长江流域水沙输移特性

Characteristics of Discharge and SedimentTransportation in Yangtze River

该文通过对长江上、中、下游 (以宜昌站、汉口站、大通站为代表 )径流量和输沙量自186 5～ 1985年记录的统计以及两者的相关分析 ,阐明了长江水沙输移的时空分布特征 :径流量从上游向下游明显增加 ;输沙量洪季自上游向中游递减 ,下游较中游稍有增加但仍低于上游 ,枯季从上游向下游增加。这种分布特征受河道比降、河流类型、水流流速、沉积物粒径范围。

A multi yearly (1865 1985) hydrological records were collected from the upper, mid and lower Yangtze drainage basin, respectively, to examine the temporal and spatial distribution of the discharge and sediment load. The result shows that the Yangtze discharge obviously increases from the upper drainage basin downstream. Sediment load along the Yangtze is reversal to what was observed from the discharge. Dramatic reduction in sediment load occurs in the mid Yangtze to account for the changes of river variables such as decreased slope and evolved plain river pattern of the mid Yangtze from the upper reach. Sediment load in the lower Yangtze, even still significantly less than that of the upper Yangtze, becomes slightly increased from the mid Yangtze.