云南浑水沟泥石流与大盈江河床演变

通过对浑水沟泥石流治理前后,泥石流输沙量变化与大盈江南底河段河床演变关系的研究,指出泥石流沟对主河河床演变影响的主要原因是,支沟泥石流输入主河泥沙数量的急剧变化改变了主河的来沙条件,导致主河河床的剧烈演变。当支沟泥石流输入主河的泥沙量大于主河输沙量时,主河河床将上涨,在宽谷或山间盆地可形成与平原河流相似的游荡性河流;当支沟泥石流输入主河的泥沙量小于主河的输沙量时,主河河床将下切,并逐渐恢复山区性河流的特征。

Debris flow in Hunshui Gully and fluvial processes of Dayingjiang River in Yunnan Province

The paper studied the relationship between the change of debris flow in Hunshui Gully and the fluvial processes of the Nandi reach of Dayingjiang River before and after the management of Hunshui Gully. The main reason affecting the fluvial processes of the main stream is the debris flow gullies. The debris load from gullies changes the flow and sediment condition of the main stream. This causes an obvious change of the main stream. The channel bed of the main stream will grow up if the debris amount from branch gullies is bigger than that the main stream could carry and the meandering stream may be formed in wide valley or basin. The main channel bed will scour if sediment amount from tributary debris is less than that the main stream can carry and the river evolution exhibits the characteristic of mountainous rivers.