鄱阳湖水文特性分析

鄱阳湖是我国目前最大的淡水湖泊。应用大量实测资料，分析了鄱阳湖流域近期降水、径流、洪水、输沙等水文特性，探讨了年内年际变化及地区分布规律，并分析计算了鄱阳湖与长江洪水遭遇机率和鄱阳湖对长江洪水的调蓄作用。根据水量平衡原理，计算出鄱阳湖及长江对1968、1969、1973、1980、1983、1996、1998年等9个典型大水年最大60d洪量对应的一次洪峰调蓄，江湖调蓄量为56～165亿m^3，平均115亿m^3，其中鄱阳湖调蓄平均为95亿m^3，占总调蓄量的82.6%。鄱阳湖对五河洪水调蓄作用是很大的，对长江至八里洪水的调蓄作用也较大，如果没有其调蓄，长江中下游特别是湖口附近区域的洪水将更为频敏和严重。

Analysis on hydrologic characteristics of Poyang lake

Poyang lake is the largest freshwater lake in China atpresent.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 m3,with an average volume of 11.5 billion m3,in which,the average regulation-storage volume of Poyang lake is 9.5 billion m3,82.6% 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.