Groundwater fluxes in arid and semi-arid environments

Abstract

In arid and semi-arid areas groundwater fluxes such as recharge and groundwater evapotranspiration are substantially different than in moderate a climates. Rainfall, if present is intensive and occurs in short, spatio-temporally variable events. This results in substantially more spatio-temporally variable recharge pattern than in moderate climates. In arid and semi, in contrast to moderate climates also the importance of groundwater evapotranspiration (ETg) is significantly higher. This is because: a) recharge and therefore entire ground- large water deficit at the surface and shallow subsurface, results in common water flux input is low so then even low contributions of (ETg) are significant; b) groundwater uptake (groundwater transpiration) by plant (mostly tree) roots and bygroundwater evaporation through vapor and capillary upward water movement.