Assessment and Evaluation of Groundwater Resources in Abu Habil Watershed North Kordofan State- Western Sudan

Abstract

Abstract This study is done to study the groundwater resources in north Kordofan state between longitude 29° 30' to 32° 50' E and latitude 12°00 to 13° 40'N. The purpose of the study is to investigate and evaluate the groundwater in the khor Abu Habil drainage basin. it’s about 1000 Km length and cover an area of approximately 6000 Kmz. The geological unites in the study area are; the basement complex, sedimentary rocks. The sedimentary rocks include : Nubian sandstone, Um Ruwaba Formations and superficial deposits (clayey plains and sand dunes). The rainfall range between 682mm and 310mm per years, and decrease from the west to the North and Northeast. For remote sensing studies the Land - sat Thematic Mapper (TM) is used to hydrogeological map preprations. It is evidaent that these integrated study techniques are usefull recormaissance method for water resources studies. The geophysical methods applied are Electrical Resistivity Method - Vertical- Electrical Sounding (VES) and horizontal electrical profile (HEP), to determine the groundwater occurance, aquifers extensions, thickness and depths and calbrated with borehole lithological data. The hydrogeological setting can be identified by two aquifers types : The shallow aquifer, these include the upper Umm Ruwaba aquifer, Wadies, and sand dunes aquifers. Thes group is considerd as perched water, the depth to the water level range between 2 meters to 30 meters from the surfac land. And the other group - Deep Um Ruwaba aquifer is the main aquifer in the area. The water table of deep aquifer range from 71 meters to 87 meters from the subsurface land. The chemical analysis for water samples to determine the suitability of groundwater for human consumption and agricultural purposes according to (WHO) standards. The Sodium Adsorpation-Ratio diagram (SAR) is used to determine the groundwater suitability for agricultural uses. The chemical investigation shows that they are two types of groundwater facies: Sulphate - Chloride - Calcium - Magnessium and Bicarbonate - Sodium - Potassium facies. According to The total dissolvid solid (TDS) values in water, water resources can be classified in to two types, type of (TDS) <1000 ppm (fresh water used as drinking water) and‘ type of (TDS) > 1000 (Brackish water used for agricultural purposes).