Geocomputação aplicada no problema de transporte acoplado ao fluxo subterrâneo em aquífero livre

Geocomputation, being the application of computational methods and techniques to support the resolution of georeferenced problems, helps the understanding of natural phenomena related to water resources. Some geoprocessing tools provide digital maps that delimit the watershed under study, and the potentiometric distribution in known coordinates in the computational domain can be used in the initial and boundary condition of the hydrogeological model. In this sense, the article aims to implement geocomputing techniques in solving the problem of contaminant transport in phreatic aquifer. The proposed approach methodology begins in the generation of an unstructured mesh; generates the function for the boundary condition; applies a Picard iteration method with a numerically calculated initial estimate; simulates the groundwater velocity field in pumping wells and recharge areas situations and, finally, couples the stationary and nonlinear phreatic flow solution, obtained by the finite element method, to the advective and dispersive parameters of the transient contaminant transport equation. Graphic results illustrate the simulation of hydraulic behaviour and concentration isolines in georeferenced subsurface of the Lobo Reservoir watershed in the municipality of Itirapina-SP.