关键词: 冲淤变化, 来水来沙, 澜沧江

Abstract:

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 20.2m²and of Jiuzhou section is only 2.05m²(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 .

Key words: Lancang River, scouring and silting changes, incoming water and sediments