The role of spatial dependence for large-scale flood risk estimation
<p>Flood risk assessments are typically based on scenarios which assume homogeneous return periods of flood peaks throughout the catchment. This assumption is unrealistic for real flood events and may bias risk estimates for specific return periods. We investigate how three assumptions about t...
| Main Authors: | , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2020-04-01
|
| Series: | Natural Hazards and Earth System Sciences |
| Online Access: | https://www.nat-hazards-earth-syst-sci.net/20/967/2020/nhess-20-967-2020.pdf |
| _version_ | 1819230131589218304 |
|---|---|
| author | A. D. Metin A. D. Metin N. V. Dung K. Schröter S. Vorogushyn B. Guse H. Kreibich B. Merz B. Merz |
| author_facet | A. D. Metin A. D. Metin N. V. Dung K. Schröter S. Vorogushyn B. Guse H. Kreibich B. Merz B. Merz |
| author_sort | A. D. Metin |
| collection | DOAJ |
| description | <p>Flood risk assessments are typically based on scenarios which
assume homogeneous return periods of flood peaks throughout the catchment.
This assumption is unrealistic for real flood events and may bias risk
estimates for specific return periods. We investigate how three assumptions
about the spatial dependence affect risk estimates: (i) spatially
homogeneous scenarios (complete dependence), (ii) spatially heterogeneous
scenarios (modelled dependence) and (iii) spatially heterogeneous but
uncorrelated scenarios (complete independence). To this end, the model chain
RFM (regional flood model) is applied to the Elbe catchment in Germany,
accounting for the spatio-temporal dynamics of all flood generation processes,
from the rainfall through catchment and river system processes to damage
mechanisms. Different assumptions about the spatial dependence do not
influence the expected annual damage (EAD); however, they bias the risk
curve, i.e. the cumulative distribution function of damage. The widespread
assumption of complete dependence strongly overestimates flood damage of the
order of 100 % for return periods larger than approximately 200 years. On
the other hand, for small and medium floods with return periods smaller than
approximately 50 years, damage is underestimated. The overestimation
aggravates when risk is estimated for larger areas. This study demonstrates
the importance of representing the spatial dependence of flood peaks and
damage for risk assessments.</p> |
| first_indexed | 2024-12-23T11:24:12Z |
| format | Article |
| id | doaj.art-f5721de321b84d5a93764411c0a70d26 |
| institution | Directory Open Access Journal |
| issn | 1561-8633 1684-9981 |
| language | English |
| last_indexed | 2024-12-23T11:24:12Z |
| publishDate | 2020-04-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Natural Hazards and Earth System Sciences |
| spelling | doaj.art-f5721de321b84d5a93764411c0a70d262022-12-21T17:49:00ZengCopernicus PublicationsNatural Hazards and Earth System Sciences1561-86331684-99812020-04-012096797910.5194/nhess-20-967-2020The role of spatial dependence for large-scale flood risk estimationA. D. Metin0A. D. Metin1N. V. Dung2K. Schröter3S. Vorogushyn4B. Guse5H. Kreibich6B. Merz7B. Merz8Hydrology Section, GFZ German Research Centre for Geosciences, 14473 Potsdam, GermanyInstitute of Environmental Science and Geography, University of Potsdam, 14476 Potsdam, GermanyHydrology Section, GFZ German Research Centre for Geosciences, 14473 Potsdam, GermanyHydrology Section, GFZ German Research Centre for Geosciences, 14473 Potsdam, GermanyHydrology Section, GFZ German Research Centre for Geosciences, 14473 Potsdam, GermanyHydrology Section, GFZ German Research Centre for Geosciences, 14473 Potsdam, GermanyHydrology Section, GFZ German Research Centre for Geosciences, 14473 Potsdam, GermanyHydrology Section, GFZ German Research Centre for Geosciences, 14473 Potsdam, GermanyInstitute of Environmental Science and Geography, University of Potsdam, 14476 Potsdam, Germany<p>Flood risk assessments are typically based on scenarios which assume homogeneous return periods of flood peaks throughout the catchment. This assumption is unrealistic for real flood events and may bias risk estimates for specific return periods. We investigate how three assumptions about the spatial dependence affect risk estimates: (i) spatially homogeneous scenarios (complete dependence), (ii) spatially heterogeneous scenarios (modelled dependence) and (iii) spatially heterogeneous but uncorrelated scenarios (complete independence). To this end, the model chain RFM (regional flood model) is applied to the Elbe catchment in Germany, accounting for the spatio-temporal dynamics of all flood generation processes, from the rainfall through catchment and river system processes to damage mechanisms. Different assumptions about the spatial dependence do not influence the expected annual damage (EAD); however, they bias the risk curve, i.e. the cumulative distribution function of damage. The widespread assumption of complete dependence strongly overestimates flood damage of the order of 100 % for return periods larger than approximately 200 years. On the other hand, for small and medium floods with return periods smaller than approximately 50 years, damage is underestimated. The overestimation aggravates when risk is estimated for larger areas. This study demonstrates the importance of representing the spatial dependence of flood peaks and damage for risk assessments.</p>https://www.nat-hazards-earth-syst-sci.net/20/967/2020/nhess-20-967-2020.pdf |
| spellingShingle | A. D. Metin A. D. Metin N. V. Dung K. Schröter S. Vorogushyn B. Guse H. Kreibich B. Merz B. Merz The role of spatial dependence for large-scale flood risk estimation Natural Hazards and Earth System Sciences |
| title | The role of spatial dependence for large-scale flood risk estimation |
| title_full | The role of spatial dependence for large-scale flood risk estimation |
| title_fullStr | The role of spatial dependence for large-scale flood risk estimation |
| title_full_unstemmed | The role of spatial dependence for large-scale flood risk estimation |
| title_short | The role of spatial dependence for large-scale flood risk estimation |
| title_sort | role of spatial dependence for large scale flood risk estimation |
| url | https://www.nat-hazards-earth-syst-sci.net/20/967/2020/nhess-20-967-2020.pdf |
| work_keys_str_mv | AT admetin theroleofspatialdependenceforlargescalefloodriskestimation AT admetin theroleofspatialdependenceforlargescalefloodriskestimation AT nvdung theroleofspatialdependenceforlargescalefloodriskestimation AT kschroter theroleofspatialdependenceforlargescalefloodriskestimation AT svorogushyn theroleofspatialdependenceforlargescalefloodriskestimation AT bguse theroleofspatialdependenceforlargescalefloodriskestimation AT hkreibich theroleofspatialdependenceforlargescalefloodriskestimation AT bmerz theroleofspatialdependenceforlargescalefloodriskestimation AT bmerz theroleofspatialdependenceforlargescalefloodriskestimation AT admetin roleofspatialdependenceforlargescalefloodriskestimation AT admetin roleofspatialdependenceforlargescalefloodriskestimation AT nvdung roleofspatialdependenceforlargescalefloodriskestimation AT kschroter roleofspatialdependenceforlargescalefloodriskestimation AT svorogushyn roleofspatialdependenceforlargescalefloodriskestimation AT bguse roleofspatialdependenceforlargescalefloodriskestimation AT hkreibich roleofspatialdependenceforlargescalefloodriskestimation AT bmerz roleofspatialdependenceforlargescalefloodriskestimation AT bmerz roleofspatialdependenceforlargescalefloodriskestimation |