Estudo comparativo dos métodos de cálculo de recarga no aquífero freático da Região Metropolitana do Grande Maputo

Abstract

This scientific project focused on estimating the recharge of the region's groundwater aquifer. metropolitan area of ​​greater Maputo, where two methods were used: the balance method based on real precipitation and evapotranspiration data that was calculated using the Thornthwaite formula, for the years (1940-2000) which corresponds to 60 hydrological years and the water table variation method using data from 11 piezometers for the period (2015- 2019) corresponding to 4 years. The water balance method indicated for the study period a annual deficit of 73.6 to 159.6mm/year, predominantly in the months of April to November and excess that varies from 23.9 to 39.3mm/year distributed in the months of February to March. For the groundwater table variation method, an average specific yield of 0.21 to 0.27 was adopted considering the average of fine, medium and coarse sand deposits, according to the classification from Morris and Johnson (1967), the average values ​​of annual recharge varied from 56.2 to 215 mm/year. The results obtained from this research were useful for understanding the behavior of free aquifer system in greater Maputo, assisting in water management processes underground. (TRADUÇÃO NOSSA)