Innovative Source Tracking of Groundwater Contamination: PMF – Geostatistics Fusion in Human‐Dominated Regions

Accurate identification of groundwater contamination sources is crucial for effective water pollution prevention, yet precise quantitative methods remain limited. This study investigates the sources of groundwater contamination in the Hutuo River area, a region heavily influenced by human activities, using hydrochemical analysis, the positive matrix factorization (PMF) model, and geostatistical methods. The findings reveal that the groundwater is slightly alkaline, with total hardness (TH) and nitrate (NO 3 − ) concentrations exceeding standards at rates of 81.5%–85.2% and 44.4%–59.3%, respectively, indicating significant human impact. Based on hydrochemical methods, it has been identified that SO 4 2− in groundwater primarily originates from the dissolution of gypsum, while Ca 2+ and Mg 2+ mainly come from the dissolution of carbonates. NO 3 − is predominantly sourced from fertilizers and sewage. The PMF model identifies industrial wastewater, domestic sewage, water−rock interactions, and nonpoint source pollution as the primary sources. Domestic and industrial sewage contribute 44.1%, 34.9%, and 28.3% to groundwater pollution during the dry, flood, and normal water seasons, respectively, while industrial sewage contributes 24.1%, 19.2%, and 20.9%. Our research findings provided a scientific basis for preventing the deterioration of groundwater quality and protecting the ecological environment in areas strongly affected by human activities.