Impacts of Climate, Topograpy and Weathearing profile on Hydrogeology and Water Resources Assesment in Semi Arid Terrain. Using Earth Observation1 ALI, ASTERDEM and GIS techniques

The demands of growing populations in semiarid regions feed a continual need to locate new ground water resources and to explore other unconventional water supply options. Locating ground water is especially critical as such regions are normally characterized by low and highly variable rainfall, high temperatures, low humidity, high rates of potential evapotranspiration and the near absence of permanent surface water. The purpose of this study is to the use of space technology and Geographic Information System GIS, which are applied to identify the hard rock aquifer characteristics in Semiarid terrain. The study area is highly fractured and undulating crystalline terrain. Hence, satellite images of Landsat 7 ETM+ and EOALI were processed using ERDAS Imagine software, among whichthe major elements controlling ground water accumulation and flow were determined. Various digital enhancements and hyper spectral techniques are applied to extract the Litho Structures, weathering profiles, soil types and land cover types. A combination of Spectral information from Landsat ETM+ data plus spatial information from ASTERDEM data is used to address the topographical variations in the study area. All these elements were manipulated in GIS system, and each of them was given a certain rate of effectiveness. Final maps are describing. The research results could provide effective tools for the hydrology research, and support the sustainable water resources development and management in a rid regions.