Diagnóstico preliminar de vulnerabilidade à contaminação das águas subterrâneas por necrópole em Frederico Westphalen – RS

Abstract

As a result of surface water degradation and high population growth, there has been a significant increase in the use of groundwater to meet consumer demand. This resource is subject to several sources of contamination, such as cemeteries, which if installed without complying with environmental protection measures, release residues from the decomposition of the corpses directly into the soil, and can reach the water table. In this sense, this work aims to evaluate the vulnerability to contamination of groundwater by necropolis in the surroundings of the Municipal Cemetery and the region of Frederico Westphalen, through the application of the GOD methodology. The adopted methodology consisted in the collection of information, data collection and treatment of tubular wells registered in SIAGAS. The results were expressed in maps of topography, soil thickness, static level and dynamic level that correlated, based the map of vulnerability proposed by this work. For the mapping, the QGIS program was used, with IDW interpolator, with factor 6 for distance between points. The correlation was verified that the vulnerability indices are more significant in places that present lower soil thickness, associated to areas with relatively flat relief and shallow static level, as well as areas with intense anthropic activity. Also, it was pointed out that the rainfall index influences the recharge rate of the aquifers as well as facilitates the infiltration of contaminants in the soil. The integration of the results based the classification of the municipal area with 52.67% in the insignificant class, 40.42% with low significance and 6.91% with medium significance. The Municipal Cemetery is located in an area with low and medium vulnerability, but its environment presents areas with potential for contamination. Compared with other work carried out in the area, with the same theme, there was an increase in the size of areas with low and medium vulnerability class in the proposed model. The application of this technique of geoprocessing allowed the survey of areas that need the attention of the public managers and provides subsidies that can be used as a base for the management of the use and occupation of the municipal soil.