Intercomparison of global reanalysis precipitation for flood risk modelling

<p>Reanalysis datasets are increasingly used to drive flood models, especially for continental and global analysis and in areas of data scarcity. However, the consequence of this for risk estimation has not been fully explored. We investigate the implications of four reanalysis products (ERA-5...

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Main Authors: F. McClean, R. Dawson, C. Kilsby
Format: Article
Language:English
Published: Copernicus Publications 2023-01-01
Series:Hydrology and Earth System Sciences
Online Access:https://hess.copernicus.org/articles/27/331/2023/hess-27-331-2023.pdf
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author F. McClean
R. Dawson
C. Kilsby
C. Kilsby
author_facet F. McClean
R. Dawson
C. Kilsby
C. Kilsby
author_sort F. McClean
collection DOAJ
description <p>Reanalysis datasets are increasingly used to drive flood models, especially for continental and global analysis and in areas of data scarcity. However, the consequence of this for risk estimation has not been fully explored. We investigate the implications of four reanalysis products (ERA-5, CFSR, MERRA-2 and JRA-55) on simulations of historic flood events in five basins in England. These results are compared to a benchmark national gauge-based product (CEH-GEAR1hr). The benchmark demonstrated better accuracy than reanalysis products when compared with observations of water depth and flood extent. All reanalysis products predicted fewer buildings would be inundated by the events than the national dataset. JRA-55 was the worst by a significant margin, underestimating by 40 % compared with 14 %–18 % for the other reanalysis products. CFSR estimated building inundation the most accurately, while ERA-5 demonstrated the lowest error in terms of river stage (29.4 %) and floodplain depth (28.6 %). Accuracy varied geographically, and no product performed best across all basins. Global reanalysis products provide a useful resource for flood modelling where no other data are available, but they should be used with caution due to the underestimation of impacts shown here. Until a more systematic international strategy for the collection of rainfall and flood impact data ensures more complete global coverage for validation, multiple reanalysis products should be used concurrently to capture the range of uncertainties.</p>
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spelling doaj.art-dd4b44f48e4846ebaeb95dcec7f27bec2023-01-18T11:03:07ZengCopernicus PublicationsHydrology and Earth System Sciences1027-56061607-79382023-01-012733134710.5194/hess-27-331-2023Intercomparison of global reanalysis precipitation for flood risk modellingF. McClean0R. Dawson1C. Kilsby2C. Kilsby3School of Engineering, Newcastle University, Newcastle upon Tyne, NE1 7RU, UKSchool of Engineering, Newcastle University, Newcastle upon Tyne, NE1 7RU, UKSchool of Engineering, Newcastle University, Newcastle upon Tyne, NE1 7RU, UKWillis Research Network, 51 Lime St., London, EC3M 7DQ, UK<p>Reanalysis datasets are increasingly used to drive flood models, especially for continental and global analysis and in areas of data scarcity. However, the consequence of this for risk estimation has not been fully explored. We investigate the implications of four reanalysis products (ERA-5, CFSR, MERRA-2 and JRA-55) on simulations of historic flood events in five basins in England. These results are compared to a benchmark national gauge-based product (CEH-GEAR1hr). The benchmark demonstrated better accuracy than reanalysis products when compared with observations of water depth and flood extent. All reanalysis products predicted fewer buildings would be inundated by the events than the national dataset. JRA-55 was the worst by a significant margin, underestimating by 40 % compared with 14 %–18 % for the other reanalysis products. CFSR estimated building inundation the most accurately, while ERA-5 demonstrated the lowest error in terms of river stage (29.4 %) and floodplain depth (28.6 %). Accuracy varied geographically, and no product performed best across all basins. Global reanalysis products provide a useful resource for flood modelling where no other data are available, but they should be used with caution due to the underestimation of impacts shown here. Until a more systematic international strategy for the collection of rainfall and flood impact data ensures more complete global coverage for validation, multiple reanalysis products should be used concurrently to capture the range of uncertainties.</p>https://hess.copernicus.org/articles/27/331/2023/hess-27-331-2023.pdf
spellingShingle F. McClean
R. Dawson
C. Kilsby
C. Kilsby
Intercomparison of global reanalysis precipitation for flood risk modelling
Hydrology and Earth System Sciences
title Intercomparison of global reanalysis precipitation for flood risk modelling
title_full Intercomparison of global reanalysis precipitation for flood risk modelling
title_fullStr Intercomparison of global reanalysis precipitation for flood risk modelling
title_full_unstemmed Intercomparison of global reanalysis precipitation for flood risk modelling
title_short Intercomparison of global reanalysis precipitation for flood risk modelling
title_sort intercomparison of global reanalysis precipitation for flood risk modelling
url https://hess.copernicus.org/articles/27/331/2023/hess-27-331-2023.pdf
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AT ckilsby intercomparisonofglobalreanalysisprecipitationforfloodriskmodelling