Estimativa da recarga de água subterrânea utilizando o método WTF na porção continental da Bacia Sedimentar de Campos, Rio de Janeiro, Brasil

In the present study, we estimated the recharge of unconfined and shallow aquifers in the continental portion of the Campos Sedimentary Basin, Rio de Janeiro state, Brazil, by applying the WTF method. Except for wells P1 and P2, where the most discrepant values were found, an average recharge of 106.1 mm was recorded, representing 16.5% of the rainfall, to analyzed period. Ten wells selected in the study area had their water level variation monitored for one hydrological year, from October 2015 to September 2016. Rainfall records from three stations, Campos, Farol de Sao Tome, and Sao Francisco de Paula, were processed through WTF. Recharge estimates are an essential consideration for the management of water resources, and it is generally challenging to estimate recharge accurately. The literature describes several methods to quantify groundwater recharge, the Water Table Fluctuation (WTF) method being one of the most widely used, likely due to the relative abundance of available water table variation data, as well as its simplicity and easy application. The recharge results obtained were similar in eight of the ten wells monitored. The WTF method is applicable for regions with climatic characteristics similar to those of the study area, since monitoring continues for an extended period, with daily water level measurements, if possible. The method may contribute to obtaining more reliable results, which will aid decision-makers in managing the aquifer.