气候变化领域集成服务门户(CCPortal): Accelerated river avulsion frequency on lowland deltas due to sea-level rise

CCPortal

DOI	10.1073/pnas.1912351117
	Accelerated river avulsion frequency on lowland deltas due to sea-level rise
	Chadwick A.J.; Lamb M.P.; Ganti V.
发表日期	2020
ISSN	0027-8424
起始页码	17584
结束页码	17590
卷号	117 期号:30
英文摘要	Sea-level rise, subsidence, and reduced fluvial sediment supply are causing river deltas to drown worldwide, affecting ecosystems and billions of people. Abrupt changes in river course, called avulsions, naturally nourish sinking land with sediment; however, they also create catastrophic flood hazards. Existing observations and models conflict on whether the occurrence of avulsions will change due to relative sea-level rise, hampering the ability to forecast delta response to global climate change. Here, we combined theory, numerical modeling, and field observations to develop a mechanistic framework to predict avulsion frequency on deltas with multiple self-formed lobes that scale with backwater hydrodynamics. Results show that avulsion frequency is controlled by the competition between relative sea-level rise and sediment supply that drives lobe progradation. We find that most large deltas are experiencing sufficiently low progradation rates such that relative sea-level rise enhances aggradation rates—accelerating avulsion frequency and associated hazards compared to preindustrial conditions. Some deltas may face even greater risk; if relative sea-level rise significantly outpaces sediment supply, then avulsion frequency is maximized, delta plains drown, and avulsion locations shift inland, posing new hazards to upstream communities. Results indicate that managed deltas can support more frequent engineered avulsions to recover sinking land; however, there is a threshold beyond which coastal land will be lost, and mitigation efforts should shift upstream. © 2020 National Academy of Sciences. All rights reserved.
英文关键词	River avulsion; River deltas; Sea-level rise
语种	英语
scopus关键词	Article; avulsion frequency; catchment area (hydrology); conceptual framework; controlled study; environmental change; hazard assessment; health hazard; human; hydrodynamics; landscape; lowland; mathematical computing; prediction; priority journal; risk evaluation and mitigation strategy; river; sea level rise; sediment; theory validation; threshold limit value
来源期刊	Proceedings of the National Academy of Sciences of the United States of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/160873
作者单位	Chadwick, A.J., Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, United States; Lamb, M.P., Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, United States; Ganti, V., Department of Geography, University of California, Santa Barbara, CA 93106, United States, Department of Earth Science, University of California, Santa Barbara, CA 93106, United States
推荐引用方式 GB/T 7714	Chadwick A.J.,Lamb M.P.,Ganti V.. Accelerated river avulsion frequency on lowland deltas due to sea-level rise[J],2020,117(30).
APA	Chadwick A.J.,Lamb M.P.,&Ganti V..(2020).Accelerated river avulsion frequency on lowland deltas due to sea-level rise.Proceedings of the National Academy of Sciences of the United States of America,117(30).
MLA	Chadwick A.J.,et al."Accelerated river avulsion frequency on lowland deltas due to sea-level rise".Proceedings of the National Academy of Sciences of the United States of America 117.30(2020).