Groundwater quality analysis and mapping using GIS techniques: a case study from northwest Türkiye

The İnegöl Plain, located in northwestern Türkiye, suffers from environmental problems such as air, water, and soil pollution due to intensive and uncontrolled human activities. Recently, the availability and quality of groundwater in plains have been adversely affected to an alarming degree. Therefore, it is necessary to determine and map the groundwater quality in the İnegöl Plain. This study aimed to determine and map the groundwater quality in the İnegöl Plain. Within the scope of the study objective, a dataset consisting of analysis results from water samples taken from 107 wells located within the plain boundaries was used. The dataset contained ten different parameters. These data were analyzed using comprehensive statistical methods. These assessments were supported by Geographic Information System (GIS)-based mapping and analytical tools. The results of the study showed that according to the drinking and utility water quality index results of the samples taken from the wells in the plain, the Drinking Water Quality Index (DWQI) (74.8%) and Irrigation Water Quality Index (IWQI) (87.8%) were acceptable. According to these results, it was determined that the DWQI and IWQI classes are weak, very weak, and unsuitable in parts of the plain near the Bursa-İnegöl highway.