Response of downstream sediment to water resource development in mainstream of the Lancang River

• Published in: Chinese science bulletin 2006-11, Vol.51 (B11), p.119-126
• Main Authors: Fu, K, He, D, Li, S
• Format: Article
• Language: English
• Subjects: Freshwater; 回归分析; 水文学; 沉积物浓度变异; 澜沧江-湄公河
• ISSN: 1001-6538; 1861-9541
• DOI: 10.1007/s11434-006-8119-x

The impact of hydropower cascades of the Lancang River on downstream sedimentation has become one of the key problems in the research of the transboundary water resource development and its possible environmental effects. In this paper, the newest sediment data series spanning 17 years （1987-2003） at Yunjinghong hydrometric station and Chiang Saen hydrometric station, in northern Thailand, are analyzed to reveal these effects. Monthly mean sediment concentration data of the two stations are compared in-phase and yearly series are analyzed by the method of correlation and regression analysis and causality test. The analysis result shows that, though both of them are located at lower reaches of Manwan and Dachaoshan hydropower stations which are already constructed and in use, the sediment responses of the two stations are different under the regulation of the hydropower stations Annual series at Yunjinghong station are positively correlated but do not match well with those at Chiang Saen station. In addition, the results of Granger causality test on the time series also suggest that the series of maximum monthly mean sediment concentration of the Yunjinghong station each year may give cause for the ones of Chiang Saen station, while the series of minimum monthly mean sediment concentration each year and annual mean sediment concentration of Yunjinghong do not evidently give cause for the ones of the other station. Undoubtedly, this discovery will provide new evidences to assess the impacts of cascades construction in mainstream of the Lancang River on the variation of downstream sediment and its transboundary effects.