Modélisation de l'impact des activités anthropiques sur les nappes phréatiques côtières Cas de Chott Maria (Sahel tunisien)

Modeling of anthropic activities impact on coastal aquifers: case of Chott Maria

¹ Ecole Nationale d'Ingénieurs de Sfax, Tunisie
² Division des Ressources en Eau du CRDA de Sousse, Tunisie

Abstract

Chott-Maria's aquifer is recharged by precipitation, but also by non-treated waste-water injection through abandoned wells, partial infiltration of irrigation waters brought from the North, and treated waste waters used to irrigate gardens and golf playing-fields. Due to the urban extension, the pumping activity has moved from South to North but it has not quantitatively diminished and the risk of marine-water intrusion has not been discarded. Currently, the recharge by anthropic water injections constitute a hydraulic barrier against this marine-water intrusion. The mathematical modeling showed that the generalisation of the collective drain-network, by 2001, should be preceded by a redistribution, in space and time, of the pumping areas and rates. Otherwise, a marine-water intrusion with a width of 3 km would affect the northern sea-coast since 2006.