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Titel |
GIS-based debris flow source and runout susceptibility assessment from DEM data – a case study in NW Nicaragua |
VerfasserIn |
M. Guinau, I. Vilajosana, J. M. Vilaplana |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1561-8633
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Digitales Dokument |
URL |
Erschienen |
In: Natural Hazards and Earth System Science ; 7, no. 6 ; Nr. 7, no. 6 (2007-11-26), S.703-716 |
Datensatznummer |
250004816
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Publikation (Nr.) |
copernicus.org/nhess-7-703-2007.pdf |
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Zusammenfassung |
In October 1998, Hurricane Mitch triggered numerous landslides (mainly
debris flows) in Honduras and Nicaragua, resulting in a high death toll and
in considerable damage to property. The potential application of relatively
simple and affordable spatial prediction models for landslide hazard mapping
in developing countries was studied. Our attention was focused on a region
in NW Nicaragua, one of the most severely hit places during the Mitch event.
A landslide map was obtained at 1:10 000 scale in a Geographic Information
System (GIS) environment from the interpretation of aerial photographs and
detailed field work. In this map the terrain failure zones were
distinguished from the areas within the reach of the mobilized materials. A
Digital Elevation Model (DEM) with 20 m×20 m of pixel size was also employed
in the study area.
A comparative analysis of the terrain failures caused by Hurricane Mitch and
a selection of 4 terrain factors extracted from the DEM which, contributed
to the terrain instability, was carried out. Land propensity to failure was
determined with the aid of a bivariate analysis and GIS tools in a terrain
failure susceptibility map. In order to estimate the areas that could be
affected by the path or deposition of the mobilized materials, we considered
the fact that under intense rainfall events debris flows tend to travel long
distances following the maximum slope and merging with the drainage network.
Using the TauDEM extension for ArcGIS software we generated automatically
flow lines following the maximum slope in the DEM starting from the areas
prone to failure in the terrain failure susceptibility map. The areas
crossed by the flow lines from each terrain failure susceptibility class
correspond to the runout susceptibility classes represented in a runout
susceptibility map.
The study of terrain failure and runout susceptibility enabled us to obtain
a spatial prediction for landslides, which could contribute to landslide
risk mitigation. |
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