The role of superficial geology in controlling groundwater recharge in the weathered crystalline basement of semi-arid Tanzania

Little Kinyasungwe River Catchment, central semi-arid Tanzania. The structure and hydraulic properties of superficial geology can play a crucial role in controlling groundwater recharge drylands. However, the pathways by which occurs their sensitivity to environmental change remain poorly resolved. Geophysical surveys using Electrical Resistivity Tomography (ERT) were conducted study region used delineate shallow subsurface stratigraphy conjunction with borehole logs. Based on these results, series local-scale conceptual hydrogeological models was produced collated generate 3D model wellfield. We propose that configurations control dryland settings as follows: 1) sand deposits act collectors stores slowly feed into zones active faulting; 2) fault provide permeable enabling greater occur; 3) ‘windows’ within layers smectitic clay underlie ephemeral streams may for focused via transmission losses; 4) overbank flooding during high intensity precipitation events increases probability activating such pathways. These physical basis improve numerical drylands, framework evaluate strategies (e.g., Managed Aquifer Recharge) artificially enhance availability resources regions.