ASSESSMENT OF HYDROGEOCHEMISTRY AND GIS-BASED EVOLUTION OF GROUNDWATER QUALITY AND SALINITY IN THE SHALLOW AQUIFER OF SÃO JOSÉ DO NORTE, SOUTHERN BRAZIL

Water salinization changes hydrogeochemistry, affects the quality and quantity of groundwater available for human consumption its mitigation is time-consuming. A large brackish lagoon Atlantic Ocean surround aquifer São José do Norte town (Brazil). Population economic growth demand more domestic agricultural purposes, stressing aquifer. Despise aquifer’s social-economic status, potential impacts on have not yet been substantially investigated. The aims this study were to analyze hydrogeochemistry aquifer, focusing search indicators, assess suitability drinking irrigation purpose. Ionic ratios, Piper USSL diagrams applied, such as new methods, Seawater Intrusion Groundwater Quality Index (GQISWI) (GWQIHC). results showed that mostly calcium bicarbonate type did indicated occurrence. interior northern area had highest ionic content lowest water values. Most samples contained at least one parameter above maximum allowed concentration purpose according standards. High alkalinity, iron hardness reduced consumption, requiring treatment before ingestion.