Simulação de fluxo unidimensional em aquíferos aluviais com barragens submersas.

Abstract

An alluvial aquifer near the city of Santa Luzia in the state of Paraiba was chosen to study the effects of subsurface darns during the drought period from 1998 to 1999 in order to establish a numerical model to simulate the interactions among them under groundwater flow conditions. The alluvial deposit in study varies from 50 m to 400 m in width and 1 m to 10 m in depth with an extension of about 5 km. Based on these geomorphological properties, which are typical for alluvials in the semi-arid region of Northeast of Brazil, an one-dimensional model was developed including the inclination of the crystalline bedrock and the behavior of the observed water table near the subsurface dams was modeled. Three different situations w<ere simulated: An alluvial aquifer without any dam, with one dam and with two dams placed in its course. The first two cases were fictitious situations for the alluvial aquifer in study. From the results of these simulations it was possible to evaluate the effects of the dams on the groundwater flow with regard to the drained and storaged water volumes during a 2 years period. The results of the simulations encourage the employment of subsurface dams placed at adequate sites in alluvial aquifers with similiar hydrogeological properties as the studied one.