Plain Area Of ​​beijing Groundwater Vulnerability Study

Water resource is an important environmental factor related to human survival closely. In recent years, along with the economic development, population increase and urbanization speeding-up, human demand for groundwater resource of is increasing. Therefore, how to prevent groundwater pollution and to achieve the sustainable exploitation of groundwater resource is very important. Groundwater vulnerability reflects the potential possibility of groundwater system to be polluted. The research of groundwater vulnerability is the basis of groundwater resource protection and draws more attention.The ground water is main source of water supply in Beijing. Of the total water supply for the city, two-thirds are ground water. For the precipitation decrease, the problem of water shortages has become more serious in years past. Facing the shortages of water supply in Beijing, the groundwater resource has been polluted in different degrees. The safety of water supply has been threatened by the pollution, which aggravates water crisis of Beijing. Studying groundwater vulnerability and evaluating groundwater antipollution performances quantitatively have great significance to the groundwater protection in Beijing.The paper discusses the basic concepts and research methods of groundwater vulnerability systematically, introduces the natural, socio-economical and hydrogeological characteristics of the research area. And the paper makes evaluation of the quality with Aggregative Index Number Method based on large amount of data of groundwater. By selecting depth to groundwater, net recharge, aquifer media, soil media, impact of the vadose zone media, conductivity of the aquifer, groundwater quality and groundwater pollution source as the evaluation indexes, determining the weightiness of evaluation index by analytical hierarchy process, the evaluation model of groundwater vulnerability in the influence of human activities is established. On the platform of the ArcGIS software, the author apply the DRASTIC method and the model of groundwater vulnerability in the influence of human activities to evaluate the groundwater vulnerability in Beijing Plain, then get the vulnerability index and final distribution area of groundwater vulnerability. On the whole, the groundwater vulnerability distribution has such a law, weaker from the upper area to middle and lower area of the alluvial fan in Beijing plain. The groundwater environment in Beijing plain is relatively vulnerable; groundwater protection capacity is poor and easily polluted in some areas.The result of research shows that the groundwater vulnerability is in good agreement with spatial distribution of hydrogeological conditions in the research area. The assessment results can reflect the capability of groundwater system to be protected and provide reference for the planning department of the groundwater resource.