Simulation of transient groundwater flow using the analytic element method: development of new analytical solutions

Abstract

The Guarani Aquifer System (SAG, in Portugese) is an important groundwater reserve. In Brazil, it is estimated that 1,443 municipalities are located in the area of the SAG (BORGHETTI et al., 2004), constituting an area of great economic importance and presenting various uses such as urban, industrial and rural. The Ribeirão da Onça watershed is located in the outcrop area of the Guarani Aquifer, in the state of São Paulo (Brotas-SP). Since 2004 the hydrological monitoring is conducted in the watershed aiming to understand the processes of groundwater recharge and runoff in outcrop areas of the SAG (WENDLAND et al., 2007, LUCAS et al., 2012). In this context, this project aims to develop analytical and computational tools, based on the Analytic Element Method (AEM), to simulate the time dependent groundwater flow in the area of occurrence of the SAG. The AEM is a computational method based on the superposition of analytical expressions and has no need for discretization and limitations imposed by boundaries. However, continuous analytical solutions in space and time are currently being developed (STRACK et al., 2013), a subject in which the tenderer intends to contribute during the sabbatical period. The testing and validation of the developed continuous analytical solutions will be realized in comparison to transient data (potentiometric surface variation) observed in the monitoring wells at the Ribeirão da Onça watershed. The experimental results obtained in this area and developed methodology should be extrapolated to the whole area of occurrence of the Guarani Aquifer System. (AU)