The Runoff Variation And Water Resources Carrying Capacity Of Three Diversions Of Jing River

Faced with the hydrological effect which is affected by natural factors and human activities, Three Diversions of Jing River has been chosen as the study areas because of the seasonal and engineering shortage of water. Runoff variation characteristics have been studied and the contribution rate of each driver has been calculated. Moreover, the size and trend of water resources carrying capacity of Three Diversions have been probed in the context of the reduction in runoff. It has a great significance for probing the mechanism of runoff evolution in Jing River and Dongting Lake, finding effective way of rational development and utilization of water resources. The main contents and results are as follows(1) Hydrological series of Three Diversions in 1951~2012 have been counted, and spatial variations have been analyzed by using Linear regression method, Cumulant method and Mann-Kendall method. The following conclusions are obtained: The runoff spatial distribution of Three Diversions is nonuniform, and the runoff distribute nonuniformly in one year; The capacity varies largely between years and it has reduced with fluctuation in 1951~2012.The runoff annual variation has appeared the periodicity, and the mutation years are 1951,1972 and 1988.(2) Using accumulation slope change rate comparison method to separate the driving factors, and the following conclusions are obtained: Compared with Ta, in Tc(1967~1980) and Td(1981~2012), the change tendency of precipitation is in contrast with runoff, so the contribution of rainfall are negative; the main contribution factors are human activities(including the cut-off of Jing River and the construction and operation of Gezhouba Dam Hydropower Station) and the contribution of human activities are 101.02% 、 113.28%. In Tb(1951~1966) and Tc(2003~2012), the change tendency of precipitation is the same with runoff. The contribution of rainfall is more than 30% and because of the block of Tiaoxian and the construction of the Three Gorges, the contribution of human activities is more than 60%.(3) The largest economy, population size in 2010 and 2020 of Huarong, Anxiang and Nanxian and fuzzy comprehensive evaluation have been calculated. The following conclusions are obtained: The order of water resources carrying capacity is Anxiang> Nanxian> Huarong. The economy and population overload phenomenon of Huarong and Anxiang have been improved in 2020 and water resources carrying capacity of Nanxian is worse.It is indicated there are water shortages in Three Diversions. As long as we use it legitimately, the water carrying capacity will have some increase.