Intercomparison of global reanalysis precipitation for flood risk modelling

Content Provider	Scilit
Author	McClean, Fergus Dawson, Richard Kilsby, Chris
Copyright Year	2021
Description	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 impact of using four reanalysis products (ERA-5, CFSR, MERRA-2 and JRA-55) on simulations of historic flood events in Northern England. These results are compared to a benchmark national gauge-based product (CEH-GEAR1hr). 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 the best across all basins. Global reanalysis products provide a useful resource for flood modelling where no other data is available, but they should be used with caution. Until a more systematic international strategy for the collection of rainfall data ensures more complete global coverage of validation data, multiple reanalysis products should be used concurrently to capture the range of uncertainties.
e-ISSN	18122116
DOI	10.5194/hess-2021-153
Journal	Hydrology and Earth System Sciences Discussions
Volume Number	2021
Language	English
Publisher	Copernicus GmbH
Publisher Date	2021-03-30
Access Restriction	Open
Subject Keyword	Water Science and Technology Global Reanalysis Flood Models
Content Type	Text
Resource Type	Article
Subject	Earth and Planetary Sciences Earth-Surface Processes