Multiscale variability of sediment load and streamflow of the lower Yangtze River basin: Possible causes and implications
Multiscale variability of sediment load and streamflow of the lower Yangtze River basin: Possible causes and implications
复制标题
DOI：
10.1016/j.jhydrol.2009.01.030
复制
发表时间：
2009-04
影响因子：
6.4
通讯作者：
Qiang Zhang;Qiang Zhang;Chong-yu Xu;V. Singh;Tao Yang
中科院分区：
文献类型：
--
作者：
Qiang Zhang;Qiang Zhang;Chong-yu Xu;V. Singh;Tao Yang
应用扫描t检验、F检验和相干性分析技术，对长江下游大同站的月径流泥沙长序列进行了分析。结果表明：(1)水文序列一阶矩和二阶矩在不同时间尺度上的变化特征不同，反映了影响长江下游水文过程的不同驱动因素；(2)20世纪80年代中期以后，长江下游水文过程总体呈递减趋势。在泥沙负荷序列中分析了泥沙负荷的显著突变。然而，在径流的变化中可以观察到更复杂的变化规律。在较长的时间尺度上，输沙量的减少和径流量的增加导致了输沙量与径流之间的反相关系。输沙量与径流在较短时间尺度上的同相关系可能暗示了水文动力对输沙的重要影响；(3)人类活动，特别是水库的修建，对输沙量变化有很大的影响。长江支流和长江干流葛洲坝大坝的大量修建似乎是造成泥沙量突变的主要因素。三峡大坝的修建导致泥沙变化急剧减少且变异性不稳定，这对长江三角洲地区的生态环境保护和三角洲管理提出了新的挑战。
Long monthly streamflow and sediment load series observed at the Datong station located in the lower Yangtze River basin were analyzed using the scanning t-test, F-test and coherency analysis techniques. The results indicated that: (1) different changing properties of the first and the second moments of the hydrological series on different time scales were observed, reflecting different driving factors influencing the hydrological processes of the lower Yangtze River basin; (2) a generally decreasing trend can be identified after the mid-1980s. Significant abrupt changes in sediment load were analyzed in the sediment load series. However, more complicated changing patterns can be observed in the changes in streamflow. Generally decreasing sediment load and increasing streamflow gave rise to anti-phase relations between sediment load and the streamflow on longer time scales. In-phase relations between sediment load and streamflow on shorter time scales may imply a considerable influence of the hydrological dynamics on sediment transport; and (3) human activities, particularly the construction of water storage reservoirs, exerted a massive influence on sediment load variations. Construction of a large amount of water reservoirs on the tributaries of the Yangtze River and the Gezhouba Dam on the mainstem of the Yangtze River seem to be the main factors responsible for abrupt changes in the sediment load. Construction of the Three Gorges Dam causes a sharp decrease and unstable variability in sediment load variations, which may pose new challenges for the ecological environment conservation and the deltaic management of the Yangtze Delta region.