Modelagem computacional e anÃlise da salinizaÃÃo dos aqÃÃferos na Ãrea central de Recife

AUTOR(ES)
DATA DE PUBLICAÇÃO

2004

RESUMO

Groundwater is an important water source either for usual exploitation or to be kept as a strategic reserve, regionally and locally, and it needs to be protected. Groundwater quality depends on social and economic activities, depends on land use, and groundwater contamination has become more frequent. Nowadays salinization is the most common type of groundwater contamination, mainly in coastal areas. After it happens, salinization is persistent and difficult to remediate. So, groundwater protection is an important task for a sustainable development. Recife Metropolitan Region (RMR) has a population of 3 millions inhabitants and water demand is roughly 14m3/s. Surface water supplies 8m3/s and groundwater supplies 6m3/s. RMR has increased groundwater exploitation to compensate water shortage from public supply especially in drought periods. Salt concentration increase in RMR aquifer has been a concern since the seventies. Several drilled wells have been abandoned after salinization. RMR water crisis in dry years lead many people to drill their own wells and increase the water extraction. Recife aquifers are overexploited and potentiometric levels have been lowered. Hydraulic gradients changed direction and now it induces sea water landwards. Also there are problems of vertical salt migration from brackish upper aquifers. This work analyses groundwater condition at the plain in Recife central area (coordinates UTM 9107000 to 9112000 North and UTM 289000 to 293500 East). Several well information have been catalogued, lithology sections and potentiometric maps have been drawn, and database also includes hydrochemical analysis, topography, pumping rates, well depths and well locations. Lithological sections have been studied to analyse aquitard discontinuities; and water sample isotope analysis has been carried out. A computational model has been used for a better understanding of aquifer system flow. Capibaribe river, in its last reach, at Recife plain, presents high salt concentration, especially at high tide in dry months. But also in dry months pumping is increased and this induces recharge from river brackish water. This brackish water goes first to the upper aquifer and then to lower aquifer either through aquitard discontinuities or through poorly constructed wells or abandoned wells. A continuous monitoring of the aquifer and of groundwater exploitation is needed to better estimate and control salinization problems in Recife

ASSUNTO(S)

recursos hÃdricos Ãguas subterrÃneas modelagem computacional salinizaÃÃo engenharia civil

ACESSO AO ARTIGO

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