Preprints
https://doi.org/10.5194/hess-2021-153
https://doi.org/10.5194/hess-2021-153

  30 Mar 2021

30 Mar 2021

Review status: this preprint is currently under review for the journal HESS.

Intercomparison of global reanalysis precipitation for flood risk modelling

Fergus McClean1, Richard Dawson1, and Chris Kilsby1,2 Fergus McClean et al.
  • 1School of Engineering, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK
  • 2Willis Research Network, 51 Lime St., London, EC3M 7DQ, UK

Abstract. 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.

Fergus McClean et al.

Status: open (until 25 May 2021)

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
  • RC1: 'Comment on hess-2021-153', Anonymous Referee #1, 30 Apr 2021 reply

Fergus McClean et al.

Fergus McClean et al.

Viewed

Total article views: 309 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
231 70 8 309 2 1
  • HTML: 231
  • PDF: 70
  • XML: 8
  • Total: 309
  • BibTeX: 2
  • EndNote: 1
Views and downloads (calculated since 30 Mar 2021)
Cumulative views and downloads (calculated since 30 Mar 2021)

Viewed (geographical distribution)

Total article views: 283 (including HTML, PDF, and XML) Thereof 283 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 
Latest update: 09 May 2021
Download
Short summary
Reanalysis datasets are increasingly used to drive flood models, especially for continental and global analysis. We investigate the impact of using four reanalysis products on simulations of historic flood events. All reanalysis products underestimated the number of buildings inundated, CFSR by the least (14 %) and JRA-55 the most (40 %). These findings show that while global reanalyses provide a useful resource for flood modelling where no other data is available, they must be used with caution.