Groundwater Pollution Risk Sources Identification And Zoning Of Prevention And Control In Plain Terrain Of Beijing

Effective identification of groundwater pollution resources and classification has great significance on the identification of groundwater pollution risk and prevention and control zoning of groundwater pollution.By analyzing main groundwater pollution sources in plain terrain of Beijing,a quantitative calculation method of the pollution sources hazard based on representative characteristics of pollutants attribute and pollutant emission amount was built in this research.The ARCGIS 9.3 software was used to perform overlay analysis of the distribution characteristic of the pollution loads and contaminants properties in plain terrain of Beijing,achieving the identification of pollution resources and pollution resources classification.On this basis,groundwater pollution risk assessment was performed combined with groundwater vulnerability assessment.Then groundwater pollution prevention and control of zoning was completed combined with comprehensive consideration of the groundwater quality,pollution current situation of groundwater resources,exploitable quantity and water protection zone delineation.Meanwhile,in order to get more accurate groundwater pollution prevention and control division,sensitivity analysis was done by changing weights of characteristics of pollutants attribute and the prevention and control division index.Main conclusions obtained from this paper are as follows:(1)The results of groundwater pollution source classification make clear that this method can relatively accurately reflect hazardous classification of pollution sources,and the results show that industrial pollution sources to groundwater pollution in plain terrain of Beijing made the greatest contribution,followed by urban residential areas and garbage dumps.The highest level of groundwater pollution risk is situated in capital iron factory in Shijingshan district.(2)The results of zoning map of groundwater pollution prevention and control show that the area of the highest prevention and control grade in plain terrain of Beijing are mostly situated in the west of eight districts of the city and the north and northeast of the plain terrain.The groundwater pollution risk grade,groundwater value grade and groundwater source protection zone grade in these regions are all at a high level;the districts of comparatively low prevention and control grade are mostly situated in the center,southwest and northeast of the plain terrain.Overall,zoning map of groundwater pollution prevention and control in plain terrain of Beijing can synthetically reflects the current groundwater situation in this region from the point of view of the essence,social economy and policy.Being in line with the actual situation,it can also provide basis for the actual work in the next step.(3)Uncertainty analysis results show that the prevention and control division index weights are more sensitive than the characteristic of pollutants attribute weights.The characteristic of pollutants attribute weights are the parameters in the evaluation process of potential hazardness of the sources of pollution,belonging to the lowest level of the whole evaluation system,while prevention and control zoning index weights for the evaluation are the parameters of the ultimate prevention and control of zoning,belonging to the highest level of the entire evaluation system.This uncertain result is mainly from the characteristics of the three levels constructed by the method.For this reason,it is particularly important to reasonably determine groundwater risk,self-value of groundwater and groundwater source protection zone weight.