Estudo da vulnerabilidade das águas subterrâneas no município de Santa Rosa/RS

Abstract

Water resources have been constantly affected by several factors. Aquifers, although appearing to be more protected, are also targets of activities carried out of the earth’s surface. Territorial disorder and the inappropriate use of the physical environment favor the degradation of natural resources and especially water quality. Due to the importance of preserving these ecosystems, knowing the natural vulnerability of aquifers and highlighting the risks of contamination to which they are subjected, this study was developed. Therefore, the objective was to calculate, evaluate and map the vulnerability index of groundwater in the coverage area of the municipality of Santa Rosa, located in the State of Rio Grande do Sul. The methodological procedures adopted, started with a theoretical basis on groundwater, and later, about the characteristics of the municipality. The vulnerability was determined using the Method GOD (Groundwater hydraulic confinement, Overlying strata, Depth to groundwater table), a simple technique in which the name represents three parameters in English. Through the SIAGAS platform - Groundwater Information System, data were collected from seventy groundwater captation wells belonging to Santa Rosa and the GOD Method was applied. It was observed that most of the wells, 87,14%, are in areas with insignificant vulnerability class, 10% are in areas of low vulnerability and 2,86% in areas of medium vulnerability, which is justified by the characteristics aquifer and local. However, some attention is still needed, as the results do not mean that the underground water sources are not susceptible to negative impacts. The cartographic representation of the natural vulnerability of aquifers proves to be a valuable instrument, since it points out which regions are more and less appropriate for the installation of captation wells and even new activities. The present study can serve as a subsidy to managing bodies for the preservation of these local natural resources.