Runoff Analysis of the Middle Reaches of the Tarim River

According to hydrological data of many years,the runoff of the middle reaches of the Tarim River is analysed,including the characteristic,trend,reason and influence of runoff change which involves the annual runoff from 1957 to 2002 and the average monthly runoff from 1992 to 2002.The runoff of middle reaches of the Tarim River is unstable,uneven,and takes on a gradually reduced tendency.The reason is that a large amount of water is abused in the source rivers area and upper reaches area.The monthly runoff of the middle reaches of the Tarim River shows obvious the northwest river's feature.From July to September,the quantity of the water takes up 79.31% of whole year.Owing to agricultural irrigation,the runoff is descended from April to June.These features of runoff bring a lot of difficulties for the administration of water resources in the Tarim River.