Detecting and Mapping the Influences of Vegetation Cover on Runoff and Torrents in Khartoum State, Sudan

Abstract

The study was carried out in Omdurman and Sharg El-Neel to map and detect how the status of vegetation cover impacts on runoff and torrents. Satellite imageries of Landsat Thematic Mapper (TM) of 1994-2009 and Operational Land Imager/Thermal Infrared Sensor (OLI/TIRS) of 2018 were processed to derive accurate land use and land cover (LULC), using hybrid classification and normalized differences vegetation index (NDVI) of the study area. The results revealed changes in LULC classes during the study period (1994, 2009 and 2018). Omdurman area showed that the vegetation cover for the years 1994, 2009 and 2018 was 3.2%, 3.1% and 4.2% respectively. The respective sandy soil ratio was 18.2%, 34.9% and 27.6%. The water bodies were found to cover only 0.5%, 0.5% and 0.7% respectively. These results indicated that the area of vegetation cover was less than other LULC. Contrary, results from Sharg El-Neel revealed that the percentage of vegetation cover for the years 1994, 2009 and 2018 accounted for 31.4%, 41.3% and 24.7% respectively. The sandy soil ratios for these years were 26.3%, 14.8% and 38.3% respectively. The water bodies covered 0.5%, 0.6% and 1.3% respectively. The research concluded that changes in status of vegetation cover plays a role on water runoff and torrents events in the study areas. Thestudy recommends further studies to help produce robust plans that consist with LULC status, to minimize the water related risks and hazards.