Influência da interação rio-aquífero na disponibilidade hídrica fluvial. Estudo de caso: Rio Itapicuru - Ba

Abstract

The growing demand for water resources puts pressure on ecosystems rivers, which suffer the impacts of disorderly removals in the matrices surface and underground. Considering that the flow present in rivers is a result of the surface runoff and baseflow portions, this study aims to evaluate the river-aquifer interaction, in the portion of the Tucano aquifer, existing in the Itapicuru river, considering the effects on river water availability for meeting the potential demands of multiple uses of water. From this perspective, the area was characterized in terms of climate, soil and hydrogeological, as well as well records and surface demands and underground. Furthermore, the rainfall pattern and the behavior the river regime; base flow separation methods were applied; hydrogeological recharge was estimated using two methods and was developed water balance considering a scenario of potential demands to the basin. The results showed changes in the fluvial regime of the Itapicuru river, the anticipation of floods and reduction of their magnitude by, approximately 50.61%; the recharge balance showed a contribution from rainfall in the recharge of the free aquifer especially between the months of May and June; The baseflow separation returned a baseflow index (BFI) above 0.60 for the stretches studied and the water balance for the evaluated scenario presented, for the most recent time frame, the need to exploit 4.26 m³/s of exploitable reserve 72.22% of the time to meet demands. In this perspective, the integrated management of water resources is seen as the path to guarantee of environmental sustainability.