Assessment of Groundwater Vulnerability to Pollution in the Metro Hilir Watershed Using the SINTACS Method

Abstract

Assessment of groundwater vulnerability in the Metro Hilir watershed is necessary because most people use well water to meet basic needs. Identification and spatial analysis are the first steps to determine the potential for groundwater pollution in the area. The SINTACS method was used to assess the intrinsic vulnerability of groundwater using the parameters of groundwater table depth, effective infiltration, material in the unsaturated zone, soil texture type, aquifer media, hydraulic conductivity, and slope. Data processing was carried out by using Geographic Information System (GIS) techniques. Weight scenarios was used based on the hydrological conditions of the study area, namely “Normal Impact” and “Drainage/seepage”. The SINTACS index results was classified into several levels of vulnerability. The high vulnerability class is spread across the east to the south side, while the low vulnerability class is more dominant in the western area. The results of Sensitivity Analysis using the Map Removal technique showed that in both scenarios, soil texture parameters have the highest variation index value of 1.73% in the “Normal Impact” scenario and 2.13% in the “Drainage/Seepage” scenario. Parameters with high variation index values have a sensitive influence on vulnerability class values.