Uncertainty in the extreme flood magnitude estimates of large-scale flood hazard models

14Citations
Citations of this article
46Readers
Mendeley users who have this article in their library.

This article is free to access.

Abstract

The growing worldwide impact of flood events has motivated the development and application of global flood hazard models (GFHMs). These models have become useful tools for flood risk assessment and management, especially in regions where little local hazard information is available. One of the key uncertainties associated with GFHMs is the estimation of extreme flood magnitudes to generate flood hazard maps. In this study, the 1-in-100 year flood (Q100) magnitude was estimated using flow outputs from four global hydrological models (GHMs) and two global flood frequency analysis datasets for 1350 gauges across the conterminous US. The annual maximum flows of the observed and modelled timeseries of streamflow were bootstrapped to evaluate the sensitivity of the underlying data to extrapolation. Results show that there are clear spatial patterns of bias associated with each method. GHMs show a general tendency to overpredict Western US gauges and underpredict Eastern US gauges. The GloFAS and HYPE models underpredict Q100 by more than 25% in 68% and 52% of gauges, respectively. The PCR-GLOBWB and CaMa-Flood models overestimate Q100 by more than 25% at 60% and 65% of gauges in West and Central US, respectively. The global frequency analysis datasets have spatial variabilities that differ from the GHMs. We found that river basin area and topographic elevation explain some of the spatial variability in predictive performance found in this study. However, there is no single model or method that performs best everywhere, and therefore we recommend a weighted ensemble of predictions of extreme flood magnitudes should be used for large-scale flood hazard assessment.

Register to see more suggestions

Mendeley helps you to discover research relevant for your work.

Already have an account?

Cite

CITATION STYLE

APA

Devitt, L., Neal, J., Wagener, T., & Coxon, G. (2021). Uncertainty in the extreme flood magnitude estimates of large-scale flood hazard models. Environmental Research Letters, 16(6). https://doi.org/10.1088/1748-9326/abfac4

Readers' Seniority

Tooltip

PhD / Post grad / Masters / Doc 9

41%

Researcher 9

41%

Lecturer / Post doc 4

18%

Readers' Discipline

Tooltip

Earth and Planetary Sciences 9

50%

Engineering 7

39%

Philosophy 1

6%

Computer Science 1

6%

Article Metrics

Tooltip
Mentions
Blog Mentions: 1

Save time finding and organizing research with Mendeley

Sign up for free