Evaluation of groundwater pollution risk based on the optimized DRASTIC model:A case study of the areas along the route of South-to-North Water Diversion Project in Shandong Province
Based on the requirements of guaranteeing water quality and sustainably developing ecology proposed by the South-to-North Water Diversion Project,the prevention and treatment of groundwater pollution has become a research focus.In this study,the prevention of shallow groundwater pollution along the route of South-to-North Water Diversion Project in Shandong Province was taken as an example,and the system of evaluating shallow groundwater pollution risk in the study area was constructed from the aspects of groundwater pollution source load,groundwater ecological vulnerability and groundwater functional value.The pollution load was quantitatively and qualitatively analyzed in terms of toxicity,emission and emission possibility of pollutants.Based on land use data and soil oxygen contents,an optimized DRASTOL model was constructed after the optimization of a traditional one.Habitat quality data and night light coefficients simulated by the InVEST model,and the sensitive F-and SO42-concentration distributions in groundwater in the study area were used as factors to evaluate the groundwater functional value.The results show low values in both shallow groundwater pollution loads and groundwater functions,and show medium values of groundwater vulnerability.Combined with groundwater pollution load,groundwater vulnerability and groundwater functional value,the distribution of groundwater pollution risk was obtained.The results show that the groundwater pollution risk in the study area is generally at a low or a medium level.The area with high pollution risk totals 7,444.88 km2,accounting for 20.17％of the whole study area,which is mainly distributed in central Heze City,the center and southwest of Jining City,the northwest Zaozhuang City,the center and east of Tai'an City,and the south of Gangcheng City.Reasons for groundwater pollution in these areas mentioned above are as follows.Because groundwater levels in these areas are relatively shallow,when much precipitation occurs in the natural environment,surface pollutants easily infiltrate into the ground,which can pose a threat to the groundwater quality.Besides,industrial and mining land is densely distributed in these areas whose strata are rich in water;consequently,a large number of strong toxic pollutants are likely to be emitted.At the same time,pollutants are also possibly generated by social and economic activities with high intensity.The combined influence of the above factors leads to high risk of groundwater pollution in the study area.The results obtained in this study provide a reference for the zoning of groundwater pollution risk in the areas along the route of South-to-North Water Diversion Project in Shandong Province.
pollution riskpollution loadvulnerabilityfunctional valueSouth-to-North Water Diversion Project
国家科技期刊平台
NSTL
万方数据
