Assessment and Mapping of Desertification using Remote Sensing Data and GIS Techniques, River Nile State, Sudan (1985-2016)

Abstract

In Sudan, land desertification (LD) has devastated large areas and consequently, it includes social, economic, and environmental aspects. Remote sensing technology has become unique and developed tool for providing temporal and spatial information for the LD research and other environmental aspects. The study was carried out to derive accurate and improved spatiotemporal information: to assess the status of vegetation and soil, mapping and assessing land desertification during the four decades using appropriate GIS and remote sensing technology. The study used four-cloud free images of different sensors (TM 1985, ETM+ 1995, ASTER 2016 and LDCM 2016). The study area is located in the River Nile State, approximately about 20 km west Almatama town, covering 105000 hectares (250000 feddans). It extends approximately between latitudes 1836000 to 1878500m N and 0476500 to 0522250m E. The imageries were Geo-referenced and radiometrically corrected by using QGIS software. Classification and post classification were used to determine soil unit and land cover classes and to measure the extent of sand dunes during the last 31 years. Then subsets of the study area were taken by using ARC MAP, The study applied the new approach of integration between vegetation and soil indices and in situ data to assess the LD. Secondary data including soil survey, meteorological stations data and land evaluation reports for the study area were used. The study recommended that RS and GIS technology are to be used to provide good results for mapping and assessment of changes in land cover types and land desertification.