气候变化领域集成服务门户(CCPortal): Thermal extremes in regulated river systems under climate change: An application to the southeastern U.S. rivers

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DOI	10.1088/1748-9326/ab8f5f
	Thermal extremes in regulated river systems under climate change: An application to the southeastern U.S. rivers
	Cheng Y.; Voisin N.; Yearsley J.R.; Nijssen B.
发表日期	2020
ISSN	17489318
卷号	15 期号:9
英文摘要	High river temperatures, or 'thermal extremes', can cause fish mortality and thermoelectric powerplant derating. Under climate change, projected higher air temperature and stronger surface energy fluxes will lead to increased water temperatures, exacerbating thermal extremes. However, cold hypolimnetic releases from thermally stratified reservoirs can depress tailwater temperatures and therefore alleviate thermal extremes. Thermal extremes are more harmful when they coincide with low flows, which we refer to as 'hydrologic hot-dry events'. To assess multi-sectoral impacts of climate change over large regions, we evaluate thermal events according to three impact attributes: duration (D), intensity (I), and severity (S). We apply an established model framework to simulate streamflow and stream temperature over the southeastern US regulated river system. We quantify climate change impacts (by the 2080s under RCP8.5) by comparing historical and future periods and quantify regulation impacts by comparing unregulated and regulated model setups. We find that climate change will exacerbate thermal extremes (all three metrics) in both unregulated and regulated model setups, albeit less in the regulated setup. Thermal mitigation from reservoir regulation will be stronger under climate change, decreasing the three metrics compared to the unregulated case. Even so, thermal extremes in the regulated setup will still be more severe under climate change, and only 12.2%, 19.7%, and 26.0% of D, I, and S can be mitigated by reservoirs. Despite stronger reservoir stratification, the number of regulated river segments that experience simultaneous high temperature and low flow events (hydrologic hot-dry events) will increase by 21.4% by the 2080s under RCP8.5. These events will have a median annual duration of 10.3 day/year, over 10 times the historical value. © 2020 The Author(s). Published by IOP Publishing Ltd.
英文关键词	climate change; reservoir regulation; reservoir thermal stratification; stream temperature; thermal extremes
语种	英语
scopus关键词	Climate models; Drought; Reservoirs (water); Rivers; Climate change impact; High temperature; Reservoir regulations; River temperature; Stream temperatures; Surface energy fluxes; Thermally stratified reservoir; Water temperatures; Climate change; air temperature; climate change; energy flux; extreme event; high temperature; mortality; power plant; river system; surface energy; water temperature; United States
来源期刊	Environmental Research Letters
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/153788
作者单位	Department of Civil and Environmental Engineering, University of Washington, Seattle, WA 98195, United States; Hydrology Group, Pacific Northwest National Laboratory, Seattle, WA 98109, United States
推荐引用方式 GB/T 7714	Cheng Y.,Voisin N.,Yearsley J.R.,et al. Thermal extremes in regulated river systems under climate change: An application to the southeastern U.S. rivers[J],2020,15(9).
APA	Cheng Y.,Voisin N.,Yearsley J.R.,&Nijssen B..(2020).Thermal extremes in regulated river systems under climate change: An application to the southeastern U.S. rivers.Environmental Research Letters,15(9).
MLA	Cheng Y.,et al."Thermal extremes in regulated river systems under climate change: An application to the southeastern U.S. rivers".Environmental Research Letters 15.9(2020).