Rainfall Erosivity, Land-Use and Land-Cover Change Analysis for Gadarif Region, Sudan

The purpose of this study was to analyze the combined impacts of rainfall erosivity and change in land-use and land-cover (LULC) on land degradation in three sites located in Gadarif region (eastern Sudan). Monthly rainfall dataset (1979 to 2009) were used to compute rainfall erosivity based on the Modified Fournier Index (MFI), while satellite images from three dates were utilized to detect the LULC change by means of the Maximum Likelihood Classification algorithm. The results showed no significant increasing trend in the rainfall and the rainfall erosion power is range from high to very high in the region. The general patterns of LULC change experienced rapid conversions in natural vegetation into mechanised agricultural land which later left as bare land. Land cover changes did not occur at equal rates during all time intervals, i.e. the agricultural land at Gadembaylia site was decreased from 73.31% in 1989 to 57.45% in 2009. While the bare land increased gradually from 12.10%, 20.34% and 38.64% in 1972, 1989 and 2009, respectively. However, the most consistent trend of LULC change was a progressive loss of the natural vegetation cover, between 1972 and 1989; natural vegetation experienced a strong loss at an annual rate ranged from 4.91% and 3.7%. Increasing trend of rainfall erosivity in conjunction with the disappearance of natural vegetation resulted in an accelerated impact on the land degradation in study area. LULC in Gadarif Region, Sudan are undergoing dramatic challenges. Therefore, the results of this study could be beneficial to stakeholders, decision makers and national planners.