Study On Security System Of Lake Reservoir Water Sources In City Based On GIS

Drinking water safety is the foundation of the city security and plays an importantrole of the sustainable development. Lake reservoirs is main type of centralized drinkingwater sources in our country. Scientific and reasonable environmental protection on thequality of the water is very important and urgent to promote safe urban sustainabledevelopment and the construction of a harmonious society. This paper first choosed theShaba reservoir in drinking water sources as the research object, and established theodor foundation database. And then extracted basin characteristics through the ArcGIShydrologic module analysis, based on this identify pollution the key areas and dividedinto protected area. Finally it studied the key factors which attributed to theenvironment safe and made an analysis on the watershed ecological condition bylandscape pattern evaluation index. The main conclusions as follows:(1)Based on four picture than1:1scale topographic map, It estabilished thedrinking water source of ShaBa reservoir data base. According to certain steps such asvector graphics of grid, image registration, topology generation figure spot, datalayer,the special database has been built by layered formed with data. Attributedatabase has been built though type coding formed by relation database. Multimediadatabase was based on the high resolution images of remote sensing data andon-the-spot investigation photo image data.(2)Based on the digital elevation model of water source basin, It extracted the basinfeature and divided the son river basin through ArcGIS hydrologic module analysis. Theresults show that the river network distribution is most closest to the actual waterextraction when the catchment area threshold reach3000. It was divided into12subordinate basins.(3)This paper analyzed4kinds of pollution include the scope of internal pollution,non-point source pollution, line source pollution and non-point source pollutioncomprehensively, It studied each subordinate basins by pollution comprehensive indexanalysis of the specific pollution and identify the key polluted areas by pollutioncomprehensive index, then the whole basin was divided into the key polluted areas,second polluted areas and normal polluted areas.(4)Obeying to the<Technical Guideline for Delineating Source Water Protection Areas>(HJ/T338-2007) and <Delineating Source Water Protection Areas inChongQing>(ChongQing GOV. Press[2002]83), It delineating the accompanyingpotable water source area the first-grade protection zones, level2reserve and quasiprotected area combined with pollution extent of the key area.(5)It studied the characteristics of internal pollution, point-source pollution,Non-point source pollution comprehensively and put forward the pollution controlmeasures to all kinds of pollution respectively.(6)Based on the landscape pattern evaluation, the conclusion that in recent yearsthe basin of the ecological security comprehensive index is0.9425. It means that Theecological security of whole basin is good, Suggestions for the development ofecological water source has been provided through the analysis.