the whole record, with no clear shift present. Precipitation trends were only consistent with baseflow changes in west-central Africa.
... Confusion over this issue has previously led to incorrect estimates of the rate of desertification and, in turn, to scepticism about whether desertification actually exists [71]. For example, in 1977 UNEP reported that comparing aerial survey observations with an 18-year-old map of the Sahara Desert's southern border implied that the desert was moving south at over 5 km per annum [106]. Scientific scepticism about the existence of desertification grew in the late 1980s [71], after analysis of low spatial resolution satellite images showed that while the boundary between the Sahara Desert and the Sahelian region shifted south in 1981, it moved north in 1985 when rainfall returned [60,107,108]. ...
Continuing uncertainty about the present magnitudes of global environmental change phenomena limits scientific understanding of human impacts on Planet Earth, and the quality of scientific advice to policy makers on how to tackle these phenomena. Yet why global environmental uncertainties are so great, why they persist, how their magnitudes differ from one phenomenon to another, and whether they can be reduced is poorly understood. To address these questions, a new tool, the Uncertainty Assessment Framework (UAF), is proposed that builds on previous research by dividing sources of environmental uncertainty into categories linked to features inherent in phenomena, and insufficient capacity to conceptualize and measure phenomena. Applying the UAF shows that, based on its scale, complexity, areal variability and turnover time, desertification is one of the most inherently uncertain global environmental change phenomena. Present uncertainty about desertification is also very high and persistent: the Uncertainty Score of a time series of five estimates of the global extent of desertification shows limited change and has a mean of 6.8, on a scale from 0 to 8, based on the presence of four conceptualization uncertainties (terminological difficulties, underspecification, understructuralization and using proxies) and four measurement uncertainties (random errors, systemic errors, scalar deficiencies and using subjective judgment). This suggests that realization of the Land Degradation Neutrality (LDN) Target 15.3 of the UN Sustainable Development Goal (SDG) 15 (“Life on Land”) will be difficult to monitor in dry areas. None of the estimates in the time series has an Uncertainty Score of 2 when, according to the UAF, evaluation by statistical methods alone would be appropriate. This supports claims that statistical methods have limitations for evaluating very uncertain phenomena. Global environmental uncertainties could be reduced by devising better rules for constructing global environmental information which integrate conceptualization and measurement. A set of seven rules derived from the UAF is applied here to show how to measure desertification, demonstrating that uncertainty about it is not inevitable. Recent review articles have advocated using ‘big data’ to fill national data gaps in monitoring LDN and other SDG 15 targets, but an evaluation of a sample of three exemplar studies using the UAF still gives a mean Uncertainty Score of 4.7, so this approach will not be straightforward.
... This understanding finally gained more support from policymakers and the initial idea of spreading deserts was dismissed once and for all (Grainger et al., 2000). 7 As such, it can be seen from the 1977 UNCOD Plan of Action to Combat Desertification (PACD) that the major outcome of the 5 Ollson (1993) provided details why the first evidence about the advancing of the Sahara in 1957-1975 observed by WWF expert Hugh Lamprey (Lamprey 1975) was totally wrong. 6 Drylands include arid, semi-arid, and dry sub-humid areas, and exclude hyper-arid areas or true deserts (Hulme et al., 1992). ...
This review focuses on the role of science-policy interactions in the transformation of the United Nations Convention to Combat Desertification (UNCCD) from being narrow (region specific) environmental agreement to a position of global stewardship of land resources. Desertification as an environmental issue first appeared on the international agenda in the late 1970s as a reaction to the devastating Sahel droughts in 1969–1973. There was general agreement in both scientific and political circles regarding the existence of a negative global trend in drylands caused mostly by human factors. In the 1990s pioneer studies, based on remote sensing, had discovered that the Sahel was “re-greening” due to some increase in precipitation while the effects of human activity were small in scale and not always negative. The new global satellite-based assessment–GLADA–showed that most degraded lands were located in humid climates but not in drylands. These findings have been generally accepted by the UNCCD leadership, and the term “land degradation” has gained prominence over “desertification” as the former is not associated with specific geographical conditions. The thematic area of the UNCCD is also gradually expanding due to the assimilation of new concepts such as “ecosystem services,” MDGs and SDGs. By successfully promoting adoption SDGs 15.3 on “Land Degradation Neutrality,” the UNCCD strengthens its position among the other Rio Conventions–UNFCCC and UNCBD.
... Desertification aggravates poverty and further expose inhabitants of arid communities to discomfort by limiting their adaptability to harsh environmental conditions. The Sahara Desert is encroaching southwards at a reported rate of 5-6 km per year [6,7], and 24-48 km per year [8,9]. Previous research attributes this primarily Most desert estimates are still on a global scale [19]. ...
In Nigeria, desertification has become one of the most pronounced ecological disasters, with the impacts mostly affecting eleven frontline States. This has been attributed to a range of both nat-ural and man-made factors. This study applied a remote sensing-based change detection and indicator analysis to explore land use/land cover changes and detect major conversions from ecologically active land covers to sand dunes. Results indicate that areas covered by sand dunes (a major indicator of desertification) have doubled over the 25 years under consideration (1990 to 2015). Although about 0.71 km2 of dunes have been converted to vegetation, indicative of the success of various international, national, local, and individual afforestation efforts, conversely about 10.1 km2 of vegetation were converted to sand dunes, implying around 14 times more de-forestation compared to afforestation. Juxtaposing the progression of sand dune with climate records of the study area and examining the relationship between indicators of climate change and desertification suggested a mismatch between both processes as increasing rainfall and lower temperatures observed in 1994, 2005, 2012, and 2014 did not translated into positive feedbacks for desertification in the study area. On average, our results reveal that sand dune is progressing at a mean annual rate of about 15.2 km2 in the study area. Based on this study’s land cover change, trend and conversion assessment, visual reconciliation of climate records with land cover data, statistical analysis, observations from ground-truthing, as well as previous literature, it can be inferred that desertification in Nigeria is less a function of climate change, but more a product of human activities driven by poverty, population growth and failed government policies. Further projections by this study also reveal a high probability of more farmlands being converted to sand dunes by the year 2030 and 2045 if current practices prevail.
... Nonetheless, there have been improvements in the approaches of land degradation assessment over the decades. Early workers like Lamprey [34] assessed desertification in Sahel as the rate of advance of Sahara by studying the vegetation cover maps and aerial images, while expert opinions emerged as a means of assessing dryland degradation; subsequently, a methodology based on soil and vegetation data was evolved [21,43]. Criticisms to this approach abound with major drawbacks being qualitative and subjective nature of the assessment [21,50]. ...
Land degradation, a major environmental problem, poses threats to agricultural, social and economic stability of many regions of the world. In India, ~ 37% of the total land area is estimated to be degraded. Although assessment of land degradation in arid and semiarid regions of India has advanced through remote sensing time-series analysis such as rain-use efficiency (RUE) and residual trend analysis (RESTREND), the sub-humid and other regions mostly remain unexplored in this respect. In this study, land degradation in Bihar, a sub-humid state, was quantitatively assessed through RUE and RESTREND from 1995 to 2011. RUE is the ratio of aboveground net primary productivity to precipitation and has been widely used as a measure of land degradation. RESTREND, on the other hand, examines the trend of NDVI residuals, which is the difference between observed NDVI and predicted NDVI from rainfall data. Results indicate that RESTREND effectively estimated the extent of human-induced land degradation in Bihar as 4.73 M ha. Agro-climatic zone IIIB, the driest zone, has the highest percentage of degraded lands (33%), while Zone IIIA has the lowest percent of degraded lands (17%). Zones I and II each account for 25% of the degraded lands, most of which are affected by waterlogging and salinity. Although other land degradation databases have also indicated a rapid increase in land degradation across Bihar, it needs more ground-based data collection to substantiate it. The problem, however, may further aggravate with global warming, which calls for policy interventions such as adopting agroforestry, practicing sustainable agriculture and making shifts in cropping patterns.
... Early experts on the subject promoted the idea of the 'encroaching desert', 'moving desert' or 'advancing desert' to illustrate desertification (Adu, 1982;Mainguet, 1994) with the latter citing several earlier studies related to this aspect of desertification. This 'expansion of the desert' theory culminated in the assertion by Lamprey (1975) that the Sahara as one example for arid zones was marching at a rate of 5.5 km per year. Central Asia as another example for arid zones is famous amongst other Asian countries with its huge deserts, namely Kizilkum, Karakum and Aralkum. ...
Uzbekistan has an arid climate and 85% of its territory consists of desert. This makes Uzbekistan vulnerable to desertification (desert extension). The consequent high evaporation rate of saline irrigation water and mineralized groundwater increases soil salinization. Salinization damages crops and this has hampered the country’s economy. Approximately 1 billion US dollars are lost each year. In addition, the responsible institutions still use a time-consuming, costly, and non-spatially specific in-situ soil salinity assessment method as their primary method. Therefore, I did two experiments that consider all of the above-mentioned aspects. The first experiment assesses the desert extension by monitoring sand dynamics in the Mirzachul Steppe by using GIS and remote sensing tools, and by applying scenarios that tackle the desert extension. The second experiment assesses soil salinity and compares in-situ and GIS-based methods by applying multi-criteria decision analysis to identify the current perception of the responsible institutions. To assess the desert extension, satellite images were downloaded to create a preliminary map of soil mechanic content. This analysis was conducted for the period 1994 to 2018 and the average annual rate of a desert extension was determined. This rate accounted for 143.2 hectares of desertification per year. I then formulated different scenarios to quantitatively project future states and expected changes till 2050. In total, four scenarios were created in which agroforestry was the main mitigation measure. The gap between these scenarios was a loss of 5,000 hectares of arable land. Narrative storylines were based on these scenarios to visualize the influence of mitigation measures on climate change and soil reactions. The scenario analysis showed that agroforestry can stop the desert extension by reducing future wind speed. The soil salinity maps from the GIS-based assessment method were compared with the in-situ data maps. August was selected to map soil salinity since this indicates the maximum of the growing season for cotton, which is the area’s main crop type. The maps proved visually very consistent and this impression was then statistically tested. The NDVI-GIS approach correlated almost 96% with the in-situ soil-quality-index values (R2 is 0.84). This enabled me to apply multi-criteria decision analysis to ascertain the most preferred soil salinity assessment method by scoring and ranking selected criteria. This analysis showed that the GIS-based approach outweighed the in-situ one. This initiated a discussion among representatives of the governmental institutions that use the in-situ soil salinity method as a primary method. They endorsed the GIS-based approach, but they stated that the GIS-based method cannot determine the chemical soil salinity types, which serve to help organize salt-leaching measures. I assumed that GIS indeed potentially can assess the degree of soil salinity, but the first step to formulating such an approach is to assess the chemistry type of soil salinity.
... Wind erosion is a predominant and a major process of desertification in Sudan, particularly in the northern part of the country due to the predominance aridity. Lamprey (1975) reported that the Sahara desert advanced at a rate of 5 to 6 km/year during the period 1958 -1975, some researcher doesn't agree with Lamprey. It is obvious according to his estimate the whole areas of Sudan must be covered by sand dunes or sand sheet. ...
Desertification is a result of complex interactions within coupled social relative contributions of climatic, anthropogenic and other drivers of desertification vary depending on specific socio awareness, show the current status, future challenges and emp through national strategies starting with determination the top priorities of research. Desertification induced by adverse human activities on agricultural lands creates a real research gap on vegetation degradation, trampling, trends of range land as well as continuous updating of carrying capacity of range lands, depletion of nutrients and organic matter due to excessive land use, ac pesticides that may be toxic to human, plants and animals. Due to limited financial resources for anti desertification research, there is a gap in combating desertification research generally, and wind erosion particularly suc flocculating materials that increase the non producing a rough and cloddy surface; maintaining sufficient vegetative cover; barriers or shelter belts barriers to reduce effective field length traveled by the wind. Furthermore there is a lack in studies need to conduct research on design number of rows, density and distance. The inevitable failure for desertification research that is not integrated with poverty alleviation programs, so there is a critical need to designing idea and sustainable management of natural resources to keep this human mass well and satisfied
... Images of mass starvation were beamed into Western living rooms and stimulated international concern (Thomas and Middleton 1994). In the drought aftermath, an assessment of environmental conditions in northern Sudan reported that the Sahara had encroached 100 kilometers south into semidesert scrub in the two decades since its boundary was originally mapped (Lamprey 1988, cited in Dodd 1994. ...
The ecological history of rangelands is often presented as a tale of devastation, where fragile drylands are irreversibly degraded through inappropriate land use. However, there is confusion about how to recognize and measure degradation, especially in low-productivity environments characterized by extreme natural variability and where abrupt and comprehensive management upheavals preclude benchmarks. These issues have important consequences for rangeland management programs, which are typically founded on presumptions of substantial and ongoing degradation from former “natural” states. We explore complementary approaches to critically assess degradation: the historical record, long-term grazing exclosures, surveys for potentially rare and sensitive plant species, and assessment of water-remote areas in relation to rare plant occurrence. Employing these approaches in inland Australia, we show that prevailing paradigms have become entrenched despite being inconsistent with empirical evidence. Our methodology can be applied to drylands with abrupt changes in management and contentious ecological narratives.
... Wind erosion is a predominant and a major process of desertification in Sudan, particularly in the northern part of the country due to the predominance aridity. Lamprey (1975) reported that the Sahara desert advanced at a rate of 5 to 6 km/year during the period 1958 -1975, some researcher doesn't agree with Lamprey. It is obvious according to his estimate the whole areas of Sudan must be covered by sand dunes or sand sheet. ...
Breast carcinoma is the commonest malignancy in women and it has become a major
health problem affecting women, worldwide. Mutations in the two breast cancer
susceptibility genes, BRCA1/BRCA2 increase the risk of developing breast
cancer.Objectives: To study the frequency of the three founder mutations; 185delAG and
the 5382insC in BRCA1and the 6174delTin BRCA2 genes, using the Multiplex PCR
Technique. Methods:In this study 150 patients with familial breast cancer diagnosed
pathologically as having breast cancer collected from middle and south of Iraq from May
2017 to April 2018. In addition to control group(120 benign breast tumors) were used for
dtection of BRCA1/BRCA2 mutations in the two groups.PCR amplification by
using(KAPA 2GTMFast Multiplex PCR-Kit),was used for detection of mutation.Results:
From all patients 34(22.7%) have BRCA mutations,16.7% patients with mutations were
indicated to have one mutation in BRCA1"185 del AG or 5382 ins C" , 2.7% were found
to have two mutations in BRCA1" 185 del AG and 5382 ins C",1.3% were verified to
have one mutation "6174 del T" in BRCA2, 2.0% were indicated to have two mutations in
both BRCA1 and BRCA2 "5382 ins C and6174delT",2.5%mutation were presented in
control group.BRCA1"5382 ins C" mutation presented in 61.77% in ages less than 45
years,while BRCA2 "6174del T" was observed in 5.88% patients of ages higher 45 years.
Conclusion: In Iraq, the frequency of breast cancer was presented in high percent in
southern governorate than middle governorate due to They have the characteristics of
significantly high frequency of family history,environmental factor high grade and
advanced The BRCA1 (5382insC) mutations were percent than BRCA2.
... The African Sahel has been a very controversial region in the climatic change debate during the last decades. From the studies that announced a dramatic advance of the desert in the 1970s [Lamprey 1975] and lead to the first conference about desertification [Nairobi, 1977] to the hopeful articles assuming a global recovery from the great droughts of the 70s and 80s [Prince et al., 1998;Hermann et al., 2005], many works have been carried out about this region. The studies of recent years are often characterized by their emphasis in the analysis of climatic fluctuations, specifically inter-annual and inter-decadal variations, as it is necessary to avoid misinterpretations related to climatic variability. ...
... These events clearly contributed to putting this region in the international spotlight and helped to raise awareness of land degradation problem since the 70s (Veron et al., 2006). Some studies pointed out then to an irreversible and advancing desertification in the whole region (Lamprey, 1975). However, the return to wetter conditions in the 90s led to revising previous evaluations and a regreening narrative emerged (Nicholson et al., 1998;Prince et al., 1998). ...
Article publié en anglais (p. 48-51), avec 2 planches hors-texte (p. 80-81)
... Variations in annual rainfall amounts and vegetation cover were cited as a evidence, that the African Sahara desert was shifting southwards caused by human activities. Lamprey [37] for instance, was among the early empirical adherents of this hypothesis; he claimed that the Sahara Desert had shifted some 90-100 km southwards in the north Kordafan region of Sudan between 1958 and 1975. The socalled Charney"s hypothesis [38] argued, also, that reduction in Sahel rainfall were a result of human activities: the systematic and irreversible degradation and desertification of the zone through overgrazing and deforestation and inefficient land-use practices. ...
... In Nigeria, for example, Adetunji 2006, Baka and Jajere (2010in Sawa and Adebayo 2015, Emodu 2013, Haruna and Bukar 2010, Olaganju and Temidayo 2015and Nich (2012in Umar 2015 have all posited that desertification is occurring especially in the semi-arid environment adjoining the Sahara desert in northern Nigeria. Some of these researchers have made use of such statements as "desert is encroaching at the rate of 5.5km per annum (Lamprey 1975); desert is expanding at 6km per annum and 70% of all drylands is affected by desertification (UNEP 1992); desertification shows an increase from 48 to 117 hectares of lands from 1984 -1991" and so on to describe the environmental condition in Nigeria. All of the above statements demonstrate how serious the phenomenon is in Nigeria. ...
... The Sahelian belt has been identified as a "hot spot" of global environmental change and has been the focus of much scientific attention in recent decades spurred by the chronic vulnerability of its population to recurring drought and the threat of long-term land degradation. After a dry period with prolonged droughts in the 1970s and 1980s, many scientists flagged large areas of the Sahel as irreversibly degraded land (Lamprey, 1988;Ayoub, 1998;Dregne, 2002). Recent scientific results suggest that the decades of abnormally dry conditions in the Sahel, which caused an apparently irreversible degradation, have been reversed by positive anomalies in rainfall (Hermann et al., 2005;Ali and Lebel, 2009;Fensholt and Rasmussen, 2011;Brandt et al., 2015). ...
Remote sensing digital image analysis has been applied to monitor land clearing and degradation processes on a plateau covered by tiger bush near Niamey in South West Niger, where signs of severe landscape degradation due to fuelwood supply have been observed in the last decades. A MODIS NDVI dataset (2000–2015) and five LANDSAT images (1986–2012) were used to identify spatial and temporal dynamics and to emphasize areas of greater degradation. The study indicates that the land clearing found by previous investigations in the second part of the 20th century is still ongoing, with a decreasing trend of MODIS NDVI values recorded in the period 2000–2015. This trend appeared to be linked to an increase in bare soil areas that was demonstrated by analysis of LANDSAT SAVI images. The investigation also indicated that rates of degradation are stronger in more deteriorated areas like those located nearer Niamey; degradation patterns also tend to increase from the inner areas to the edges of the plateau. These results attest to the urgency to develop effective environmental preservation policies and find alternative solutions for domestic energy supply.
... Remote sensing, digital image processing, and spatial analysis have proven to be useful technologies in both assessing and monitoring environmental change ( Sun et al., 2005). Since the 1970s, many scholars have initiated a series of desertification studies using remote sensing, in which Landsat TM, ETM, MSS, MODIS, NOAA/AVHRR and SPOT images have been widely used for desertification monitoring ( Lamprey, 1975;Reining, 1978;Peterson et al., 1987;FAO, 1984;Askolla and Hirscheider, 1990;Qi and Cai, 2007; Helldén and Tottrup, 2008;Yin et al., 2011;Reiche et al., 2012). In many studies, Landsat TM, ETM, and MSS were used to develop visual interpretation methods to monitor the desertification process. ...
Aeolian desertification is one of the most significant environmental and socio-economic problems, represents a major component of land degradation, and seriously harms the ecological environment, leading to adverse impacts on human society. Monitoring aeolian desertification and identifying the driving factors behind it are crucial for developing prevention and management strategies to combat this issue. The objectives of this study were to monitor the trends of aeolian desertification in Horqin Sandy Land by using time-series MODIS-NDVI remote sensing data for the period of 2000–2013. A dimidiate pixel model was chosen to calculate the Vegetation Coverage Index (VCI), while a unary linear regression analysis was used for a temporal trend analysis of the Aeolian Desertification Index (ADI) and selected climate factors. The Sen's slope estimator and the Mann-Kendall statistical test were used to analyze the spatial trends of the ADI. (1) The temporal trend of ADI showed three stages: reversion during the period of 2000–2005 and 2009–2013, and development during the period of 2005–2009. For the five classes of ADI, the areas of non-aeolian desertified lands (N) showed an increasing trend and the slight (SL), moderate (M), serious (S), and very serious aeolian desertified lands (VS) showed decreasing trends, with the decline in areas of SL and M contributing to the reversion of aeolian desertification. (2) The spatial distribution showed that the VS was mainly distributed in the southwestern portion, and the S was mainly distributed around the VS portion. The SL and M formed a straight line from the southwest to the northeast, bisecting the two areas of S. The N was mainly distributed in the northwestern portion and the eastern edges of the study area. (3) The spatial trends showed that areas of decreasing and significantly decreasing ADI trends occupied 78.44%, while areas with increasing and significantly increasing ADI trends only occupied 21.56% of the study area over the period of 2000–2013, indicating that aeolian desertification in Horqin Sandy Land is decreasing overall and advancing in certain portions. (4) The driving factors of aeolian desertification were analyzed from the perspectives of two groups: climate and anthropogenic factors. We found that the desertification control measures and favorable climate condition have played key roles in the process of desertification reversion; and climate fluctuations, reclamation and livestock pressure have led to the desertification development. The results can provide meaningful information for the prevention and control of aeolian desertification in Horqin Sandy Land.
... Since the 1970ies, widespread degradation and desertification have dominated the scientific and political debate leading to terms like the Sahel Syndrome, thus loosening the formerly quite rigid spatial fixation (e.g. Glantz, 1987;Lamprey, 1988;Eckholm & Brown, 1977;Wissenschaftlicher Beirat der Bundesregierung Globale Umweltveränderungen (WBGU), 1997;Petschel-Held et al., 1999;Tucker, Dregne, & Newcomb, 1991). International programs like the UNCCD: UN Convention to Combat Desertification, 2015); were initiated and efforts on a regional scale were implemented and supported to combat desertification and to improve the livelihoods of people affected by degradation (Owen, 1979). ...
In recent years, many regions in sub-Saharan Africa have experienced growing contestations of existing livelihood practices and massive environmental change. This has been accompanied by what has sometimes been described as a ‘respacing’ of Africa, i.e. an increasing blurriness of the nation state and social relationships becoming more and more interconnected on the local to global scales, rendering conventional concepts of space and territory obsolete. In this introductory essay, we briefly discuss notions of this ‘respacing’ process, highlight its validity but also its ambiguity, and thus lay the ground for the ensuing compilation of papers on social, environmental, and spatial change in sub-Saharan Africa.
... As a dynamic arid and semi-arid ecosystem, it is known to be sensitive to environmental factors. The Sahel was struck by devastating droughts in the 1970s and 1980s which were previously thought to be the result of past land degradation caused by human activity (e.g overgrazing, wood exploitation)(Lamprey 1988;Mensching 1990). However, as research and monitoring on the area increased, mainly attributed to the ready availability of satellite data, many studies found a significant link between reduced rainfall and vegetation condition(Anyamba and Tucker 2005; Malo and Nicholson 1990). ...
The Normalized Vegetation Difference Index (NDVI) is frequently used as a surrogate for vegetation properties and is often correlated with climatic variables such as rainfall. However, studies have shown that conventional regression models used to study the spatial relationship between NDVI and rainfall are often plagued by non-stationarity and are scale dependent. This thesis employed a spatial disaggregation modelling technique to tackle this issue – Geographically Weighted Regression (GWR) allows measured relationships to vary in space. GWR was applied in the Sahel of Africa for the growing seasons of 2002 and 2012 (June-September).
The results highlighted areas which were particularly sensitive to variations in rainfall and which seemingly form large clusters that connect humid and arid climatic zones. In these areas, rainfall appears to be the dominant determinant in understanding the distribution of vegetation. Moreover, regions mainly located around wetlands were shown to have a very weak relationship with rainfall indicating the need for incorporating additional variables to explain the NDVI variation. Finally, temporal variations were showcased as the spatial relationships would often change from a drier year to a more humid one.
In comparison with traditional linear regression modelling such as Ordinary Least Squares (OLS), GWR model performed significantly better in both years, by producing more accurate predictions, reducing autocorrelation in the regression residuals and allowing for local inferences to be made due to a large output from GWR results being a set of maps showcasing the local situation between NDVI and rainfall. The results were validated by conventional regression diagnostics and local tests to assess the significance and degree of non-stationarity in the data. Therefore, GWR is suggested as an accurate, informative technique both for exploratory and explanatory reasons to treat non-stationarity in heterogeneous areas in an ecological context.
... Commensurate with these changes in land use and with the drought were catastrophic reductions in crop yields and rangeland carrying capacity (Nicholson 1978;Lamb 1983;Hiernaux et al. 2009b). Sahel precipitation anomalies The resulting famines of the 1970s and 1980s plus anecdotal accounts of progressive southwards march of the Sahara desert (Norman 1987;Lamprey 1988) led to the widely accepted narrative that population growth drives cropland expansion, overgrazing and infrastructure extension and that these changes in land use have resulted in widespread land degradation (e.g. Le Houérou 1996;Le Houérou 2002). ...
There is a great deal of debate on the extent, causes and even the reality of land degradation in the Sahel. On one hand, extrapolations from field-scale studies suggest widespread and serious reductions in biological productivity threatening the livelihoods of many communities. On the other hand, coarse resolution remote sensing studies consistently reveal a net increase in vegetation production exceeding that expected from the recovery of rainfall following the extreme droughts of the 1970s and 1980s, thus challenging the notion of widespread, subcontinental-scale degradation. Yet, the spatial variations in the rates of vegetation recovery are not fully explained by rainfall trends which suggest additional causative factors. In this dissertation, it is hypothesized that in addition to rainfall other climatic variables and anthropogenic uses of the land have had measurable impacts on vegetation production. It was found that over most of the Sahel, the interannual variability in growing season sum NDVI (used as a proxy of vegetation productivity) was strongly related to rainfall, humidity and temperature while the relationship with rainfall alone was generally weaker. The climate- sum NDVI relationships were used to predict potential NDVI; that is the NDVI expected in response to climate variability alone excluding any human-induced changes in productivity. The differences between predicted and observed NDVI were regressed against time to detect any long term (positive or negative) trends in vegetation productivity. It was found that over most of the Sahel the trends either exceeded or did not significantly depart from what is expected from the trends in climate. However, substantial and spatially contiguous areas (~8% of the total area of the Sahel) were characterized by significant negative trends. To test whether the negative trends were in fact human-induced, they were compared with the available data on population density, land use pressures and land biophysical properties that determine the susceptibility of land to degradation. It was found that the spatial variations in the trends of the residuals were not only well explained by the multiplicity of land use pressures but also by the geography of soil properties and percentage tree cover.
... The spatial variations in the trends of the residuals were partly related to soils and tree cover, but also to several anthropogenic pressures. of land degradation (e.g., [10][11][12]). These, plus anecdotal accounts of a progressive southwards march of the Sahara Desert [13,14], led to the popular view that population growth in the predominantly agrarian economies of the Sahelian countries was causing an extension of cultivation into marginal lands, shortened fallow periods, increased grazing intensity, and increased fuel-wood extraction, and that these population pressures coupled with the prolonged drought had caused widespread land degradation [15]. ...
There is a great deal of debate on the extent, causes, and even the reality of land degradation in the Sahel. Investigations carried out before approximately 2000 using remote sensing data suggest widespread reductions in biological productivity, while studies extending beyond 2000 consistently reveal a net increase in vegetation production, strongly related to the recovery of rainfall following the extreme droughts of the 1970s and 1980s, and thus challenging the notion of widespread, long-term, subcontinental-scale degradation. Yet, the spatial variations in the rates of vegetation recovery are not fully explained by rainfall trends. It is hypothesized that, in addition to rainfall, other meteorological variables and human land use have contributed to vegetation dynamics. Throughout most of the Sahel, the interannual variability in growing season ΣNDVIgs (measured from satellites, used as a proxy of vegetation productivity) was strongly related to rainfall, humidity, and temperature (mean r² = 0.67), but with rainfall alone was weaker (mean r² = 0.41). The mean and upper 95th quantile (UQ) rates of change in SNDVIgs in response to climate were used to predict potential ΣNDVIgs-that is, the ΣNDVIgs expected in response to climate variability alone, excluding any anthropogenic effects. The differences between predicted and observed ΣNDVIgs were regressed against time to detect any long-term (positive or negative) trends in vegetation productivity. Over most of the Sahel, the trends did not significantly depart from what is expected from the trends in meteorological variables. However, substantial and spatially contiguous areas (~8% of the total area of the Sahel) were characterized by negative, and, in some areas, positive trends. To explore whether the negative trends were human-induced, they were compared with the available data of population density, land use, and land biophysical properties that are known to affect the susceptibility of land to degradation. The spatial variations in the trends of the residuals were partly related to soils and tree cover, but also to several anthropogenic pressures.
... In addition to a large-scale famine relief effort across much of the region, international preoccupation with desertification in the Sahel grew throughout the 1970s, part of a wider growth in concerns about human impacts on the environment which started with the United Nations Educational, Scientific and Cultural Organization's (UNESCO) first Biosphere Conference in Paris in 1968. The international political and institutional response to the drought was spearheaded by of a set of United Nations (UN) reviews of the state of scientific knowledge about the causes and effects of desertification in drylands across the world (see, for example , Lamprey 1975;UN 1977). This period, culminating in the UN Conference on Desertification (UNCOD) in 1977, can be characterized by the consolidation of what Hajer (1995) describes as a 'discourse coalition'-a group of actors, usually with a bureaucratic base, who share a similar set of stories that account for why a particular phenomenon exists and what should be done about it. ...
For nearly a century, crisis narratives about desertification have dominated policy discourse on the Sahelian drylands. This chapter looks at some of the ways in which these have shaped policy interventions in the drylands over the decades, and how contemporary development thinking offers better options for resilient dryland livelihoods. We argue that solutions to the environmental and economic problems faced by dryland systems—especially in the context of climate change—need to be more firmly rooted in a nuanced understanding of ecological change and the links between climate, vegetation and people. They must also involve a shift in power to local people, recognizing the value of marrying modern science with indigenous knowledge systems. Dryland peoples are more likely to prosper when governments reverse heavy-handed attempts to manage these areas. Greater promise lies with decentralizing power and decision-making to local institutions, and recognizing local tenure rights and systems for securing access to land.
... The more humid part of the country contains a variety of vegetation types from savannah to broken woodland and tropical forests [36]. Based on the rainfall variation and the soil properties, Harrison and Jackson (1958) have described the vegetation of the Sudan in five ecological zones; namely: Desert, Semi-desert, Woodland Savannah, Flood region, and Mountain vegetation [37][38][39][40][41][42]. ...
Daily dynamic vegetation cover mapping at the global scale is the most important parameter to retrieve from coarse-spatial resolution global land surface optical satellite remote sensing to understand the climate change impact on the rainfall cycle and its variability in time. The objective of this research was the investigation of the change in vegetation cover dynamic in time and its relationship with rainfall in Central regions of Sudan for a decade (2000-2010). To achieve our objective, the Normalized Difference Vegetation Index (NDVI) time series obtained from SPOT-VGT sensor, precipitation data measured over the study area by different weather stations, GIS and statistical analysis were used. The obtained results show significant level of agreement between NDVI and rainfall values during the study period (0.6 ≤ R2 ≤ 0.8). Certainly, such derived results could be useful as imputing in the carbon cycle models and/or climate impact modeling, as well the development of new policy for climate change adaptation.
... The area selected for the remote sensing pilot test was located within the savannah belt between latitudes 10° 00′ N and 14° 00′ N. In 1972 the Sudanese government in cooperation with FAO carried out the Savannah Development Project for reconnaissance of land and water resources in the southern part of this selected area. For this purpose FAO requested imagery which was obtained by Landsat According to Baumer (1979) and Lampery (1975), the desert was continuing to move southwards at a rate of 5-6 km per year. The studies stated also that desertification is spreading like cancer in other areas including the adjacent low rainfall savanna and that it is quite clear desert encroachment in theses areas is mainly a man-made phenomenon caused by the misuse of land. ...
Desertification is land degradation in arid, semiarid, and dry subhumid areas resulting from various factors. It is a multifaceted phenomenon caused by complex interactions of a number of physical, biological, political, social, cultural, and economic factors impacting the socioeconomic conditions of millions living in the drylands. Desertification is one of the major global environmental as well as developmental issues largely because of its impact on agriculture growth, food production, and rural livelihoods. Though the phenomenon of desertification is very old, the scientific understanding of it and the efforts made to address it are recent. Today communities all over the world have taken various measures to combat desertification under the framework of the United Nations Convention to Combat Desertification (UNCCD). Overall, there is insufficient evidence to show the extent of progress that has been made in combating desertification. In some of the areas, the progress, or lack of it, has yet to be determined.
Wind erosion and salt-affected soils are predominant desertification processes in Sudan, particularly in the northern part, and have adverse impacts on agricultural lands in the arid and semi-arid lands characterized by erratic rainfall, high temperature, high wind velocity and consequent high rates of evapotranspiration. The main objective of this paper is to present research review on combating, control, reclamation and management practices in areas affected by wind erosion and salt-affected soils. The study showed that the principal measures for controlling wind erosion depends on minimizing certain conditions that can be accelerated wind erosivity (winds ≥ 5.4 m/sec) and vice versa maximizing soil erodibility by creation a suitable condition for generate of non-erodible soil particles (NEP) versus soil surface detachment and transport by wind. Wind erosion research requires high financial support, thus this cost should be borne by government. The strategy of management practices of salt-affected soils aimed to sustain a level of salinity tolerable to the cultivated crops through good manages to water and crop. Assessment and mapping of wind erosion and salt-affected soils is urgent need to determine the inherent risk in the affected areas included in investment map of agricultural land capabilities of the country. Encourage studies on stabilizing soil particles by various natural or synthetic cementing and flocculation materials which are friendly to soil environment to increase NEP on the soil surface. Practical programs on reclamation of salt-affected soils should be included in national development programs and national strategy for scientific research in the State.
Apart from inducing unusually high atmospheric CO2 growth rates in productive regions, and its other far-reaching long-term impacts on ecophysiology and ecosystem dynamics, drought events are the world’s most costly natural disasters. The United States, for example, suffered agricultural losses estimated at 40 and 30 billion due to the 1988 and 2012 extreme drought events, respectively. The overarching complexities of drought make it difficult to predict and accurately assess its causes, intensity, duration, magnitude and impacts (e.g., extents) on several spatio-temporal scales. This chapter explores a satellite remote sensing monitoring perspective and a range of multivariate framework and geospatial tools that underpin accurate assessment of the role of global climate teleconnection patterns.
Desertification has become one of the most pronounced ecological disasters, affecting arid and semi-arid areas of Nigeria. This phenomenon is more pronounced in the northern region, particularly the eleven frontline states of Nigeria, sharing borders with the Niger Republic. This has been attributed to a range of natural and anthropogenic factors. Rampant felling of trees for fuelwood, unsustainable agriculture, overgrazing, coupled with unfavourable climatic conditions are among the key factors that aggravate the desertification phenomenon. This study applied geospatial analysis to explore land use/land cover changes and detect major conversions from ecologically active land covers to sand dunes. Results indicate that areas covered by sand dunes (a major indicator of desertification) have doubled over the 25 years under consideration (1990 to 2015). Even though 0.71 km2 of dunes was converted to vegetation, indicative of the success of various international, national, local and individual afforestation efforts, conversely about 10.1 km2 of vegetation were converted to sand dunes, implying around 14 times more deforestation compared to afforestation. On average, our results revealed that the sand dune in the study area is progressing at a mean annual rate of 15.2 km2 annually. The land cover conversion within the 25-year study period was from vegetated land to farmlands. Comparing the progression of a sand dune with climate records of the study area and examining the relationship between indicators of climate change and desertification suggested a mismatch between both processes, as increasing rainfall and lower temperatures observed in 1994, 2005, 2012, and 2014 did not translate into positive feedbacks for desertification in the study area. Likewise, the mean annual Normalized Difference Vegetation Index (NDVI) from 2000 to 2015 shows a deviation between vegetation peaks, mean temperatures and rainfall. On average, our results reveal that the sand dune is progressing at a mean annual rate of about 15.2 km2 in the study area. Based on this study’s land cover change, trend and conversion assessment, visual reconciliation of climate records of land cover data, statistical analysis, observations from ground-truthing, as well as previous literature, it can be inferred that desertification in Nigeria is less a function of climate change, but more a product of human activities driven by poverty, population growth and failed government policies. Further projections by this study also reveal a high probability of more farmlands being converted to sand dunes by the years 2030 and 2045 if current practices prevail.
Desertification has become one of the most pronounced ecological disasters, affecting arid and semi-arid areas of Nigeria. This phenomenon is more pronounced in the northern region, particularly the eleven frontline states of Nigeria, sharing borders with the Niger Republic. This has been attributed to a range of natural and anthropogenic factors. Rampant felling of trees for fuelwood, unsustainable agriculture, overgrazing, coupled with unfavourable climatic conditions are among the key factors that aggravate the desertification phenomenon. This study applied geospatial analysis to explore land use/land cover changes and detect major conversions from ecologically active land covers to sand dunes. Results indicate that areas covered by sand dunes (a major indicator of desertification) have doubled over the 25 years under consideration (1990 to 2015). Even though 0.71 km2 of dunes was converted to vegetation, indicative of the success of various international, national, local and individual afforestation efforts, conversely about 10.1 km2 of vegetation were converted to sand dunes, implying around 14 times more deforestation compared to afforestation. On average, our results revealed that the sand dune in the study area is progressing at a mean annual rate of 15.2 km2 annually. The land cover conversion within the 25-year study period was from vegetated land to farmlands. Comparing the progression of a sand dune with climate records of the study area and examining the relationship between indicators of climate change and desertification suggested a mismatch between both processes, as increasing rainfall and lower temperatures observed in 1994, 2005, 2012, and 2014 did not translate into positive feedbacks for desertification in the study area. Likewise, the mean annual Normalized Difference Vegetation Index (NDVI) from 2000 to 2015 shows a deviation between vegetation peaks, mean temperatures and rainfall. On average, our results reveal that the sand dune is progressing at a mean annual rate of about 15.2 km2 in the study area. Based on this study’s land cover change, trend and conversion assessment, visual reconciliation of climate records of land cover data, statistical analysis, observations from ground-truthing, as well as previous literature, it can be inferred that desertification in Nigeria is less a function of climate change, but more a product of human activities driven by poverty, population growth and failed government policies. Further projections by this study also reveal a high probability of more farmlands being converted to sand dunes by the years 2030 and 2045 if current practices prevail.
The paper covers successful efforts to combat desertification and restore degraded land. It aims to present some of the established practices in combating desertification in Sudan. The paper benefited from the useful accumulated literature and author's own experience in this field, which extended over 40 years as forest field practitioner. The paper reviews the findings of some long-term studies of drylands management in Sudan and other African countries of the Sahel. The causes of desertification in Sudan are as indicated in the literature are mainly due to human activities and climatic variation. Desertification accelerated by different drivers such as the pressure from population growth, economic development under and above ground, over-grazing, over-cutting of fuel wood, deforestation and destruction of forests and range lands, Unsustainable and inappropriate farming systems on fragile areas. In reviewing successful drylands projects and stories, the paper finds the following common themes and lessons learnt: The importance of studying the socioeconomics of land degradation and land rehabilitation and examine the environmental impact of land degradation Usefulness of Involvement of stakeholders Adoption of appropriate intervention for combating desertification Successful stories and programs have often built on local knowledge and experience contributed to accelerating the spreading of best practices. Deforestation and forest degradation are in fact the major threats to the forestry development in Sudan. The sharing and exchange of knowledge and information between different institutions on these practices will be very valuable to boost the efforts for controlling desertification in the country. Based on the set of conclusions drawn, recommendations and guidelines on the development and management of forests and other natural resources as measures for combating desertification are provided.
Controversies surrounding socio-environmental changes and landscape dynamics in Dogon country (Mali)
This article, using the analysis of changes in the Dogon country (Mali), examines the catastrophic descriptions of the evolution dynamics of West African landscapes and environment. Studies on those dynamics, which are frequently characterised as desertification, relies on inappropriate bases. Our aim is not to deny the material reality of the degradation and its consequences on the communities but to throw light on the transformation processes with a different perspective and thus help to reinvent the definitions of the so-called ecosystem restoration and protection programs which, through their simplistic practices, help to increase the vulnerable nature of the socioecological systems that they wish to sustain.
Problem statement: Sudan is the largest (2.5 million km2) country most seriously affected by desertification in Africa. The arid and semi-arid lands cover an area of 1.78 million km2, which represents about 72% of the country’s total area1. Sudan has collaborated with and contributed to the International efforts to combat desertification. It is one of the first countries that signed the United Nations Convection to Combat Desertification (UNCCD) and assigned the National Drought and Desertification Control Unit (NDDCU) for the coordination of programmes to mitigate the effects of drought and to combat desertification as a focal point. Since the 1930s, programmes to combat desertification and its component projects and interventions have been launched in Sudan through technical and financial assistance (local and international) to improve land resources, production systems, and protection of the environment. Sudan, like other African countries, needs plant cover: an earlier study for the UN Food and Agriculture Organization (FAO) indicated that Sudan has lost between 250,000 and 1,250,000 hectares of the total area of its forests since 2005; this is the main reason for the expansion of the desertification phenomenon. Therefore, unless serious and immediate action is pursued, the gap between the sustainability of resources and the degree of exploitation will widen further2. Objectives: The objective of this paper is to review the efforts taken by Sudan in combating desertification from governmental and private sectors, and to assess the reasons for the failure of past efforts to combat desertification. Methodology: Previous acts and agreements from National and International sources have been collected. The hazards of desertification and their impacts on economic and social lives have been evaluated. Findings: Many conclusions and lessons emerged from previous experiences of government, NGOs, civil society and private sectors in implementing desertification programmes in Sudan. The analytical review of Sudan desertification policies showed a lack of an intersectoral approach that integrates forestry activities and land use into the social, economic and developmental process of the country. They also lacked linkages to other sectors that use and actually compete for the available natural resources. Values: Therefore it was recommended that capacity building, public awareness, and integration of NGOs, governmental sectors including research institutions, ministries and international organisations is urgently needed.
Keywords: Sudan; desertification; conflicts; environment
Desertification is land degradation in arid, semiarid, and dry subhumid areas resulting from various factors. It is a multifaceted phenomenon caused by complex interactions of a number of physical, biological, political, social, cultural, and economic factors impacting the socioeconomic conditions of millions living in the drylands. Desertification is one of the major global environmental as well as developmental issues largely because of its impact on agriculture growth, food production, and rural livelihoods. Though the phenomenon of desertification is very old, the scientific understanding of, and the efforts made to address it, are recent. Today, communities all over the world have taken various measures to combat desertification under the framework of the UN Convention to Combat Desertification (UNCCD). Overall, there is insufficient evidence to show the extent of progress that has been made in combating desertification. In some of the areas, the progress, or lack thereof, has yet to be determined.
12. Trasgredire i limiti. Gli spazi LGBTIA
1. Gli spazi LGBTIA
2. Gli spazi LGBTIA come superamento dei limiti degli spazi
eteronormativi
3. La trasgressione dei limiti nello spazio pubblico eteronormativo:
la spiaggia gay naturista
4. Conclusioni
Land degradation is one of the most serious global environmental issues of our time (Dregne and Chou 1994; UNCED 1992). It has been estimated that over 250 million people are directly affected by desertification, and some one billion people in over 100 countries are at risk (Adger et al. 2000). Land degradation has a broad range of definitions that essentially describe circumstances of reduced biological productivity of the land (UNCCD 1999).
The opening chapters of this book examine something that never occurred but was widely believed to have existed—the late 20th century desertification crisis in the Sahel. Recent advances in climatology and changing weather patterns have effectively terminated further scientific debate about the existence of widespread Sahelian desertification, providing us with an opportunity to take stock and draw lessons. The logical and empirical shortcomings of the concept of desertification have been known for decades but the idea has been institutionalized at the global level and is remarkably resilient. The middle section of this book presents new reasons for concluding that the concept of desertification is no longer analytically useful and that we should instead struggle to better define and measure dryland degradation. The closing chapters of the book provide case studies from around the world that examine the use and relevance of the desertification concept. Despite an increasingly sophisticated understanding of dryland environments and societies, the uses now being made of the desertification concept in parts of Asia exhibit many of the shortcomings of earlier work done in Africa. It took scientists more than three decades to transform a perceived desertification crisis in the Sahel into a non-event. This book is an effort to critically examine that experience and accelerate the learning process in other parts of the world.
Key paradigm changes are discernible in the science of desertification or land degradation in the West African Sahel. These have been characterized as a shift from a ‘desertification’ to a ‘resilience’ paradigm. The first of these positions, based on an equilibrial model of social-ecological systems, refers to a range of measurable changes which are unilinear with a strong likelihood of irreversibility. The second is based on a disequilibrial model which begins with evidence for sustainable practices under local knowledge and management of variability. Whereas the desertification paradigm attempts to correct misuse through exogenous interventions, designed to transform natural resource management by improved technologies, the resilience paradigm, based on optimizing endogenous capacities, offers an evolutionary trajectory of development adapted to the constraints of small-scale farming and pastoralism. Guided by this distinction, the complexity and variability of the social-environmental systems in the Sahel are disaggregated under the following headings: bio-productivity changes as reflected in remote sensing; rangeland management; deforestation (the expansion of cultivation, burning, fuelwood cutting and the transition to sustainable practice); and soil nutrient management. Against the backdrop of rapid demographic change, poverty reduction and adaptive capacity are briefly reviewed. An ‘escape from Malthus’ is being attempted through a smallholder intensification pathway in situ and an income diversification pathway that extends to non-local opportunities. Governments, donors, and other agencies can use these as a platform for policies and interventions.
The main objective of this study is to monitor and map the changes on rainfall in central Sudan. A provisional collection of thematic maps from various sources at different scales(this includes isohyets maps of Sudan for the periods (1930 -1960 and 1961- 1990). Precipitation data for the period 1990 to 2010 were obtained from Sudan Meteorological Authority. The results revealed the overall trend observed during the last 50 years indicating a clear change in the Annual average rainfall values, the mean rainfall have decreased when compared with the long mean rainfall (1960 -2000). An average decrease between 0.8 – 78 mm was observed. Rainfall reduction has been severe in semi-arid zone that resulted in the retreat of Desert and Semi-Desert boundary southward with an average of 63 Km reaching up to 179 Km in Central Sudan and North Kordofan.
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