澜沧江河道冲淤变化特征及发展趋势

文章根据20多年来澜沧江河道断面形态、来水来沙的实测资料,分析了冲淤变化特征及其与来沙系数的相互关系。还根据澜沧江天然来沙量的变化趋势,梯级开发后可能发生的来沙量变化,探讨了澜沧江河道冲淤变化的可能发展趋势

Scouring and silting changes of Lancang River (Mekong River) and its development tendency

Lancang River is a mountain river Its river boundary is mainly composed of bedrocks and the alluvial material can only be found in a few slightly wide reaches Generally, suspended load is in unsaturated state, and bed load becomes important sediment movement Owing to lack of real bed load data, it is very difficulty to study scouring and silting changes of the Lancang River In this paper, we use the survey data of the individual sections and compare their areas at different durations, then analyze their correlation to the coefficient of incoming sediment The results show that: (1) change amplitude of scouring and silting is not great, the accumulated change amplitude of Yunjinhong section during more than 20 years is only 20 2m 2 and of Jiuzhou section is only 2 05m 2 (2) there is a kind of, but not very good correlation of change amplitude of scouring and silting to coefficient of incoming sediment When the coefficient of the incoming sediment increases, silting happens, conversely, scouring happens Based on these results mentioned, the future development tendency of scouring and silting changes is also studied Two possibly happened environmental changes are considered in the study, increase of the incoming sediment caused by increasing human activities and a series of water conservancy projects will be built Because changing direction of these two is inverse each other, the scouring and silting change of the Lanchang River is approximately the same to the present situation .