Groundwater evapotranspiration - Underestimated component of the groundwater balance in a semi-arid environment - Serowe case, Botswana

摘要

Steady state, quasi transient and true-transient modelling were used to study groundwater balance of the semi-arid Serowe aquifer in Botswana. Special attention was given to the spatial and temporal variations of groundwater evapotranspiration loss and its impact upon groundwater balance. As spatial variable groundwater evapotranspiration was determined through the integration of SEBAL algorithm in the steady state and quasi-transient modelling approach. A one-dimensional lumped model was also used to study the temporal impact of highly variable rainfall upon the effective recharge in true-transient modelling approach. Results of the various methods employed have been compared and evaluated.