Comparison between Topographic and Bathymetric LiDAR Terrain Models in Flood Inundation Estimations
Remotely sensed LiDAR data has allowed for more accurate flood map generation through hydraulic simulations. Topographic and bathymetric LiDARs are the two types of LiDAR used, of which the former cannot penetrate water bodies while the latter can. Usually, the topographic LiDAR is more available th...
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-01-01
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| Series: | Remote Sensing |
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| Online Access: | https://www.mdpi.com/2072-4292/14/1/227 |
| _version_ | 1827667748982882304 |
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| author | Mahmoud Omer Mahmoud Awadallah Ana Juárez Knut Alfredsen |
| author_facet | Mahmoud Omer Mahmoud Awadallah Ana Juárez Knut Alfredsen |
| author_sort | Mahmoud Omer Mahmoud Awadallah |
| collection | DOAJ |
| description | Remotely sensed LiDAR data has allowed for more accurate flood map generation through hydraulic simulations. Topographic and bathymetric LiDARs are the two types of LiDAR used, of which the former cannot penetrate water bodies while the latter can. Usually, the topographic LiDAR is more available than bathymetric LiDAR, and it is, therefore, a very interesting data source for flood mapping. In this study, we made comparisons between flood inundation maps from several flood scenarios generated by the HEC-RAS 2D model for 11 sites in Norway using both bathymetric and topographic terrain models. The main objective is to investigate the accuracy of the flood inundations generated from the plain topographic LiDAR, the links of the inaccuracies with geomorphic features, and the potential of using corrections for missing underwater geometry in the topographic LiDAR data to improve accuracy. The results show that the difference in inundation between topographic and bathymetric LiDAR models decreases with increasing the flood size, and this trend was found to be correlated with the amount of protection embankments in the reach. In reaches where considerable embankments are constructed, the difference between the inundations increases until the embankments are overtopped and then returns to the general trend. In addition, the magnitude of the inundation error was found to correlate positively with the sinuosity and embankment coverage and negatively with the angle of the bank. Corrections were conducted by modifying the flood discharge based on the flight discharge of the topographic LiDAR or by correcting the topographic LiDAR terrain based on the volume of the flight discharge, where the latter method generally gave better improvements. |
| first_indexed | 2024-03-10T03:23:38Z |
| format | Article |
| id | doaj.art-f600b5a89f3b4393b1f1e33c906d7cbc |
| institution | Directory Open Access Journal |
| issn | 2072-4292 |
| language | English |
| last_indexed | 2024-03-10T03:23:38Z |
| publishDate | 2022-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Remote Sensing |
| spelling | doaj.art-f600b5a89f3b4393b1f1e33c906d7cbc2023-11-23T12:15:09ZengMDPI AGRemote Sensing2072-42922022-01-0114122710.3390/rs14010227Comparison between Topographic and Bathymetric LiDAR Terrain Models in Flood Inundation EstimationsMahmoud Omer Mahmoud Awadallah0Ana Juárez1Knut Alfredsen2Department of Civil and Environmental Engineering, Norwegian University of Science and Technology, 7031 Trondheim, NorwayDepartment of Civil and Environmental Engineering, Norwegian University of Science and Technology, 7031 Trondheim, NorwayDepartment of Civil and Environmental Engineering, Norwegian University of Science and Technology, 7031 Trondheim, NorwayRemotely sensed LiDAR data has allowed for more accurate flood map generation through hydraulic simulations. Topographic and bathymetric LiDARs are the two types of LiDAR used, of which the former cannot penetrate water bodies while the latter can. Usually, the topographic LiDAR is more available than bathymetric LiDAR, and it is, therefore, a very interesting data source for flood mapping. In this study, we made comparisons between flood inundation maps from several flood scenarios generated by the HEC-RAS 2D model for 11 sites in Norway using both bathymetric and topographic terrain models. The main objective is to investigate the accuracy of the flood inundations generated from the plain topographic LiDAR, the links of the inaccuracies with geomorphic features, and the potential of using corrections for missing underwater geometry in the topographic LiDAR data to improve accuracy. The results show that the difference in inundation between topographic and bathymetric LiDAR models decreases with increasing the flood size, and this trend was found to be correlated with the amount of protection embankments in the reach. In reaches where considerable embankments are constructed, the difference between the inundations increases until the embankments are overtopped and then returns to the general trend. In addition, the magnitude of the inundation error was found to correlate positively with the sinuosity and embankment coverage and negatively with the angle of the bank. Corrections were conducted by modifying the flood discharge based on the flight discharge of the topographic LiDAR or by correcting the topographic LiDAR terrain based on the volume of the flight discharge, where the latter method generally gave better improvements.https://www.mdpi.com/2072-4292/14/1/227LiDARtopographicbathymetricflood inundationHEC-RAShydraulic modeling |
| spellingShingle | Mahmoud Omer Mahmoud Awadallah Ana Juárez Knut Alfredsen Comparison between Topographic and Bathymetric LiDAR Terrain Models in Flood Inundation Estimations Remote Sensing LiDAR topographic bathymetric flood inundation HEC-RAS hydraulic modeling |
| title | Comparison between Topographic and Bathymetric LiDAR Terrain Models in Flood Inundation Estimations |
| title_full | Comparison between Topographic and Bathymetric LiDAR Terrain Models in Flood Inundation Estimations |
| title_fullStr | Comparison between Topographic and Bathymetric LiDAR Terrain Models in Flood Inundation Estimations |
| title_full_unstemmed | Comparison between Topographic and Bathymetric LiDAR Terrain Models in Flood Inundation Estimations |
| title_short | Comparison between Topographic and Bathymetric LiDAR Terrain Models in Flood Inundation Estimations |
| title_sort | comparison between topographic and bathymetric lidar terrain models in flood inundation estimations |
| topic | LiDAR topographic bathymetric flood inundation HEC-RAS hydraulic modeling |
| url | https://www.mdpi.com/2072-4292/14/1/227 |
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