Conceptos básicos sobre o papel ambiental das águas subterrâneas e os efeitos da sua explotaçao

摘要: Groundwater is an essential part of the hydrological cycle. It characterized by long residence time, ubiquity and small variability. Chemical, flow characteristics properties have to be considered taking into account three-dimensional behavior system. The stable variability chemical a fundamental role in geological biological processes and, as consequence, they important environmental implications, such sustaining river spring base flow, wetlands, phreatophyte plant communities, gallery forests, �, also they are satisfy human needs. The use groundwater implies changing flow pattern, which may result water-table piezometric level drawdown, decrease water discharge, composition changes, besides subsidence some cases. All this modify conditions, leading decrease, plant surface area, drying wetlands modifications related changes. However, these appear longdelayed and at very slow pace. Even case-effect relationships not easily seen. Negative impacts compared to social benefits from development other alternatives. This includes possible remediation of negative delayed effects their costs. Aquifer salinization contamination issue taken account, since groundwater will soon or later contact environment with it contaminants.