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

Abstract

Abstract. The Faroe Islands in the North Atlantic Ocean are highly susceptible to landslides. Following recent landslide incidents, Jarðfeingi (Faroese Earth and Energy Directorate) has pointed out, that the risk of human lives or of property being lost or affected by landslides may be increasing. This paper aims at presenting and testing a simple qualitative approach for mapping regional landslide susceptibility in the Faroe Islands, using few key parameters. The susceptibility model holds information about both landslide initiation areas and runout zones. Landslide initiation areas are determined from slope angle thresholds (25 • -40 • ) and soil cover data, while runout zones are delineated using the angle of reach approach taking into account the presence/absence of geological benches in the runout path, which has not been considered in earlier studies. Data input is obtained from a landslide database containing 67 debris flows throughout the Faroe Islands. Angle of reach values differ significantly with the presence/absence of geological benches in the runout path. Two values of angle of reach, 21.5 • and 27.6 • , are used for calculating runout zones. The landslide susceptibility model is tested in a study area at the town of Klaksvík in the northern part of the Faroe Islands. A map validation comparing predicted susceptibility zones with a validation-dataset of 87 actual landslides in the study area reveal that 69% and 92%, respectively, of actual landslide initiation areas and runout zones are correctly predicted. Moreover 87% of the actual landslides are included in the overall predicted landslide susceptibility areas.Correspondence to: M.-P. J. Dahl (mpjd@ruc.dk)

Landslide Susceptibility Mapping Based on Selected Optimal Combination of Landslide Predisposing Factors in a Large Catchment

“…In sensitive regions of geological environment, the original structure of rock was damaged by frequent earthquakes, and loose debris mass gathered there. Geological environment instability is further aggravated in these areas, due to a combination of complicated geological structure, steep terrain, erosion of frequent heavy rain and human activities [1][2][3]. Owing to the diversity and uncertainty of landslide predisposing factors and high increase in incidence frequency, the potential threat of landslides is increased, which not only endangers the safety of life and property for the local population, but also results in huge damage to regional resources and environment [4,5].…”

Modeling the flow behavior of a simulated municipal solid waste

“…This angle has been frequently used to quantify the mobility of hazards such as landslides (Corominas 1996;Dai and Lee 2002;Dahl et al 2010) and debris flows (Simoni et al 2011;Kappes et al 2011;Prochaska et al 2008).…”

Collapsed material movement of deep-seated landslides caused by Typhoon Talas 2011 on the Kii Peninsula, Japan

“…widely used as an indicator of travel distance [Dahl et al ., 2010;Finlay et al ., 1999;Hsu, 1975;Nishiguchi et al ., 2012;Okura et al ., 2003;Rickenmann, 2005;Scheidegger, 1973;Usuki et al ., 2006], and is greatly influenced by topographic factors [Hattanji and Moriwaki, 2009;Okura et al ., 2003]. ECF (= Σ H /Σ L) is the ratio between relative height (Σ H ) and total travel length (Σ L) from the top of the failure zone to the end of the deposition zone (Fig.…”