Desertification, a phenomenon referring to land degradation in arid, semi-arid and dry sub-humid regions as a result of climatic variations and human activities, is considered as one of the most severe environmental and socio-economic problems of recent times. The principal aim of this study was to explore the impacts of desertification, degradation and drought on both the natural resources and man's livelihood in the Sudan and to suggest appropriate forest resource management interventions. The study was based on a fact finding tour in the Sudan and data collection on drought trends as reflected in rainfall trends in the study area, and on trends concerning the productivity of natural resources. Information was also compiled from existing records on rainfall, forest land cover, forest stocking, rangelands and carrying capacity and on agricultural productivity and population trends. Results showed that in rain-fed agricultural zones in the Sudan, deep ploughing and leveling of the surface soil caused an increase in its susceptibility to wind erosion, which, in turn, has led to a severe decline in its fertility and, in some places, the formation of sand dunes. The implications of these trends on the natural resource base include environmental degradation, food insecurity and aggravation of income inequalities among the Sudanese producers. The study has suggested Agroforestry technology as a potential solution to this continued problem of declining rural agricultural production in the Sudan.
The term Sahel (an Arabic word for shore) is used to refer to the semi-arid zone to the south of Sahara desert. It is one of the world’s warmest regions, with a short summer rainy season of three months[1,2]. Climatologically, the Sahel is characterized by frequent droughts - low, poorly distributed and highly variable monthly and seasonal unpredictable rainfall. Arid, semi-arid and dry sub-humid zones are characterized by, low and erratic rainfall that does not exceed 700mm per annum, periodic droughts, and different combinations of vegetational cover and soils. Inter-annual rainfall varies from 50-100% in the arid zones of the world with averages of up to 350 mm. In the semi-arid zones, inter-annual rainfall varies from 20-50% with averages of up to 700 mm. Regarding livelihoods systems, generally speaking, light pastoral use is possible in arid areas whilst rain-fed agriculture is not usually possible. In semi-arid areas agricultural harvests are likely to be irregular, although grazing is satisfactory[3,4]. The dry sub-humid areas receive higher amounts of rainfall than the other categories of drylands which can reach more than 800 mm annually. Drylands are characterized by high maximum temperatures and large temperature differences between day and night. Other climatic characteristics include strong winds, and low humidity. These are reflected in an increased vapour pressure deficit with implications for water use efficiency, transpiration, and evaporation.
Drylands are frequently subjected to drought which is the main limiting factor on biomass production and crop yields. Human induced factors such as overcultivation, overgrazing and other forms of inappropriate land use, when practiced under the conditions prevailing in the drylands, may result in significant degradation of vegetation and, soil leaching and in many cases, in desertification.
Against this backdrop, this study was conducted to explore the impacts of desertification, degradation and drought on both the natural resources and man's livelihood in the Sudan. Data for this study was derived from both primary data (observation) and secondary data or a review of relevant literature, and a compilation of other available information on drought trends as reflected in rainfall trends in the study area, and on trends concerning the productivity of natural resources in the wider context of land degradation and desertification. Information was also compiled from existing records on rainfall, forest land cover, forest stocking, rangelands and carrying capacity and on agricultural productivity and population trends.