The Research On Water Resources Carrying Capacity Of Changsha City

Water resource plays an extremely important role in the city development. Water resource is the most important condition of city survival, and it is also a determining factor of the urban economy continual increasing and population capacity. Water should be regarded as a basic factor of urban planning and construction. However, current city planning has not pay enough attention to water resources, specially the water resources supporting capacity not yet obtains the correct understanding. This creates water resources supporting capacity can not to adapt with development in certain cities and other kind of water problems. This will definitely hinder the sustainability of social, economic and cultural development, especially for those water scarce cities. Along with the rapid development of economy in China, city scale enlarge constantly, the shortage of water resource has become"the bottleneck"of city development.Based on the basic present situation of metropolis area economy development and the statistical data research analysis for many years, the main tendency and the operating law of social economy in this area has been found. Grey predictive model has been established, with the help of this model, the main indexes of social economy in this area are predicted. The result is that the model's precision is high, and it can be put into practice. The plan has become the basic target in the research of water resources carrying capacity in this area.This paper sets out from the historical and present researches of ecological environmental water requirements and water resources carrying capacity of river basins, analyze the mechanism of ecological environmental water requirements,its components and the calculation methods of all components, and combine with the actual circumstances of Changsha city to calculate approximately ecological environmental water requirements of the river basin, calculate t water resources carrying capacity of the river basin with the model whose only object is to support the threshold people to live.This article embarked from the research history and the research present situation of region ecological environment water demand, analyzes the requirement mechanism the constituent as well as each constituent computational method of metropolis area ecological environment. Combined with the actual circumstance of Changsha city, the region ecological environment water demand has calculated approximately. By the simple target optimization model, the water resources supporting capacity of Changsha city, threshold population of the water resource, was account.The results demonstrate: in the year of 2020, the threshold population of the water resource in Changsha city can support is 170×104, more than the estimated population,390×104, so the water resource supporting capacity in dry spell of Changsha city is not strong, and the seasonal lack of water is serious.