Groundwater resources in a semi-arid area: a case study from central Sudan

Hydrogeological investigations were carried out to evaluate the groundwater resources in the northern part of the Khartoum Basin, central Sudan. The hydrogeological system consists of two aquifers. The upper aquifer includes mainly the Upper Gezira Formation, the upper part of the Lower Gezira Formation in the area between the two Niles, and the uppermost parts of the Lower Omdurman Formation in other areas of the study region. The lower aquifer is developed mainly in the other deeper sedimentary sequences. The sedimentological characteristics of the host formations appear to have affected the physico-chemical properties of the two aquifers in different ways. The grain size and pumping test analyses indicate the higher productivity of the lower aquifer, where the water storage is approximately eight times as much as the upper one. Except in a few parts of the upper aquifer, groundwater in the study area is free from objectionable properties in relation to drinking and irrigation demands. (C) 1997 Elsevier Science Limited.