Hydrofaciologic characterization and water level monitoring in the Guarani Aquifer System in the Araraquara city – SP

Abstract

The Guarani Aquifer System (GAS) is one of the most important hydrostratigraphic unit from South America, and groundwater is highly explored in the São Paulo State (BR). This current study aimed to characterize the hydrostratigraphic framework of GAS in the city of Araraquara, and evaluate the drawdown of water levels in the aquifer through the automated and continuous monitoring in an abandoned well located in the central region of the city. In the study area were recognized three geological formations: Pirambóia, Botucatu and Serra Geral. Four Hydrofacies were characterized: A, B and C, representing the Pirambóia Formation and D the Botucatu Formation. After 710 days it was observed a total drawdown of 4.98 m on the monitored well and the contribution of each well was estimated using the Cooper-Jacob equation. The calculated drawdown was 4.96 m using the historical average flow rates for each pumping well. Wells with maximum distance of 4200m had higher contribution to the drawdown.

Keywords

• Sistema Aquífero Guarani. Águas Subterrâneas. Arcabouço Hidroestratigráfico. Monitoramento de Nível D’água. Araraquara.