气候变化领域集成服务门户(CCPortal): Fluviomorphic trajectories for dryland ephemeral stream channels following extreme flash floods

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DOI	10.1002/esp.5847
	Fluviomorphic trajectories for dryland ephemeral stream channels following extreme flash floods
	Lotsari, Eliisa; House, P. Kyle; Alho, Petteri; Baker, Victor R.
发表日期	2024
ISSN	0197-9337
EISSN	1096-9837
英文摘要	Ephemeral alluvial streams pose globally significant flood hazards to human habitation in drylands, but sparse data for these regions limit understanding of the character and impacts of extreme flooding. In this study, we document decadal changes in dryland ephemeral channel patterns at two sites in the lower Colorado River Basin (southwestern United States) that were ravaged by extraordinary flash floods in the 1970s: Bronco Creek, Arizona (1971), and Eldorado Canyon, Nevada (1974). We refer to these two floods as 'fluviomorphic erasure events', because they produced blank slates for the channels that were gradually moulded by more frequent but much smaller flood events. We studied georectified aerial photos that span similar to 60 years at each site to show that both study sites recovered to their pre-flood condition after similar to 25 years. We employ channel network metrics: stream-link area (SLA), geometric braiding index and junction-node density. Each metric decreased during the short-duration extreme flood erasure events. Subsequently, a fluviomorphic trajectory at a decadal tempo returned the channels to pre-flood values. The SLA decreased at rates of 3.6%-4.1% per year in the decade following the floods. The extreme flood events decreased the pre-flood geometric braiding index at the two sites by 56%-68%, and it took 15-24 years for this index to recover to pre-flood values. In contrast, it took 30-35 years for the channels to recover to a uniform pre-flood channel form, as indicated by the spatial distribution of bars and junction nodes. Our results document baseline examples of ephemeral stream channel evolution trajectories, as future climatic change will likely accelerate increases in the magnitudes and frequencies of extreme floods and geomorphic erasure events.
英文关键词	bifurcation density; confluence density; drylands; ephemeral streams; flash flooding; fluviomorphic trajectory
语种	英语
WOS研究方向	Physical Geography ; Geology
WOS类目	Geography, Physical ; Geosciences, Multidisciplinary
WOS记录号	WOS:001214629200001
来源期刊	EARTH SURFACE PROCESSES AND LANDFORMS
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/302760
作者单位	Aalto University; University of Eastern Finland; University of Turku; United States Department of the Interior; United States Geological Survey; The National Land Survey of Finland; University of Arizona
推荐引用方式 GB/T 7714	Lotsari, Eliisa,House, P. Kyle,Alho, Petteri,et al. Fluviomorphic trajectories for dryland ephemeral stream channels following extreme flash floods[J],2024.
APA	Lotsari, Eliisa,House, P. Kyle,Alho, Petteri,&Baker, Victor R..(2024).Fluviomorphic trajectories for dryland ephemeral stream channels following extreme flash floods.EARTH SURFACE PROCESSES AND LANDFORMS.
MLA	Lotsari, Eliisa,et al."Fluviomorphic trajectories for dryland ephemeral stream channels following extreme flash floods".EARTH SURFACE PROCESSES AND LANDFORMS (2024).