drylands

The interaction between dryland hydrological fluxes and the high spatial and seasonal climate variability is inherently complex. Groundwater recharge is episodic, and rivers are ephemeral. When flow occurs in the river network, water is lost through the riverbed, giving rise to focused recharge, which could be a significant part of total recharge. We have used the integrated and physically based MIKE SHE modelling system to analyze the hydrological processes and fluxes in the 7,715 km2 Hout-Sand catchment in the South African part of the Limpopo River Basin.

Water balance partitioning within dryland intermittent and ephemeral streams controls water availability to riparian ecosystems, the magnitude of peak storm discharge and groundwater replenishment. Poorly understood is how superficial geology can play a role in governing the spatiotemporal complexity in flow processes.