Vulnerabilidade de aqüífero na micro região colonial de Santa Rosa – RS

Abstract

This work evaluates the vulnerability of the aquifer in the micro colonial region of Santa Rosa using the GOD methodology and the data from the wells registered in SIAGAS. The region is in the northwest of the state of Rio Grande do Sul and is contained in the Paraná basin. The area belongs to the Serra Geral formation Paranapanema facies, an igneous province comprising large-scale basaltic flows. Locally, there is a predominance of basaltic rocks, which constitute a fractured aquifer, sometimes free and sometimes confined. Groundwater vulnerability was calculated using the parameters geology, aquifer condition and distance from the topographic surface to the water level. The distance parameter ranged from less than 1 meter to 188 meters and a free aquifer with a depth of more than 30 meters was considered free with coverage. Given the geological conditions, depth of the saturated zone and condition of the aquifer, the hypothesis was that there would be a high natural protection. This was partially supported by the results of the aquifer vulnerability of each well calculated, insignificant 65.5%, low 22.5%, average 8.3% and high in 1.3% of the wells. As for the map produced with the minimum curvature interpolator, 51.2% of the area had insignificant vulnerability, 38.3% low, 9.2% medium and 1.3% high. The most vulnerable places are between Santa Rosa and Candido Godói and also between Crissiulmal and Dr. Mauricio Cardoso.