Geophysical Assessment of Groundwater Reservoir Characteristics of Shagera Basin

By: Sulieman Ahmed Hamid Fadul

Abstract:

This work focuses on the groundwater investigation of the Shagera basin in north Darfur state with the objective of subsurface geology study, evaluation of groundwater study and determination of water bearing formations and expected groundwater depth using geophysical methods (VES) A total of (8) request sites were investigated.  These sites are considered to have sufficient groundwater potential to justify drilling boreholes and enable to understand Hydrology, Hydrogeology of the study area-groundwater occurs in Nubian Sandstone aquifer as the main aquifer in the basin and under artesian conditions.  However, groundwater is also stored in small amounts in superficial deposits, in jointed volcanic and from weathered Basement  Complex.  In Nubian Sandstone, groundwater is 50m below the ground level, this is evidence from the geoelectrical section and stratigraphical section of the study area.  Leakage occurs from the over lying superficial  deposit aquifer to the Nubian Sandstone direction coinciding with the direction of surface water flow of Wadi El Ku.  The mean value of transmissivity  of the Nubian aquifer is about (4200)m/d, while the coefficient of storage is 2*10^-2.  TDS and some ions such as nitrates and chlorite increase in the direction of groundwater flow mainly after the rainy season.  Groundwater from the Nubian Sandstone and Superficial deposits is fresh water and is chemically fit for drinking purposes as well as for irrigation.

Groundwater from the weathered Basement Complex, which is associated with chlorite, is chemically not fit for drinking purposes.