Study On Ecological Water Demand Of West Region Of Chongqing

The economy of west region of Chongqing has been developing rapidly, but because of an uneven distribution of water resources and rare water quantity, water resources problem has a strong impact on social economy and environment of west of Chongqing.The thesis was tried to quantify the amount of water needs for eco-environment conservation and restoration for the region from the aspect of eco-system water demand. The advances of research on eco-water demand were briefly introduced, and then the theoretic foundation and connotation for eco-water demand were discussed in detail. Some famous traditional methods were mentioned with the advantages and shortcoming being given. Considering the current environmental situation of west region of Chongqing, the main environmental problems were analyzed and classified, it was believed these issues could be summed up as: water pollution and excessive groundwater exploitation.Based on the above analysis of ecological problems for the whole region, it was reasonably considered that the eco-water demand of west region of Chongqing should be comprised of in-stream water need and off-stream consumption, the in-stream part included the basic ecological water consumption, the water consumption for transportation of sediments, the river diluting and self-cleaning water demand, the required water for sustaining city rivers and lakes.Referring previous research productions, the basic calculating formulas were established to calculate the eco-water demand for different parts of west region of Chongqing.Besides, given the variability of the discharge amount of population in the future, the author forecasted the self-cleaning water demand from the aspect of pollution load.By calculating the eco-system water demand of Xiao Anxi region,It was conclude that the total number for eco-system water demand is about 0.386 billion m3 for the whole the Xiao Anxi region. Because the eco-system water demand accounts for 61.6 percent of the average annual runoff, according some sources abroad, the water consumption of in-stream in west region of Chongqing is in a very tense circumstance. The main causes are over-exploitation of surface water resources and heavy utilization of eco-water demand for other purposed.