Using water budget and computational modeling to estimate groundwater recharge

Abstract

Groundwater is the main water source in several countries and regions in South America and Brazil. However, the overexploitation in some regions exceeds the aquifer’s replenishment capacity, resulting in the lowering of the water table. Thus, it is paramount that the use of these water resources are manage properly, assuring future availability. To that end, the groundwater flow and recharge rates need to be assessed. In this study, groundwater recharge estimated based on the water balance in the unsaturated zone is assessed. Firstly, this approach is evaluated by comparing its results with the Water Table Fluctuation method. Then, the recharge estimates are used as inputs in a transient groundwater flow model and resulting simulated water levels are compared to monitoring. The results suggest that the adopted approach leads to satisfactory results and, despite some inheriting limitations, it has the advantage of being less data demanding than other techniques.