The hydrogeologic potential conditioning factors of hydrographic catchments of Upper Velhas River Basin,Southeastern Brazil

The hydrogeologic potential of a drainage catchment represents its capacity of sustainable water production, with good maintenance of the baseflows. In basins of similar shapes and bio-climatic characteristics, the potential will depend on several physical and anthropogenic conditioning factors. The determination of the hydrogeologic potential is a complex procedure, but alternative methods exist, in which hydrologic series are used to determine certain indexes, such as the recession coefficient (α), the specific baseflow (SBF), the baseflow index (BFI), transmissivity and storativity. Aiming at the evaluation of the hydrogeologic potential and its conditioning factors in the Maracujá River Basin (southeastern Brazil), ten catchments were selected and monitored. The catchments have distinct geologic and geomorphologic characteristics but are submitted to similar climatic conditions. The hydrogeologic potential is higher in crystalline basement areas, especially where the relief is flat and the regolith is thick; however, it is lower in the areas affected by gullies. The advantages of the hydrologic method, in particular to regions where information is scarce, are that it is easily applied and of low cost, enabling the characterization of the hydrogeologic potential and contributing to the management of water resources.