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| Titel |
Assessing the impact of different sources of topographic data on 1-D hydraulic modelling of floods |
| VerfasserIn |
A. Md Ali, D. P. Solomatine, G. Di Baldassarre |
| 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 ; 19, no. 1 ; Nr. 19, no. 1 (2015-01-30), S.631-643 |
| Datensatznummer |
250120613
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| Publikation (Nr.) |
 copernicus.org/hess-19-631-2015.pdf |
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| Zusammenfassung |
| Topographic data, such as digital elevation models (DEMs), are essential
input in flood inundation modelling. DEMs can be derived from several
sources either through remote sensing techniques (spaceborne or airborne
imagery) or from traditional methods (ground survey). The Advanced
Spaceborne Thermal Emission and Reflection Radiometer (ASTER), the Shuttle
Radar Topography Mission (SRTM), the light detection and ranging (lidar),
and topographic contour maps are some of the most commonly used sources of
data for DEMs. These DEMs are characterized by different precision and
accuracy. On the one hand, the spatial resolution of low-cost DEMs from
satellite imagery, such as ASTER and SRTM, is rather coarse (around 30 to
90 m). On the other hand, the lidar technique is able to produce high-resolution DEMs (at around 1 m), but at a much higher cost. Lastly, contour
mapping based on ground survey is time consuming, particularly for higher
scales, and may not be possible for some remote areas. The use of these
different sources of DEM obviously affects the results of flood inundation
models. This paper shows and compares a number of 1-D hydraulic models
developed using HEC-RAS as model code and the aforementioned sources of DEM
as geometric input. To test model selection, the outcomes of the 1-D models
were also compared, in terms of flood water levels, to the results of 2-D
models (LISFLOOD-FP). The study was carried out on a reach of the Johor
River, in Malaysia. The effect of the different sources of DEMs (and
different resolutions) was investigated by considering the performance of
the hydraulic models in simulating flood water levels as well as inundation
maps. The outcomes of our study show that the use of different DEMs has
serious implications to the results of hydraulic models. The outcomes also
indicate that the loss of model accuracy due to re-sampling the highest
resolution DEM (i.e. lidar 1 m) to lower resolution is much less than the loss of model accuracy due to the use of low-cost DEM that have not
only a lower resolution, but also a lower quality. Lastly, to better explore
the sensitivity of the 1-D hydraulic models to different DEMs, we performed
an uncertainty analysis based on the GLUE methodology. |
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