Identifying spatial heterogeneity of groundwater and its response to anthropogenic activities.

With the rapid development of economy and society, the quality of groundwater is deteriorating under the dual influence of natural factors and anthropogenic factors, and it seriously threatens the safety of human drinking water. Identifying and analyzing the impact of anthropogenic activities is the key to solving this problem. Based on the groundwater problem in Changle County, Shandong Province, P.R. China, 43 groundwater samples were taken and tested. The statistical characteristics of the monitoring data, the groundwater chemical types, spatial distribution of groundwater, and influencing factors were analyzed by using enrichment factor, Mahalanobis distance, grey water footprint, and so on. The analysis results show that the overall water quality of Changle County is poor, and the main over-standard ions are Cl- , SO2- 4, and NO- 3. There is obvious spatial heterogeneity in the groundwater quality. The spatial variation of NO- 3 is affected by structural factors (topography, hydrology, etc.) and random factors (industrial, agricultural, etc.), and the spatial variability of NO- 3 is the most significant. Other water quality indicators are mainly affected by structural factors. The mass concentration of most ions decreases gradually from north to south, and the overall water quality in the southern region is better than that in the northern region. Thus, the supervision of chemical fertilizers and pesticides should be strengthened. The advanced treatment and reuse of wastewater from industrial parks should be promoted to improve the quality of groundwater and ensure the safety of human drinking water.