The Study On Vulnerability And Urgency Of Groundwater Based On GIS In Dalian

With the rapid development of urbanization in China, groundwater pollution problem hasbecome increasingly serious, which resulted in a decrease of available water resources,intensified the contradiction between supply and demand of water resources, directlyinfluenced the healthy development of production, living and ecological environment.Analyses on the urgency of groundwater pollution in Dalian city is beneficial to optimizingthe allocation of resources and manpower in the groundwater pollution control, and to makingrelevant departments more efficient on groundwater pollution governance;It also can providea reference for the decision-making in groundwater development and utilization，and achievethe goal of sustainable development.Groundwater quality assessment is a useful method for judging regional groundwaterwater quality conditions. Groundwater pollution evaluation is usually based on the evaluationof groundwater quality. Groundwater vulnerability and the nature of external pollutionsources are two important factors which affect the quality of groundwater. Taking center cityof Dalian as a research area, the urban Groundwater vulnerability and urgency problems arestudied in this study. The main contents are as follows:(1) The research status of groundwater pollution are comprehensively summarized athome and abroad, the methods of groundwater vulnerability evaluation are analyzed, grade ofpollution sources, groundwater quality evaluation and the application of the GIS tools in thevulnerability and quality evaluation of groundwater, probes into the urgency of groundwaterpollution research train of thought.(2) Based on the factor of intrinsic vulnerability which affecting the quality ofgroundwater,221data of the groundwater vulnerability assessment in Dalian. The maturemethod of DRASTIC is used to be the evaluation system, the entropy weight method is usedto allocate the weights, evaluation results are obtained at last. ArcGIS software is used to mapthe partition of the seven index，then maps are combined with space. It is divided into fivelevels according to the results of the vulnerability assessment, and the results are analyzed.(3) From the view point of the release of pollutant sources of pollution factors, a detailedsurvey in the distribution of pollution sources of Dalian city pollution has been done, Thesurvey includes living pollution, the industrial and mining pollution, agriculture and forestrypollution, sewage treatment plants pollution, landfills pollution,seawater intrusion pollution.The simple evaluation method combined with detailed classification method was evaluated.Mapping is studied by using the ArcGIS software, and finally the source classification figureare got, and low, medium and high three levels are divided according to the evaluation results, at last the pollution sources distribution situation are analysed in Dalian.(4) The present situation of groundwater quality in Dalian is evaluated. Firstly, the addnote type rating method is adopted to carry on156data which collected on September in2011in the classification evaluation. Then clustering analysis method is used to carry on theclassification to the evaluation.Finally kriging interpolation method which based on ArcGISsoftware is used to transform156point data into polygon data, get the status of groundwaterquality in Dalian evaluation chart, and analyzes it.(5) The concept of groundwater pollution urgency is discussed in this part, throughcomparing the groundwater vulnerability to pollution source relations have concluded that thegroundwater quality analysis table, then compared with the present situation of groundwaterquality in order to test its feasibility. Municipal groundwater pollution control strategies andsuggestions are put forward by comparing the relationship of the groundwater vulnerabilitymap, pollution sources classification graph and the present condition of the groundwaterquality in Dalian.