Research On The Shallow Groundwater Functional Zoning Of Jinjiang Based On GIS

Shallow groundwater which exists between the first aquifuge and the first aquifer of the hydrogeological structure refers to the one that buried underground from0to60meters. Generally, shallow groundwater which is characteristic of shallow burial, easily polluted and updates quickly is phreatic water, but sometimes it also includes micro artesian water. Recently, unreasonable development and utilization of shallow groundwater results in numerous environmental problems, which needs functional zoning to guide the process of shallow groundwater development and utilization so as to reach the goal of harmonious coexistence between man and water.The results of groundwater functional assessment are the basis of functional zoning. The functional assessment of the shallow groundwater involves lots of impact factors. On the basis of analysis of the factors that influence and represent the groundwater functions, this paper includes the react factors, status factors and driving factors of the groundwater functions in order to build the assessment index system. Based on the experience and knowledge of experts, this paper screens indexes from the functional factors to build the shallow groundwater functional assessment index system which has three aspects of resources, ecology and geology. The paper determines the weights of the indexes by the introduction of Analysis Hierarchy Process(AHP). The shallow groundwater functional assessment index system has three parts named resources function, ecological function and geological function. Resources functions of shallow groundwater mainly include four aspects which are occupancy, availability, reproducibility and regulatory. Ecological functions mainly include three aspects which are plant, soil and water environment. Geological functions mainly include one aspect:seawater or saltwater intrusion which stands for the failure degeneration of groundwater system.By comparison of comprehensive assessment analysis model, the paper adopts the method named additive composite to build the comprehensive assessment model of the shallow groundwater functions. According to the index system built above, the paper has given the marking table which is used to evaluate the shallow groundwater functions of the study area as the basis of the functional assessment.In consideration of the status of the development and utilization of Jinjiang shallow groundwater, the paper builds the appropriate functional system. After the arrangement of datum and information that is related to Jinjiang, the paper builds attributive and spatial database, subdivides the area according to the administrative boundary, and evaluates the single function and comprehensive function of each evaluative unit. Based on the evaluative results, the paper realizes the shallow groundwater functional zoning of Jinjiang by considering the groundwater functional zoning system which aimed at supporting technical advises for the shallow groundwater using plan made by relevant departments and providing instance for shallow groundwater functional zoning of southern coastal area.