A model of water and sediment balance as determinants of relative sea level rise in contemporary and future deltas
A model of water and sediment balance as determinants of relative sea level rise in contemporary and future deltas
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DOI：
10.1016/j.geomorph.2017.09.040
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发表时间：
2018-03-15
期刊：
影响因子：
3.9
通讯作者：
Syvitski, James P. M.
中科院分区：
文献类型：
--
作者：
Tessler, Zachary D.;Voeroesmarty, Charles J.;Syvitski, James P. M.
现代三角洲依赖于人类介导的淡水和沉积物通量。这些通量的变化会影响三角洲的生态物理功能，并影响这些景观对人类和自然系统的长期可持续性。在这里，我们提出的长期平均沉积物平衡和相对海平面上升的当代估计在46个全球三角洲。我们模拟的情景，当代和未来的水资源管理计划和水电基础设施在上游流域，以探讨如何改变泥沙通量影响相对海平面上升三角洲系统。模型结果表明，当代沉积物通量，地面沉降的人为驱动因素和海平面上升导致三角洲相对海平面上升率平均为6.8毫米/年。评估计划中和在建的水坝对相对海平面上升率的影响表明，随着上游新的建设，三角洲的海平面上升率将增加1毫米/年。如果目前计划的所有水坝都建成，多瑙河的沉积物通量估计将减少60%，恒河-雅鲁藏布江-梅克纳江的沉积物通量将减少21%。河流渠化和管理的增加导致三角洲的泥沙滞留减少，影响更大，平均每年增加近2毫米的相对海平面上升。三角洲的长期可持续性需要更全面地了解地球物理和人为变化如何影响三角洲地貌。即使在全球气候导致海平面上升的背景下，地方和区域可持续三角洲管理战略，如果侧重于地方和区域变化驱动因素，特别是地下水和碳氢化合物开采以及上游水坝建设，也可能产生很大影响。(C)2017作者由爱思唯尔公司出版
Modern deltas are dependent on human-mediated freshwater and sediment fluxes. Changes to these fluxes impact delta biogeophysical functioning and affect the long-term sustainability of these landscapes for human and for natural systems. Here we present contemporary estimates of long-term mean sediment balance and relative sea level rise across 46 global deltas. We model scenarios of contemporary and future water resource management schemes and hydropower infrastructure in upstream river basins to explore how changing sediment fluxes impact relative sea level rise in delta systems. Model results show that contemporary sediment fluxes, anthropogenic drivers of land subsidence, and sea level rise result in delta relative sea level rise rates that average 6.8 mm/y. Assessment of impacts of planned and under-construction dams on relative sea level rise rates suggests increases on the order of 1 mm/y in deltas with new upstream construction. Sediment fluxes are estimated to decrease by up to 60% in the Danube and 21% in the Ganges-Brahmaputra-Meghna if all currently planned dams are constructed. Reduced sediment retention on deltas caused by increased river channelization and management has a larger impact, increasing relative sea level rise on average by nearly 2 mm/y. Longterm delta sustainability requires a more complete understanding of how geophysical and anthropogenic change impact delta geomorphology. Local and regional strategies for sustainable delta management that focus on local and regional drivers of change, especially groundwater and hydrocarbon extraction and upstream dam construction, can be highly impactful even in the context of global climate-induced sea level rise. (C) 2017 The Authors. Published by Elsevier B.V.