Flood Size Increases Nonlinearly Across the Western United States in Response to Lower Snow‐Precipitation Ratios

Water Resources Research, Journal Year: 2019, Volume and Issue: 56(1)

Published: Dec. 21, 2019

Abstract Many mountainous and high‐latitude regions have experienced more precipitation as rain rather than snow due to warmer winter temperatures. Further decreases in the annual fraction are projected under continued global warming, with potential impacts on flood risk. Here, we quantify size of streamflow peaks response both seasonal event‐specific rain‐fraction using stream gage observations from watersheds across western United States. Across study watersheds, largest rainfall‐driven >2.5 times snowmelt‐driven peaks. Using a panel regression analysis individual snowmelt events, show that empirical grows approximately exponentially liquid input increases, rain‐dominated runoff leading proportionately larger increases or mixed rain‐and‐snow runoff. We find changes percentage is wettest where wet antecedent conditions important for increasing efficiency. Similarly, effect Northwest West compared Northern Rockies Southwest regions. Overall, higher falls rain, “rain‐on‐snow”‐driven floods offset floods.

Language: Английский

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Geomorphic and Sedimentary Effects of Modern Climate Change: Current and Anticipated Future Conditions in the Western United States

Reviews of Geophysics, Journal Year: 2020, Volume and Issue: 58(4)

Published: Oct. 24, 2020

Abstract Hydroclimatic changes associated with global warming over the past 50 years have been documented widely, but physical landscape responses are poorly understood thus far. Detecting sedimentary and geomorphic signals of modern climate change presents challenges owing to short record lengths, difficulty resolving in stochastic natural systems, influences land use tectonic activity, long‐lasting effects individual extreme events, variable connectivity sediment‐routing systems. We review existing literature investigate nature extent change, focusing on western United States, a region generally high relief sediment yield likely be sensitive climatic forcing. Based fundamental theory empirical evidence from other regions, we anticipate climate‐driven slope stability, watershed yields, fluvial morphology, aeolian mobilization States. find for recent stability increased dune dust whereas yields morphology linked more commonly nonclimatic drivers will require better understanding how response scales disturbance, lag times hysteresis operate within distinguish relative influence feedbacks superimposed disturbances. The ability constrain rapidly progressing has widespread implications human health safety, infrastructure, water security, economics, ecosystem resilience.

Language: Английский

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Understanding the relationship between rainfall and flood probabilities through combined intensity-duration-frequency analysis

Journal of Hydrology, Journal Year: 2021, Volume and Issue: 602, P. 126759 - 126759

Published: Aug. 2, 2021

The aim of this paper is to explore how rainfall mechanisms and catchment characteristics shape the relationship between flood probabilities. We propose a new approach comparing intensity-duration-frequency statistics maximum annual with those streamflow in order infer behavior for runoff extremes. calibrate parsimonious scaling models data from 314 rain gauges 428 stream Austria, analyze spatial patterns resulting distributions model parameters. Results indicate that extremes tend be more variable dry lowland catchments dominated by convective than mountainous where higher are mainly orographic. Flood frequency curves always steeper corresponding exception glaciated catchments. Based on proposed combined we elasticities as percent change discharge 1% extreme through quantiles. In wet catchments, unity, i.e. have similar steepness, due persistently high soil moisture levels. much higher, implying floods rainfall, which interpreted terms skewed event coefficients. While regional differences can attributed both dominating characteristics, our results suggest controls. With increasing return period, towards consistent various generation concepts. Our findings may useful process-based extrapolation climate impact studies, further studies encouraged tail elasticities.

Language: Английский

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A data-driven analysis of flash flood hazard, fatalities, and damages over the CONUS during 1996–2017

Journal of Hydrology, Journal Year: 2019, Volume and Issue: 578, P. 124106 - 124106

Published: Sept. 4, 2019

Language: Английский

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A benefit–cost analysis of floodplain land acquisition for US flood damage reduction

Nature Sustainability, Journal Year: 2019, Volume and Issue: 3(1), P. 56 - 62

Published: Dec. 9, 2019

Language: Английский

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