Determination of Hydrogeological Parameters of Alluvial and Disa Sandstone Aquifers of West Darfur State, Western Sudan

Abstract

The study area concerns with the hydrogeological parameters of the alluvial aquifer and Disa Sandstone aquifer in West Darfur State, western Sudan. The western Darfur region is characterized by steeply slope topography of crystalline basement complexes terrain; hence, the bulk of surface water lost due to surface runoff and evaporation resulted in extremely shortage in water supply. The objectives of the current study are to investigate the water - bearing formations in order to define aquifers parameters and to assess water levels fluctuations in alluvial sedimentary aquifer systems. In this study the determination of hydrogeological parameters of alluvial and Disa Sandstone aquifers supported with the digital image processing of remotely sensed data, GIS - spatial analysis are applied to satisfy the requirements of the objectives. The Disa sandstone Formation covers an area of 300 km2 in West Darfur and extends into Chad. Approximately, the transmissivity values of alluvial deposits vary from 15 m2/d to 32 m2/d and sandstone varies between 15 m2/d, and 32 m2/d with average value of 18 m2/d. The specific yield in the alluvial aquifer ranges between 6% to 28%. The transmissivity (T) for Disa Sandstone is ranging from 17 m2/d to 88 m2/d with average value of 43 m2/d, while the specific yield for this aquifer ranges between 21% and 27% in Disa Sandstone. The boreholes drilled in Disa Sandstone reaches the Basement Rocks at depths range from 70m to 145m from the surface.