Research And Application Of Comprehensive Index System For Groundwater Exploitation In Pinggu District Of Beijing

Pinggu district is located at the northeast of Beijing downtown. The importance of the location makes this district become a significant joint in the development area of east of Beijing. This area is abundant in water resource, which also makes Pinggu become one of the water supplies in Beijing. However, with the high dependence on the groundwater and the fast urbanization of the city, the public's demand on water resource in Pinggu district is gradually increasing, and the current water supply cannot meet the requirement from modern agriculture, urban industry, tourist industry and the environmental residence in this place. The situation water shortage in this area is at stake. Therefore, it is meaningful to carry out an overall evaluation concerning groundwater exploitation to optimize the appropriate water distribution and implement the groundwater sustainable utilization strategy based on not only the regional characteristics of Ping district but also its present status of groundwater utilization.This study is founded on the analysis of local geography and hydrogeological setting and groundwater exploitation situation of Pinggu district. We apply the theory of systems analysis to the assessment of groundwater utilization of Pinggu district, as well as considering various factors in the frame of rules of Water Permit System, which may affect the assessment result.First of all, we set up a comprehensive index system for the assessment system of groundwater utilization of Pinggu district according to the assessment principle. The proposed index system is composed of three layers, which are objective layer, attribution layer, and essential layer from top to bottom. And we also define 3 evaluation items in attribution layer and 13 other evaluation items in essential layer by the functions of each layer. Subsequently we use the analytic hierarchy process to define the numerical weight for each element in the hierarchy, and assign 5 rankings for the evaluation result calculated by the synthetical index method. These 5 rankings are respectively called suitable exploitation, moderate exploitation, restraining exploitation, limitative exploitation, no exploitation.Finally, we apply the proposed comprehensive index system to the optimization module in the groundwater management system of Pinggu district. This module, based on the proposed analytic hierarchy for the groundwater exploitation and combined with the simulation model of Pinggu district groundwater system, is used to calculates the assessment result and evaluate the influence which different groundwater exploitation plan will exert on the social and economic field, environment and groundwater resource in Pinggu area. The assessment result provided by this optimization module will help the water management department to understand how the effect of different groundwater exploitation might be on the study area, and find out the best exploitation site for their groundwater exploitation scheme. Users could view the outcome of assessment directly by viewing a grid map in form of GIS, which is colored with various hues according to the evaluation rankings.