Analysis Of Runoff Characteristics In Water Transfer Region Of The Western Route Of The South-to-North Water Transfer Scheme

The western route of the South-to-North water transfer scheme is the important component of the basic framework for South-to-North water transfer scheme master plan , the major project of inter-basin water transfering from the Yangtze River upstream to the Yellow River upstream, one of the effective ways to complement to the water resources shortage and keep long healthy life of Yellow River ,and also a significant strategic to against the drought and water shortage of domestic northwestern Region. This thesis make a deep research on runoff characteristics and wetness-dryness of the western route of the South-to-North water transfer scheme. Mainly concluded as below:(1)Analyzing with the mathematical statistic method,Mann-Kendall rank correlation test,sliding average method and accumulated difference method. We find the rich water months is mainly concentrated from May to October and the variation is not obvious. The annual change trend of the runoff in Aan, Renda dam site is not obvious, in Shangduke dam site increase gently,while in Yaertang and Keke dam site is slowly droping. In addition, the introduction power spectrum method has also been carried on to analyze the runoff cycle.(2)Taking the run theory method to analyze the annual richness and the dryness of each runoff characteristics,we find that the probability of annal abundance and dryness is great and the posibility is droping with the increasing of the time. Adopting the method of Markov Process to analyze the the transfer probability on abundance and dryness, we find the self-transfer probability in abundand and dryness period is greater than it in common water period. In the process of mutual- transferring , no matter what the state the runoff is, the transfer probability of the abundand and dryness is much bigger than the common water .(3)A respective analysis of wetness-dryness encountering has been done to the river basin and the runoff between either two river basins, which belong to the Yalong river district and Dadu river district. It's not necessary to carry out the compensating operation when there's the phenomenon like ample flow, common water occurring. As all hubs can work normally also. The frequency of ample flow and common water are of 26.32% and 2.63% . The compensating operation can be taken for the rivers to ensure the reliability of the water transferring when the wetness-dryness asynchronous of runoff comes up. It's adverse for water transferring when the runoffs are in dryness alike. If in this case, the reliability of water transferring will be threatened. The frequency of the dryness is 26.32%. It's clear that there's still a chance for the most adverse situation happening during the water transferring. On the whole, the runoffs in area of water supplying are in good position for water transferring, the frequency is 73.68%.