Spatial distribution of physicochemical parameters of the Quaternary Aquifer System in Sergipe: a case study at the Sergipe Hydrogeological Research Site (SEHRES) in São Cristóvão/SE

Abstract

The physicochemical characterization of groundwater is an essential approach for understanding the regional and local hydrogeochemistry of aquifers, detecting contaminations, and assessing environmental impacts. The use of multiparameter probes allows for rapid, reliable in-situ measurements, making them excellent instruments for monitoring the quality of groundwater and the conditions of wells and aquifers, thereby supporting the water management of a region. This unprecedented study in the region consists of a preliminary survey of physicochemical parameters in 15 tubular wells located on the UFS Campus in São Cristóvão, SE, chosen for already constituting a network for periodic monitoring of groundwater levels. This study area was named SEHRES (Sergipe Hydrogeological Research Site) and the groundwater quality study was conducted through field surveys equipped with a continuously monitoring multiparameter probe, YSI EXO 1 model, properly calibrated. This probe was selected for its ability to provide a comprehensive characterization of the physicochemical attributes of the water and support the detection of potential contaminations. It features multiple sensors that instantly measure parameters such as temperature, salinity, dissolved oxygen (OD), total dissolved solids (TDS), pH, turbidity, and electrical conductivity (EC), with integrated GPS. As a result, GIS-based spatial distribution maps of all measured parameters were produced, allowing for the characterization of the natural conditions of the shallow, porous, and unconfined aquifer, as the detection of potential contaminations and local hydrogeochemistry.