| With the speedy development of city economy, constant rising of population and swiftness of citified process, geological issue of city environment becomes more extrusive and the problem of city water supply and need and groundwater pollution becomes more and more serious. Water source crisis and conflict between water supply and demand are pricked up, which affects industrial and agriculture directly and harm ecological environment and people's health. Lijiang is where tour world culture inheritance "Lijiang Ancient City" and world memory inheritance locates on, and is main part of world nature inheritance "three-parallel-river belt", which has become the most attracting and developing foreground. Lack of water source and pollution of groundwater will be very serious of this region. Exploiting, managing and protecting groundwater properly have been the urgent demand of Lijiang economic development. So it has great meaning to perform study on water source and groundwater vulnerability and provide scientific rules for groundwater's proper developing and managing. The main content of this paper is as follows:1. General study situation of city home and aboard environment geology, water source and groundwater vulnerability;2. The changing of water source quantity and influence factor of Lijiang;3. Based on geology, physiognomy and hydrogeology and natural and society environment and Lijiang Basin changing rule of level of the fourth series fleet layer pore water, the polluting status and reason of city groundwater is analyzed.4. Estimate groundwater vulnerability of Lijiang according to DRASTIC index.5. Water source developing actuality and attenuation and shortage trend of city water demanding and supplying in the future of Lijiang city;Such conclusions are obtained:(1) Water of run-off river mainly comes from atmosphere precipitation of Lijiang basin, which is not equal in dry and wet seasons, and change of water source and precipitation are consistent. Year rainfall is affected by temperature largely, which generally is the contrary rule. Since 1997, amount of rainfall and evaporation maintains rising trend, and the latter is more distinct.(2) Water quality actuality of surface water in Lijiang City: quality of northern part(water resource) general belongs to the first rank, and general estimate result is good;quality of southern part belongs to the fifth rank, and general estimate result is seriously polluted;city zone of Lijiang is the main polluting resource of surface water.(3) Quality of Karst spring ground water generally belongs to I rank, which is not polluted. However, surface water of city zone is seriously polluted, which is closely related to pore water in the fourth series (fleet level) in runoff, surface sewage and ground pore water replenish to one another frequently. In this way, big area pore water is polluted in runoff direction.(4) According to DRASTIC evaluation system, the vulnerability index distribution value of Lijiang basin city is 82-204, mainly between 136 and 204, and generally belongs to middle rank. The easiest to be polluted area is 39.5 km2(25.8%),the higher area is 112.2km2(73.2%).At the same time, there is potential human environment influence factor. Therefore, while considering the project construction, seriously polluted program should be avoided;and the protection of water resource, important karst spring, water supplying district and sight water must be enhanced.(5) From the analysis of water's demanding and supplying of Lijiang basin, water quantity can only meet the demand of near future and metaphase development, but not sufficient for the far future. Climate in Lijiang is warm and dry, and use of water is not proper, pollution is serious, rate of using and supply ability of water are low, which leads to the evident water shortage in Lijiang City. Sustainable using measure of water is proposed in this paper. |
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