Avaliação hidrogeológica quali-quantitativa do aquífero fraturado serra geral, da cidade de Chapecó (SC)

Abstract

The existing deep well systems in the municipality of Chapecó (SC) have been widely used as a water source for public, industrial, and agricultural supply in the region, becoming crucial for local water security and supplementing potential deficiencies in the public water network. This study aimed to analyze data from tubular wells in the urban area of Chapecó (SC), focusing on the interpretation of hydrodynamic and hydrochemical parameters, providing a detailed assessment to assist in the sustainable management of this resource. The hydrodynamic study of the wells was based on drilling records and registration of 394 wells used for public water supply and installed in the Serra Geral Formation. The data were provided by CPRM and the drilling company Leão Poços Artesianos LTDA. According to the results, the number of drillings increased significantly from 1987 onwards. Groundwater exploitation in the Serra Geral Aquifer System (SASG) varies considerably in the city, with flow rates ranging from 0.5 to 60.9 m3 /h. However, 75% of the wells had flow rates of up to 12 m3 /h. Well depths also vary from 54 to 932m, and in the central zone of the city, static water levels are deeper, ranging from 55 to 163 m. Regarding Specific Capacity, 75% of the wells had values of up to 1.3 m3 /h/m, with 0.32 m3 /h/m as the median for 100% of the sample set. The study also found that the water is predominantly sodic-bicarbonate (40%) and weakly sodic, with low salinity. Out of 394 analyzed wells, 42% had parameters with values above the Maximum Permissible Values (MPV) for human consumption, such as pH, which exceeded 9 in 32.7% of the wells. The application of this study aims to contribute to the sustainable management of this resource in the medium and long term, enabling its judicious, regulated use based on knowledge of the local technical characteristics of the system, to continue contributing to the city's development.