Magnitude-frequency characteristics and preparatory factors for spatial debris-slide distribution in the northern Faroe Islands

Mads-Peter Jakob Dahl, Niels H. Jensen, Anita Veihe, Lis Mortensen

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

Resumé

The Faroe Islands in the North Atlantic Ocean are highly susceptible to debris-avalanches and debris-flows originating from debris-slide activity in shallow colluvial soils. To provide data for hazard and risk assessment of debris-avalanches and debris-flows, this study aims at quantifying the magnitude and frequency of their debris-slide origins as well as identifying which preparatory factors are responsible for the spatial debris-slide distribution in the landscape. For that purpose a debris-slide inventory was generated from aerial photo interpretation (API), fieldwork and anecdotal sources, covering a 159 km(2) study area in the northern Faroe Islands. A magnitude-cumulative frequency (MCF) curve was derived to predict magnitude dependant debris-slide frequencies, while preparatory factors responsible for spatial debris-slide distribution were quantified through GIS-supported discriminant function analysis (DFA). Nine factors containing geological (lithology, dip), geomorphological (slope angle, altitude, aspect; plan and profile curvature) and land use (infield/outfield, sheep density) information were included in the multivariate analysis. Debris-slides larger than 100 m(2) with magnitude expressed as topographic scar area can be predicted from the power-law function: Y = 936.26X(-1277), r(2) = 0.98 while a physical explanation is preferred for the roll-over pattern of smaller slope failures. The DFA is able to correctly classify app. 70% of the modeled terrain units into their pre-determined stable/unstable groups. Preparatory factors responsible for the spatial debris-slide distribution are aspect, slope angle, sheep density, plan curvature and altitude, while influence of the remaining factors is negligible. (C) 2012 Elsevier B.V. All rights reserved.
OriginalsprogEngelsk
TidsskriftGeomorphology
Vol/bind188
Sider (fra-til)3-11
ISSN0169-555X
DOI
StatusUdgivet - 2013

Emneord

  • Debris-slides
  • Flow-type landslides
  • The Faroe Islands
  • Aerial photograph interpretation
  • Magnitude-frequency analysis
  • Discriminant function analysis

Citer dette

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abstract = "The Faroe Islands in the North Atlantic Ocean are highly susceptible to debris-avalanches and debris-flows originating from debris-slide activity in shallow colluvial soils. To provide data for hazard and risk assessment of debris-avalanches and debris-flows, this study aims at quantifying the magnitude and frequency of their debris-slide origins as well as identifying which preparatory factors are responsible for the spatial debris-slide distribution in the landscape. For that purpose a debris-slide inventory was generated from aerial photo interpretation (API), fieldwork and anecdotal sources, covering a 159 km(2) study area in the northern Faroe Islands. A magnitude-cumulative frequency (MCF) curve was derived to predict magnitude dependant debris-slide frequencies, while preparatory factors responsible for spatial debris-slide distribution were quantified through GIS-supported discriminant function analysis (DFA). Nine factors containing geological (lithology, dip), geomorphological (slope angle, altitude, aspect; plan and profile curvature) and land use (infield/outfield, sheep density) information were included in the multivariate analysis. Debris-slides larger than 100 m(2) with magnitude expressed as topographic scar area can be predicted from the power-law function: Y = 936.26X(-1277), r(2) = 0.98 while a physical explanation is preferred for the roll-over pattern of smaller slope failures. The DFA is able to correctly classify app. 70{\%} of the modeled terrain units into their pre-determined stable/unstable groups. Preparatory factors responsible for the spatial debris-slide distribution are aspect, slope angle, sheep density, plan curvature and altitude, while influence of the remaining factors is negligible. (C) 2012 Elsevier B.V. All rights reserved.",
keywords = "Debris-slides, Flow-type landslides, The Faroe Islands, Aerial photograph interpretation, Magnitude-frequency analysis, Discriminant function analysis, Debris-slides, Flow-type landslides, The Faroe Islands, Aerial photograph interpretation, Magnitude-frequency analysis, Discriminant function analysis",
author = "Dahl, {Mads-Peter Jakob} and Jensen, {Niels H.} and Anita Veihe and Lis Mortensen",
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Magnitude-frequency characteristics and preparatory factors for spatial debris-slide distribution in the northern Faroe Islands. / Dahl, Mads-Peter Jakob; Jensen, Niels H.; Veihe, Anita; Mortensen, Lis.

I: Geomorphology, Bind 188, 2013, s. 3-11.

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

TY - JOUR

T1 - Magnitude-frequency characteristics and preparatory factors for spatial debris-slide distribution in the northern Faroe Islands

AU - Dahl, Mads-Peter Jakob

AU - Jensen, Niels H.

AU - Veihe, Anita

AU - Mortensen, Lis

PY - 2013

Y1 - 2013

N2 - The Faroe Islands in the North Atlantic Ocean are highly susceptible to debris-avalanches and debris-flows originating from debris-slide activity in shallow colluvial soils. To provide data for hazard and risk assessment of debris-avalanches and debris-flows, this study aims at quantifying the magnitude and frequency of their debris-slide origins as well as identifying which preparatory factors are responsible for the spatial debris-slide distribution in the landscape. For that purpose a debris-slide inventory was generated from aerial photo interpretation (API), fieldwork and anecdotal sources, covering a 159 km(2) study area in the northern Faroe Islands. A magnitude-cumulative frequency (MCF) curve was derived to predict magnitude dependant debris-slide frequencies, while preparatory factors responsible for spatial debris-slide distribution were quantified through GIS-supported discriminant function analysis (DFA). Nine factors containing geological (lithology, dip), geomorphological (slope angle, altitude, aspect; plan and profile curvature) and land use (infield/outfield, sheep density) information were included in the multivariate analysis. Debris-slides larger than 100 m(2) with magnitude expressed as topographic scar area can be predicted from the power-law function: Y = 936.26X(-1277), r(2) = 0.98 while a physical explanation is preferred for the roll-over pattern of smaller slope failures. The DFA is able to correctly classify app. 70% of the modeled terrain units into their pre-determined stable/unstable groups. Preparatory factors responsible for the spatial debris-slide distribution are aspect, slope angle, sheep density, plan curvature and altitude, while influence of the remaining factors is negligible. (C) 2012 Elsevier B.V. All rights reserved.

AB - The Faroe Islands in the North Atlantic Ocean are highly susceptible to debris-avalanches and debris-flows originating from debris-slide activity in shallow colluvial soils. To provide data for hazard and risk assessment of debris-avalanches and debris-flows, this study aims at quantifying the magnitude and frequency of their debris-slide origins as well as identifying which preparatory factors are responsible for the spatial debris-slide distribution in the landscape. For that purpose a debris-slide inventory was generated from aerial photo interpretation (API), fieldwork and anecdotal sources, covering a 159 km(2) study area in the northern Faroe Islands. A magnitude-cumulative frequency (MCF) curve was derived to predict magnitude dependant debris-slide frequencies, while preparatory factors responsible for spatial debris-slide distribution were quantified through GIS-supported discriminant function analysis (DFA). Nine factors containing geological (lithology, dip), geomorphological (slope angle, altitude, aspect; plan and profile curvature) and land use (infield/outfield, sheep density) information were included in the multivariate analysis. Debris-slides larger than 100 m(2) with magnitude expressed as topographic scar area can be predicted from the power-law function: Y = 936.26X(-1277), r(2) = 0.98 while a physical explanation is preferred for the roll-over pattern of smaller slope failures. The DFA is able to correctly classify app. 70% of the modeled terrain units into their pre-determined stable/unstable groups. Preparatory factors responsible for the spatial debris-slide distribution are aspect, slope angle, sheep density, plan curvature and altitude, while influence of the remaining factors is negligible. (C) 2012 Elsevier B.V. All rights reserved.

KW - Debris-slides

KW - Flow-type landslides

KW - The Faroe Islands

KW - Aerial photograph interpretation

KW - Magnitude-frequency analysis

KW - Discriminant function analysis

KW - Debris-slides

KW - Flow-type landslides

KW - The Faroe Islands

KW - Aerial photograph interpretation

KW - Magnitude-frequency analysis

KW - Discriminant function analysis

U2 - 10.1016/j.geomorph.2012.09.015

DO - 10.1016/j.geomorph.2012.09.015

M3 - Journal article

VL - 188

SP - 3

EP - 11

JO - Geomorphology

JF - Geomorphology

SN - 0169-555X

ER -