Sustained growth of river-mouth bars in the vulnerable Changjiang Delta
Sustained growth of river-mouth bars in the vulnerable Changjiang Delta
复制标题
脆弱的长江三角洲地区河口坝持续增长
DOI：
10.1016/j.jhydrol.2020.125450
复制
发表时间：
2020-11
影响因子：
6.4
通讯作者：
Hongmin Wang
中科院分区：
文献类型：
--
作者：
Xiaodong Zhang;Daidu Fan;Zuosheng Yang;Shumei Xu;Wanqing Chi;Hongmin Wang
基于1991 - 2018年的345幅卫星影像，研究了脆弱的长江三角洲两个新生河口拦门沙的高度、面积和形态变化及其影响因素。人类活动对河口沙坝发育的影响较小，因此，研究河口沙坝发育对揭示相对海平面上升和人类活动对河口沙坝发育的影响具有重要意义。长江三角洲河口拦门沙的形态变化受波浪、潮汐和径流的影响较大，但其高度和面积的增长取决于是否有充足的河流泥沙供给，相对海平面上升的影响相对较小。近30年来，尽管三峡大坝拦沙作用使上游泥沙大部分滞留，但位于活动河口的河口拦沙坝仍保持快速增长。我们认为，是大坝下游主槽冲刷的泥沙大量补充了排海泥沙，促成了河口拦门沙的快速增长。我们的发现启发了重新评估大坝建设对三角洲演变的影响时，大坝下游的泥沙储量大，径流量充足。在当前海平面快速上升和人类活动加剧的情况下，以河道泥沙补给为主的河口拦门沙快速增长，为保护脆弱的长江三角洲提供了宝贵的缓冲时间，也为世界其他主要三角洲的保护带来了希望和新的前景。
Based on 345 satellite images from 1991 to 2018, we examine the height, area and morphological changes of two large newborn river-mouth bars in the vulnerable Changjiang Delta as well as their influencing factors. The growth of inaccessible river-mouth bars is less affected by human estuarine activities, therefore, studying their growth shows particular promise in revealing the effects of relative sea level rise and human activities upstream of the river basin. We find the morphologic changes of the river-mouth bars in the Changjiang Delta are seriously affected by waves, tides and runoff, but their height and area growth depends on whether there is sufficient river sediment supply, and the impact of relative sea level rise is relatively small. The river-mouth bar located in the active distributary mouth has maintained rapid growth in the past three decades, although the Three Gorges Dam has trapped most of the upstream sediment. We believe it is the sediment scoured from the main channel downstream of the dam substantially supplements the sediment discharged to the sea, contributing to the rapid growth of the river-mouth bar. Our finding inspires a reassessment of the effects of dam construction on delta evolution when sediment reserves downstream of the dam are large and the runoff is ample. Under the current circumstances of rapid sea level rise and intensified human activities, the rapid growth of river-mouth bars mainly due to the sediment supply from the river channels allows precious buffer time to protect the vulnerable Changjiang Delta, and it also brings hope for and new perspectives on the protection of other major deltas in the world.
登录
查看更多内容
1998-2014年长江口最大自由岛近期形态动力演化：人为干扰的影响
影响因子：
2.3
作者：
Wei Wen;Mei Xuefei;Dai Zhijun;Tang Zhenghong
通讯作者：
Tang Zhenghong
由于沿海硬质结构和海岸线后退，黄河三角洲南部当前和未来的滩涂损失
影响因子：
4.4
作者：
Zhang Xiaodong;Lu Kai;Yin Ping;Zhu Longhai
通讯作者：
Zhu Longhai
1974—2010年长江三角洲岸线运动时空变化
影响因子：
3
作者：
Chu, Z.X.;Yang, X.;Feng, X.;Fan, D.;Li, Y.;Shen, X.;Miao, A.
通讯作者：
Miao, A.
中国长江口九段沙湿地的演变及通航工程的影响
影响因子：
3.9
作者：
Li Xing;Liu J Paul;Tian Bo
通讯作者：
Tian Bo
影响因子：
18.3
作者：
Syvitski, James P. M.;Kettner, Albert J.;Nicholls, Robert J.
通讯作者：
Nicholls, Robert J.