Research Of Groundwater Vulnerability Assessment And Pollution Prevention And Treatment Regionalization In North China Plain

Groundwater vulnerability assessment, pollution risk assessment and pollution prevention and treatment regionalization are important basis for protecting groundwater resources. Carrying out the research is of great significance in north China Plain, for it is a place that water shortages, groundwater is the main source of water supply and facing pollution risk. This research can provide evidence for land use planning, protection of water resources planning, groundwater quality monitoring and play a guiding and exempling role for other areas.The paper discusses the basic concepts and research methods of groundwater vulnerability and pollution risk systematically, introduces the natural, socio-economical and hydrogeology characteristics of the research area. And the paper does groundwater vulnerability assessment, pollution risk assessment and pollution prevention and treatment regionalization of North China Plain by making full use of the survey data and research results of previous project.First, the improved DRASTIC model was used to assess groundwater intrinsic vulnerability of 1959, 1984 and 2005 in North China Plain. The result showing that the high and very high area are mainly distributed in the alluvial-proluvial fan zone of piedmont, eastern part of old yellow river alluvial flatlands and marine plain of old yellow river. From 1959 to 2005, area of very low and low vulnerability expanded and area of moderate, high and very high vulnerability reduced. The study on response of groundwater vulnerability to human activities shows that vulnerability level changes are significant correlation with buried depth changes, while are medium and weak related with changes of unsaturated zone comprehensive lithology and aquifer accumulate thickness of sand layers.Evaluation indexes and grading standard were constructed on the basis of intrinsic vulnerability, and groundwater special vulnerability considering human activity was assessed using fuzzy comprehensive evaluation method. The distribution of organic pollution and chloroform quality grade verified the objective rationality of evaluation result. Comparing with the intrinsic vulnerability results, high and very high area expanded in Beijing and Tianjin, while reduced especially in alluvial-proluvial fan zone of piedmont and recharge area of yellow river. The reason is pollution load decreased the influence of hydrogeology condition to groundwater vulnerability.Regarding special vulnerability as the probability of groundwater pollution and resource function as damage degree, groundwater pollution risk map is obtained by vector superposing special vulnerability and groundwater resource function using matrix method. Groundwater pollution risk assessment is the basis of groundwater pollution prevention and treatment regionalization, area that high risk is just need key protection. Obtain the regionalization map according to the map of groundwater risk assessment and put forward pollution prevention and control measures which provide evidence for groundwater pollution prevention and treatment.