GIS-based debris flow source and runout susceptibility assessment from DEM data – a case study in NW Nicaragua

Abstract

Abstract. 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.Correspondence to: M. Guinau (mguinau@ub.edu)The study of terrain failure and runout susceptibility enabled us to obtain a spatial prediction for landslides, which could contribute to landslide risk mitigation.

Influence of check dams on debris-flow run-out intensity

“…Campbell, 1974Campbell, , 1975Lumb, 1975;Okuda et al, 1980;Caine, 1980;Crozier and Eyles, 1980;Cannon and Ellen, 1985;Wieczorek, 1987). Other studies were conducted through a "spatial approach" in order to define the areas which could potentially trigger a debris flow (the susceptibility) (Montgomery and Dietrich, 1994;Iovine et al, 2003;Hürlimann et al, 2006;Guinau et al, 2007).…”

Debris flow hazard modelling on medium scale: Valtellina di Tirano, Italy

“…Unlike other models simulating flow over the DEM (e.g. TauDEM; Guinau et al, 2007), Flow-R takes the advantage of multiple flow direction calculation for debris flow spreading. As the aim of this study was to prepare a debris flow hazard map at medium scale, the volume of debris flow was neglected.…”

A simple qualitative approach for mapping regional landslide susceptibility in the Faroe Islands

“…Qualitative approaches include landslide inventory mapping or expert evaluation (Malgot and Mahr, 1979;Ives and Messerli, 1981;Rupke et al, 1988;Wachal and Hudak, 2000;Morton et al, 2003;Sarkar and Anbalagan, 2008), while quantitative approaches can be divided into mechanistic (Terlien et al, 1995;Wu and Sidle, 1995;Alcantara-Ayala, 2004;Collins and Znidarcic, 2004;Dahl, 2007) and statistical methods Domínguez-Cuesta et al, 2007;Guinau et al, 2007;Magliulo et al, 2008). Mapping landslide initiation susceptibility by the use of expert evaluation is the qualitative approach most broadly used (He and Beighley, 2008), and is also the method chosen for this paper.…”

“…In other words, a landslide susceptibility map points out areas, which are likely to hold landslides in the future (Brabb, 1984). Several authors have emphasized, that mapping landslide susceptibility should include both recognition of landslide initiation areas and an assessment of runout behavior of the landslide material Corominas et al, 2003;Hürlimann et al, 2006;Guinau et al, 2007).…”