Sediment budget and morphological change in the Red River Delta under increasing human interferences
Sediment budget and morphological change in the Red River Delta under increasing human interferences
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人类干扰加剧下红河三角洲泥沙收支与形态变化
DOI：
10.1016/j.margeo.2020.106379
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发表时间：
2021
期刊：
影响因子：
2.9
通讯作者：
Tran Dinh Lan
中科院分区：
文献类型：
--
作者：
Nguyen Dac Ve;Daidu Fan;Bui Van Vuong;Tran Dinh Lan
人类活动对红河三角洲泥沙扩散系统的影响越来越大，但从整体角度研究红河三角洲的形态动力学变化和泥沙收支却很少。本文通过对1960 - 2010年河川水沙流量的时间序列分析，追踪人类对泥沙运移过程的干扰，并对1930 - 2008年河川河川历史图进行数字化处理，重建河川河川河川地貌时空变化的数字高程模型，计算河川河川河川河川的沉积和侵蚀通量。结果表明：红河泥沙减少61.3%主要是由于大江下游和平大坝的建设，近期森林砍伐和其他土地利用变化显著增加了大江和罗江的泥沙负荷。RRD的潮间带和潮下形态变化在自然和人为驱动下具有高度的地点特异性。潮间带快速淤积主要发生在分流口附近，主要是由于填海造地工程带来的大量泥沙供应和人为淤积，但在分流口移动后或风暴事件暂时发生严重的海岸侵蚀。水下RRD的一般特征是侵蚀和增生的等高线平行带，由与季风相关的强岸流决定。在以潮汐为主的北部水下RRD，由于近20年来泥沙输入减少，净侵蚀在近期转变为轻微侵蚀，而在以波浪和海岸流为主的南部水下RRD，由于分流出口转移和长期形态动力学调整，净侵蚀在近期进入轻微侵蚀阶段。研究区平均接收悬浮沉积物41.1 Mt./yr (Mt = 106t)，其中潮间带和北部水下RRD分别为14.2 Mt./yr和28.6 Mt./yr。然而，南部水下RRD的侵蚀可为该系统贡献42.9 mt /年的沉积物。因此，有41.2 mt /yr的悬浮物从研究的RRD区域逃逸，并沿越南陆架内部进一步向南运输，形成远端泥质斜地形。这种泥沙收支估算虽然具有很大的不确定性，但为大三角洲系统的多年代际泥沙扩散和海岸管理提供了重要信息。
The Red River sediment dispersal system has been increasingly altered by human activities, but the resultant morphodynamic change and sediment budget in the Red River Delta (RRD) has been little studied in a holistic perspective. In this study, time-series analysis of river water and sediment discharges from 1960 to 2010 was carried out to trace human interferences on sediment routing processes, and historical charts from 1930 to 2008 were digitized to reconstruct the Digital Elevation Models for investigating spatiotemporal variations in the RRD morphology and calculating their depositional and erosional fluxes. The results show that sediment reduction by 61.3% in the Red River is mainly induced by constructing the Hoa Binh Dam at the lower reach of the Da river, and deforestation and other land-use change have recently increased significantly the sediment loads in the Thao and Lo rivers. Intertidal and subtidal morphological changes in the RRD are highly site-specific in response to natural and anthropogenic drivers. Rapid intertidal accretion majorly occurs near the distributary mouths because of abundant sediment supply and artificially promoted siltation by land reclamation projects, but severe coastal erosion may occur secularly after the distributary outlet shifting or temporarily by storm events. The subaqueous RRD is generally featured by the contour-parallel zonation of erosion and accretion determined by strong longshore currents associated with monsoon winds. Net accretion was observed in the tide-dominated northern subaqueous RRD and has recently changed into a slight erosion due to reduced sediment input in the last two decades, while net erosion was monitored in the southern subaqueous RRD predominated by wave and longshore currents and has recently entered into a slight accretion phase in response to the distributary outlet shifting and secular morphodynamic adjustment. The study RRD region received on average 41.1 Mt./yr (Mt = 106t) of suspended sediments, and 14.2 Mt./yr and 28.6 Mt./yr were estimated to accumulate on the intertidal flats and in the northern subaqueous RRD, respectively. However, erosion in the southern subaqueous RRD could contribute 42.9 Mt./yr of sediment to the system. Therefore, 41.2 Mt./yr of suspended sediment was indicated to escape from the study RRD region and transport further southward by longshore current to form the distal muddy clinoform along the inner Vietnam shelf. This sediment budget estimation should bear a significant uncertainty, but provides important information for multi-decadal sediment dispersal in a mega-delta system and coastal management.
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影响因子：
1.6
作者：
Bui Vuong Van;Fan Daidu;Nguyen Dac Ve;Tran Dinh Lan;Tran Duc Thanh;Hoang Van Long;Nguyen Thi Hong Hanh
通讯作者：
Nguyen Thi Hong Hanh
影响因子：
3.8
作者：
E. Mueller;J. Schmidt;D. Topping;P. Shafroth;J. E. Rodríguez‐Burgueño;J. Ramírez-Hernández;P. Grams-P.-G
通讯作者：
E. Mueller;J. Schmidt;D. Topping;P. Shafroth;J. E. Rodríguez‐Burgueño;J. Ramírez-Hernández;P. Grams-P.-G
影响因子：
3
作者：
G. D. Bergh;W. Boer;M. Schaapveld;D. M. Duc;T. V. Weering
通讯作者：
G. D. Bergh;W. Boer;M. Schaapveld;D. M. Duc;T. V. Weering
影响因子：
6.3
作者：
V. D. Vinh;S. Ouillon;Tran Duc Thanh;L. Chu
通讯作者：
V. D. Vinh;S. Ouillon;Tran Duc Thanh;L. Chu
影响因子：
3
作者：
Thi-Minh-Ngoc Luu;J. Garnier;G. Billen;D. Orange;J. Némery;T. Le;Hong Thai Tran;L. Le
通讯作者：
Thi-Minh-Ngoc Luu;J. Garnier;G. Billen;D. Orange;J. Némery;T. Le;Hong Thai Tran;L. Le