AQUIFER POLLUTION VULNERABILITY OF THE SANTA MARIA WATERSHED, RIO GRANDE DO SUL STATE, BRAZIL

With the increasing pollution of surface water resources, groundwater consumption has grown rapidly in recent times. It is a resource that most often does not require treatment for human consumption. From this, there are some tools that aim to assist in the management of those groundwater resources. This paper aims to evaluate the natural vulnerability of aquifer to contamination in the watershed of the Santa Maria River, within the Parana Sedimentary basin in the Rio Grande do Sul State, southern Brazil. The GOD scheme was applied to determine the aquifer pollution vulnerability. Results indicate a moderate vulnerability for ca. 31.89% of the area, and a high vulnerability for 50.44% of the total area. These natural characteristics were related with the predominance of porous/permeable sandstones in its substrate constitution and the occurrence of shallow groundwater levels. This geologic context makes the aquifer more vulnerable according to GOD scheme. These results are important for the management of groundwater resources, uses in municipal master plans and land use.