Dealing with deep uncertainties in landslide modelling for disaster risk reduction under climate change

Landslides have large negative economic and societal impacts, including loss of life and damage to infrastructure. Slope stability assessment is a vital tool for landslide risk management, but high levels of uncertainty often challenge its usefulness. Uncertainties are associated with the numerical...

Full description

Bibliographic Details
Main Authors: S. Almeida, E. A. Holcombe, F. Pianosi, T. Wagener
Format: Article
Language:English
Published: Copernicus Publications 2017-02-01
Series:Natural Hazards and Earth System Sciences
Online Access:http://www.nat-hazards-earth-syst-sci.net/17/225/2017/nhess-17-225-2017.pdf
_version_ 1811263918614511616
author S. Almeida
E. A. Holcombe
F. Pianosi
T. Wagener
author_facet S. Almeida
E. A. Holcombe
F. Pianosi
T. Wagener
author_sort S. Almeida
collection DOAJ
description Landslides have large negative economic and societal impacts, including loss of life and damage to infrastructure. Slope stability assessment is a vital tool for landslide risk management, but high levels of uncertainty often challenge its usefulness. Uncertainties are associated with the numerical model used to assess slope stability and its parameters, with the data characterizing the geometric, geotechnic and hydrologic properties of the slope, and with hazard triggers (e.g. rainfall). Uncertainties associated with many of these factors are also likely to be exacerbated further by future climatic and socio-economic changes, such as increased urbanization and resultant land use change. In this study, we illustrate how numerical models can be used to explore the uncertain factors that influence potential future landslide hazard using a bottom-up strategy. Specifically, we link the Combined Hydrology And Stability Model (CHASM) with sensitivity analysis and Classification And Regression Trees (CART) to identify critical thresholds in slope properties and climatic (rainfall) drivers that lead to slope failure. We apply our approach to a slope in the Caribbean, an area that is naturally susceptible to landslides due to a combination of high rainfall rates, steep slopes, and highly weathered residual soils. For this particular slope, we find that uncertainties regarding some slope properties (namely thickness and effective cohesion of topsoil) are as important as the uncertainties related to future rainfall conditions. Furthermore, we show that 89 % of the expected behaviour of the studied slope can be characterized based on only two variables – the ratio of topsoil thickness to cohesion and the ratio of rainfall intensity to duration.
first_indexed 2024-04-12T19:53:46Z
format Article
id doaj.art-dd8b0432a7e44c4ebe5fb02640e35e46
institution Directory Open Access Journal
issn 1561-8633
1684-9981
language English
last_indexed 2024-04-12T19:53:46Z
publishDate 2017-02-01
publisher Copernicus Publications
record_format Article
series Natural Hazards and Earth System Sciences
spelling doaj.art-dd8b0432a7e44c4ebe5fb02640e35e462022-12-22T03:18:43ZengCopernicus PublicationsNatural Hazards and Earth System Sciences1561-86331684-99812017-02-0117222524110.5194/nhess-17-225-2017Dealing with deep uncertainties in landslide modelling for disaster risk reduction under climate changeS. Almeida0E. A. Holcombe1F. Pianosi2T. Wagener3Department of Civil Engineering, University of Bristol, Bristol, BS8 1TR, UKDepartment of Civil Engineering, University of Bristol, Bristol, BS8 1TR, UKDepartment of Civil Engineering, University of Bristol, Bristol, BS8 1TR, UKDepartment of Civil Engineering, University of Bristol, Bristol, BS8 1TR, UKLandslides have large negative economic and societal impacts, including loss of life and damage to infrastructure. Slope stability assessment is a vital tool for landslide risk management, but high levels of uncertainty often challenge its usefulness. Uncertainties are associated with the numerical model used to assess slope stability and its parameters, with the data characterizing the geometric, geotechnic and hydrologic properties of the slope, and with hazard triggers (e.g. rainfall). Uncertainties associated with many of these factors are also likely to be exacerbated further by future climatic and socio-economic changes, such as increased urbanization and resultant land use change. In this study, we illustrate how numerical models can be used to explore the uncertain factors that influence potential future landslide hazard using a bottom-up strategy. Specifically, we link the Combined Hydrology And Stability Model (CHASM) with sensitivity analysis and Classification And Regression Trees (CART) to identify critical thresholds in slope properties and climatic (rainfall) drivers that lead to slope failure. We apply our approach to a slope in the Caribbean, an area that is naturally susceptible to landslides due to a combination of high rainfall rates, steep slopes, and highly weathered residual soils. For this particular slope, we find that uncertainties regarding some slope properties (namely thickness and effective cohesion of topsoil) are as important as the uncertainties related to future rainfall conditions. Furthermore, we show that 89 % of the expected behaviour of the studied slope can be characterized based on only two variables – the ratio of topsoil thickness to cohesion and the ratio of rainfall intensity to duration.http://www.nat-hazards-earth-syst-sci.net/17/225/2017/nhess-17-225-2017.pdf
spellingShingle S. Almeida
E. A. Holcombe
F. Pianosi
T. Wagener
Dealing with deep uncertainties in landslide modelling for disaster risk reduction under climate change
Natural Hazards and Earth System Sciences
title Dealing with deep uncertainties in landslide modelling for disaster risk reduction under climate change
title_full Dealing with deep uncertainties in landslide modelling for disaster risk reduction under climate change
title_fullStr Dealing with deep uncertainties in landslide modelling for disaster risk reduction under climate change
title_full_unstemmed Dealing with deep uncertainties in landslide modelling for disaster risk reduction under climate change
title_short Dealing with deep uncertainties in landslide modelling for disaster risk reduction under climate change
title_sort dealing with deep uncertainties in landslide modelling for disaster risk reduction under climate change
url http://www.nat-hazards-earth-syst-sci.net/17/225/2017/nhess-17-225-2017.pdf
work_keys_str_mv AT salmeida dealingwithdeepuncertaintiesinlandslidemodellingfordisasterriskreductionunderclimatechange
AT eaholcombe dealingwithdeepuncertaintiesinlandslidemodellingfordisasterriskreductionunderclimatechange
AT fpianosi dealingwithdeepuncertaintiesinlandslidemodellingfordisasterriskreductionunderclimatechange
AT twagener dealingwithdeepuncertaintiesinlandslidemodellingfordisasterriskreductionunderclimatechange