Estimating recharge values using hydrochemical and geological data: a case study from the semiarid Kalahari catchment of northern Namibia
Only a spatially distributed approach can sufficiently describe recharge distribution in a large catchment. In this study the decreasing chloride concentration along groundwater flow paths has been used to represent recharge areas within the groundwater basin. Absolute recharge values, derived by application of the chloride balance method in the saturated zone close to the groundwater divide, have been assigned. A total recharge of 2.8 x 108m3year"1 has been evaluated for the Kalahari basin of semiarid northern Namibia draining towards the Okavango-Makgadikgadi System. The Otavi Foreland (Damara Sequence) is the most important hard rock recharge area for this catchment. Most of the recharge areas which feed the groundwater through partly unconsolidated sediments of the Kalahari Group, are restricted to flood courses. Keywords: chloride method, GIS, groundwater, Kalahari, Namibia, recharge, regionalization, semiarid.
Impact of Human Activity on Groundwater Dynamics
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