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Titel |
Evaluating scale and roughness effects in urban flood modelling using terrestrial LIDAR data |
VerfasserIn |
H. Ozdemir, C. C. Sampson, G. A. M. Almeida, P. D. Bates |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1027-5606
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Digitales Dokument |
URL |
Erschienen |
In: Hydrology and Earth System Sciences ; 17, no. 10 ; Nr. 17, no. 10 (2013-10-17), S.4015-4030 |
Datensatznummer |
250085961
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Publikation (Nr.) |
copernicus.org/hess-17-4015-2013.pdf |
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Zusammenfassung |
This paper evaluates the results of benchmark testing a new inertial
formulation of the St. Venant equations, implemented within the LISFLOOD-FP
hydraulic model, using different high resolution terrestrial LiDAR data
(10 cm, 50 cm and 1 m) and roughness conditions (distributed and composite) in
an urban area. To examine these effects, the model is applied to a
hypothetical flooding scenario in Alcester, UK, which experienced surface
water flooding during summer 2007. The sensitivities of simulated water
depth, extent, arrival time and velocity to grid resolutions and different
roughness conditions are analysed. The results indicate that increasing the
terrain resolution from 1 m to 10 cm significantly affects modelled water
depth, extent, arrival time and velocity. This is because hydraulically
relevant small scale topography that is accurately captured by the
terrestrial LIDAR system, such as road cambers and street kerbs, is better
represented on the higher resolution DEM. It is shown that altering surface
friction values within a wide range has only a limited effect and is not
sufficient to recover the results of the 10 cm simulation at 1 m resolution.
Alternating between a uniform composite surface friction value (n = 0.013)
or a variable distributed value based on land use has a greater effect on
flow velocities and arrival times than on water depths and inundation
extent. We conclude that the use of extra detail inherent in terrestrial
laser scanning data compared to airborne sensors will be advantageous for
urban flood modelling related to surface water, risk analysis and planning
for Sustainable Urban Drainage Systems (SUDS) to attenuate flow. |
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