Analysis on hydrologic characteristics of Poyang lake

Abstract

Poyang lake is the largest freshwater lake in China at present.Using large amount of measured data,recent precipitation,runoff,flood,sediment transport characteristics as well as their variation within a year and over years and regional distribution law are analysed.The encounter probability of Poyang lake flood with Yangtze flood and the reservoir action of Poyang lake to the Yangtze flood are analysed and computed.According to water balance principle,the flood peak regulation-storage volume of Poyang lake and the Yangtze for maximum 60 d flood volume in 9 typical high or low flood years of 1968,1969,1973,1980,1983,1996,1998,etc.,are computed.The regulation-storage volumes of the river and the lake in these 9 years are 5 6～16 5 billion m\+3,with an average volume of 11 5 billion m\+3,in which,the average regulation-storage volume of Poyang lake is 9 5 billion m\+3,82 6% of the total regulation-storage volume,Poyang lake plays an important role in the reservoir action for the floods of 5 main tributaries in its basin and the floods of the Yangtze down to Bali.Without the regulation and storage,the flood of the middle-lower Yangtze,especially in the areas near the Hukou,will be more frequent and serious.