| 1. |
- Andersson-Sköld, Yvonne, et al.
(author)
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Landslide risk and climate change : economic assessment of consequenses in the Göta river valley
- 2011
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Conference paper (other academic/artistic)abstract
- According to climate change scenarios, Swedish summers will be drier, but in large parts of Sweden there will also be increased annual precipitation, more intensive precipitation and periods with increased water flows. In many areas the risk for landslides is expected to increase. In response to this the SGI, on commission of the Environmental ministry, has started a risk analysis for the Göta river valley. The results of the analysis will be used in the surveillance of the safety along the Göta river valley. The valley is one of the most frequent landslide valleys in Sweden.The area has a long history of anthropogenic activities such as settlements, shipping, industry, contaminated soil and infrastructure including large roads and railroads. A number of landslides occur every year. The landslide risk analysis of Göta river valley is performed by traditional technical risk analysis, i.e. a function of hazard probability and consequences of the hazard. Elements at risk in the valley include for example, human life, transport and other infrastructure, properties and industrial activities, contaminated land, agriculture and forestry, and intangibles such as biodiversity. Exposure, vulnerability and the monetary value related to the landslide are used to describe the consequence of the landslide.This paper shows the process and structure of this consequence analysis for natural hazards. The consequence analysis methodology can be applied generic both nationally and internationally and for several types of natural hazards such as landslides and flooding.
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| 2. |
- Blumenthal, Barbara, 1969-, et al.
(author)
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10 år efter Arvikaöversvämningen
- 2010
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Book (other academic/artistic)abstract
- Efter en mycket regnrik höst kulminerade vattennivån i Glafsfjorden den 29 november 2000 på drygt 3 m över normalnivån. De strandnära områdena i det värmländska Arvika sattes under vatten, vägnätet hotades, många mindre vägar fick stängas av och järnvägstrafiken ställdes in i över tre veckor. Samhällets krafter mobiliserades för att skydda fastigheter och infrastruktur. Många högt uppsatta besökare kom till Arvika för att se översvämningen med egna ögon. Läget var skarpt i en och en halv månad.Boken ger en inblick i den meteorologiska och hydrologiska bakgrunden av händelsen. Den beskriver händelseförloppet och skadorna som översvämningen orsakade. I en samhällsekonomisk genomgång summeras de direkta skadekostnaderna till 315 Mkr i 2009 års prisläge. Översvämningen följdes upp i ett stort antal utredningar och boken skildrar hur planerna till ett översvämningsskydd för staden växte fram. Den mänskliga dimensionen av händelsen förtydligas med berättelser av översvämningsdrabbade privatpersoner och intervjuer med kommunanställda.
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| 3. |
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| 4. |
- Grahn, Tonje
(author)
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A Nordic Perspective on Data Availability for Quantification of Losses due to Natural Hazards
- 2016
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Licentiate thesis (other academic/artistic)abstract
- Natural hazards cause enormous amounts of damage worldwide every year. Since 1994 more than 1.35 billion people have lost their lives and more than 116 million homes have been damaged. Understanding of disaster risk implies knowledge about vulnerability, capacity, exposure of persons and assets, hazard characteristics and the environment. Quantitative damage assessments are a fundamental part of disaster risk management. There are, however, substantial challenges when quantifying damage which depends on the diversity of hazards and the fact that one hazardous event can negatively impact a society in multiple ways. The overall aim of the thesis is to analyze the relationship between climate-related natural hazards and subsequent damage for the purpose of improving the prerequisite for quantitative risk assessments in the future. The thesis concentrates on two specific types of consequences due to two types of hazards, 1) damage to buildings caused by lake floods, and 2) loss of lives caused by quick clay landslides. Several causal relationships were established between risk factors and the extent of damages. Lake water levels increased the probability of structural building damage. Private damage reducing measures decreased the probability of structural building damage. Extent of damage decreased with distance to waterfront but increased with longer flood duration while prewar houses suffered lower flood damage compared to others. Concerning landslides, the number of fatalities increased when the number of humans in the exposed population increased. The main challenges to further damage estimation are data scarcity, insufficient detail level and the fact that the data are rarely systematically collected for scientific purposes. More efforts are needed to create structured, homogeneous and detailed damage databases with corresponding risk factors in order to further develop quantitative damage assessment of natural hazards in a Nordic perspective.
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| 5. |
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| 6. |
- Grahn, Tonje, et al.
(author)
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Assessment of data availability for the development of landslide fatality curves
- 2017
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In: Landslides. - : Springer Science and Business Media LLC. - 1612-510X .- 1612-5118. ; 14:3, s. 1113-1126
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Journal article (peer-reviewed)abstract
- Quick clay landslides are a special feature of Norwegian and Swedish geologies. Vibrations or small initial landslides can cause a quick clay layer to collapse and liquefy, resulting in rapid landslides with little or no time for evacuation, making them a real threat to human life. Research concentrating on damages due to landslides is scarce, and analyses of loss of human lives caused by quick clay landslides in the scientific literature are, to our knowledge, non-existing. Fatality quantification can complement landslide risk assessments and serves as guidance for policy choices when evaluating efficient risk-reducing measures. The objectives of this study were to assess and analyze available damage information in an existing data set of 66 historical landslide events that occurred in Norway and Sweden between 1848 and 2009, and access its applicability for quantifying loss of human life caused by quick clay landslides. Fatality curves were estimated as functions of the number of exposed persons per landslide. Monte Carlo simulations were used to account for the uncertainties in the number of people actually exposed. The results of the study imply that the quick clay fatality curves are non-linear, indicating that the probability of losing lives increases exponentially when the number of exposed persons increases. Potential factors affecting human susceptibility to landslides (e.g., landslide-, area-, or individual-specific characteristics) could not be satisfyingly quantified based on available historical records. Future research should concentrate on quantifying susceptibility factors that can further explain human vulnerability to quick clay landslides.
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| 7. |
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| 8. |
- Grahn, Tonje, et al.
(author)
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Damage assessment of lake floods : Insured damage to private property during two lake floods in Sweden 2000/2001
- 2014
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In: International Journal of Disaster Risk Reduction. - : Elsevier. - 2212-4209. ; 10, s. 305-314
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Journal article (peer-reviewed)abstract
- This study analyses empirical data on the direct damage impact of lake floods using insurance claims for 195 private buildings. A relationship between lake water levels and insurance payments is established, but the estimated economic effects are small. Building damage also occurs in fringe areas that are not reached by surface water, which indicates a complex interplay between several factors influencing the degree of damage. Large lake floods occur over an extended time span (months). Their duration, as well as possible wind effects, should be taken into account in flood risk assessment. The slow onset of lake floods facilitates implementation of private damage-reducing measures in addition to public mitigation efforts. Private damage-reducing measures decrease the risk of structural damage to buildings, easing recovery for homeowners and society as a whole. Insurance companies can gain from investing in public flood awareness programmes and by providing information to their insurance holders on how to reduce property vulnerability in emergency situations.
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| 9. |
- Grahn, Tonje, 1976-, et al.
(author)
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Households (un)willingness to perform private flood risk reduction : Results from a Swedish survey
- 2019
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In: Safety Science. - : Elsevier. - 0925-7535 .- 1879-1042. ; 116, s. 127-136
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Journal article (peer-reviewed)abstract
- This study applies the protection motivation theory (PMT) in analysing homeowners’ flood risk perception and their risk reduction behaviour. A survey was completed by 1143 households in flood-prone residential areas in Sweden. Respondents were asked about their flood experience, their beliefs about their future private flood risk, their trust in public risk reduction and their perception of how responsibility for flood risk reduction is divided between different governmental and private institutions. This study finds that homeowners that have implemented private flood risk reduction (FRR) had to a larger extent been exposed to floods in the past and they considered public FRR to be insufficient. They also had a greater sense of responsibility and believed they had considerable knowledge on how to reduce their private flood risk. Respondents were also asked about their preferences for performing 15 specific private risk reducing measures. The most frequent answer given by homeowners was (1) they do not have the knowledge needed to evaluate the measures. (2) They have evaluated the measures and deemed that the measures will not be able to effectively reduce their private flood risk. To facilitate and exploit the flood risk reduction potential of households, this study identifies the following four areas of flood risk management that need to be better communicated to residents in vulnerable residential areas: Objective flood risk, response efficacy regarding private and public FRR measures, skills that can increase homeowners’ self-efficacy, and the actual responsibility distribution by law concerning private property flood risk reduction.
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| 10. |
- Grahn, Tonje, 1976-, et al.
(author)
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Insured flood damage in Sweden, 1987-2013
- 2018
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In: Journal of Flood Risk Management. - : Blackwell Publishing. - 1753-318X. ; 12:3
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Journal article (peer-reviewed)abstract
- This study uses insurance claims as a proxy for property damage to analyse flood damage in Sweden between the years 1987 and 2013. The number of compensated insurance claims per year has risen rapidly during this period. As much as 70% of the claims are caused by flood damage occurring during the summer months June, July, and August, when intense rain with low predictability is common. To explore the damage trend a time series cross sectional analysis using four different fixed effect models was applied to the data set. Due to data scarcity, the time series had to be limited to 16years and contain a total of 304 damage observations. The potentially explanatory climate related factor extreme rain, defined as >6 mm/15min, and the socioeconomic factors gross regional product (GRP) per capita and housing stock were tested as explanatory factors. The GRP per capita and housing stock were found to be significant in two regression models. The estimated effect of extreme rainfall events exceeded the effects of GRP per capita and housing stock in the models. Extreme rain was robust to model specification and was found to have a highly significant impact on Swedish flood damage.
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