Environmental Degradation of Natural Resources in Butana Area of Sudan

Abstract

Environmental degradation has become a very serious problem in Africa since the Sahelian drought. It refers to the diminishment of local ecosystem or the biosphere as a whole due to human activity or the climate factors. Butana, in the north-eastern part of Sudan is known by many nomadic tribes as a good palatable grazing area during and after the rainy season. Rainfall plays a dominant role in the vegetation growth of the area. The goal of this study is to monitor the extent and severity of environmental degradation in relation to climate variability and change. The rainfall time series (1940–2004) for four weather stations were examined on monthly and annual bases to investigate any possible trends. The analysis of rainfall showed gradual decrease in the rainfall for the whole duration of the study at three out of the four stations. The progressive decline in the rainfall since late 1960s was significant and cannot be considered random for the northern part of the area. A significant increase in temperature, in autumn, is partly due to dry conditions observed since the late 1960s. Satellite image was used for routine natural resource monitoring and mapping land degradation. The Moving Standard Deviation Index (MSDI) increased considerably from 1987 to 2000 and the Bare Soil Index (BSI) for the degraded sites increased from 0–8 in 1987 to 32–40 in 2000. The BSI image difference indicated that the index increased between 14 and 43 over the 13 years. It is therefore, observed that different ecosystems in Butana area were subjected to various forms of site degradation, which led to sand encroachment, acceleration of dunes development and increased water erosion in the northern part of the area. The area has also, been subjected to vegetation cover transformation that made the pastures to deteriorate seriously in quality and quantity; however, in many parts of the area, the degradation is still reversible if land use and water point sites are organized.