| 11. |
- Andersson, Jan-Olov, 1966-, et al.
(författare)
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Spatial variation of wetlands and flux of dissolved organic carbon in boreal headwater streams
- 2008
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Ingår i: Hydrological Processes. - : Wiley. - 0885-6087 .- 1099-1085. ; :22, s. 1965-1975
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Tidskriftsartikel (refereegranskat)abstract
- In order to investigate the relation between water chemistry and functional landscape elements, spatial data sets of characteristics for 68 small (0·2–1·5 km2) boreal forest catchments in western central Sweden were analysed in a geographical information system (GIS). The geographic data used were extracted from official topographic maps. Water sampled four times at different flow situations was analysed chemically. This paper focuses on one phenomenon that has an important influence on headwater quality in boreal, coniferous forest streams: generation and export of dissolved organic carbon (DOC). It is known that wetland cover (bogs and fens) in the catchment is a major source of DOC. In this study, a comparison was made between a large number of headwater catchments with varying spatial locations and areas of wetlands. How this variation, together with a number of other spatial variables, influences the DOC flux in the streamwater was analysed by statistical methods. There were significant, but not strong, correlations between the total percentages of wetland area and DOC flux measured at a medium flow situation, but not at high flow. Neither were there any significant correlations between the percentage of wetland area connected to streams, nor the percentage of wetland area within a zone 50 m from the stream and the DOC flux. There were, however, correlations between catchment mean slope and the DOC flux in all but one flow situations. This study showed that, considering geographical data retrieved from official sources, the topography of a catchment better explains the variation in DOC flux than the percentage and locations of distinct wetland areas. This emphasizes the need for high-resolution elevation models accurate enough to reveal the sources of DOC found in headwater streams.
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| 12. |
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| 13. |
- Andersson-Sköld, Yvonne, et al.
(författare)
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Effective and Sustainable Flood and Landslide Risk Reduction Measures : An Investigation of Two Assessment Frameworks
- 2016
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Ingår i: International Journal of Disaster Risk Science. - : Springer Science and Business Media LLC. - 2095-0055 .- 2192-6395. ; 7:4, s. 374-392
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Tidskriftsartikel (refereegranskat)abstract
- Natural events such as floods and landslides can have severe consequences. The risks are expected to increase, both as a consequence of climate change and due to increased vulnerabilities, especially in urban areas. Although preventive measures are often cost-effective, some measures are beneficial to certain values, while some may have negative impacts on other values.The aim of the study presented here was to investigate two frameworks used for assessing the effectiveness and sustainability of physical and nonphysical flood and landslide risk reduction measures. The study is based on literature, available information from authorities and municipalities, expert knowledge and experience, and stakeholder views and values. The results indicate that the risks for suboptimization or maladaptation are reduced if many aspects are included and a broad spectrum of stakeholders are involved.The sustainability assessment tools applied here can contribute to a more transparent and sustainable risk management process by assessing strategies and interventions with respect to both short- and long-term perspectives, including local impacts and wider environmental impacts caused by climate change, for example. The tools can also cover social and economic aspects. The assessment tools provide checklists that can support decision processes, thus allowing for more transparent decisions.
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| 14. |
- Andersson-Sköld, Yvonne, et al.
(författare)
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Landslide risk management : A brief overview and example from Sweden of current situation and climate change
- 2013
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Ingår i: International Journal of Disaster Risk Reduction. - : Elsevier. - 2212-4209. ; 3:March, s. 44-61
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Tidskriftsartikel (refereegranskat)abstract
- Landslide risk is a function of the probability of the event and its consequences. Previous research has shown that preventive measures to reduce the risk are preferred over reactive measures but, especially in developing countries, rarely undertaken. A contributing factor is the lack of evidence that preventive measures pay. This study includes a brief overview of landslide risk management in general and an investigation of the present risk management situation in Sweden based on interviews in 11 municipalities complemented with interviews in Norway. The result shows that climate change has become part of the general awareness and started to be taken into account in the municipal spatial planning. Landslide susceptibility maps and databases are useful tools in the complex spatial planning. The results indicate that the application of landslide susceptibility and risk maps as previously applied for preventive measures and spatial planning in the landslide prone area Gota alv river valley have been cost effective. Improved documentation and more active communication among different stakeholders would, however, contribute to more effective landslide management.
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| 15. |
- Bergman, Ramona, et al.
(författare)
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Efficiency of preventive actions for landslides and flooding : evaluation of Scandinavian practices
- 2011
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Konferensbidrag (refereegranskat)abstract
- The results presented here covers natural hazards with focus on land slides and flooding. The results are based on Swedish/Scandinavian contexts. Natural events such as erosion, flooding and land slides are common, but the number of accidents (events causing severe negative impact) is rare. Therefore, in such analysis there is limited data and other information available which can be used for example in statistical analysis of actions and their effects. Instead, the analysis must be based on other information. The analysis may have to include aspects that only can be assessed by scenario and "what-if" analyses.In this project the main method has been interviews with officials in Swedish municipalities and national agencies in Sweden and Norway. In all municipalities, one politician and officials working with planning and rescue service have been interviewed. The study covers hazard and risk mapping, follow up of such maps, physical planning and lessons learned from previous events and activities.The final outcome of the research will be a review of what is found to be well functioning, identification of weak points and recommendations for the management of landslides, erosion and flooding. The present results indicate that hazard/risk maps are of great importance, but the knowledge about the maps and how to use them varies depending on who you ask and between municipalities. Most officials in municipalities are aware of climate change (CC) but, due to high uncertainties and since climate induced events such as natural hazards are rare, the issues are often not prioritized. Further, the results indicate that the documentation, communication and the responsibilities among different units is not always clear, having impacts on for example the knowledge transfer to new personnel.
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| 16. |
- Bergman, Ramona, et al.
(författare)
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Efficiency of preventive actions for landslides and flooding – evaluation of Scandinavian practices
- 2011
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Konferensbidrag (refereegranskat)abstract
- Preventive actions can be, and are frequently, taken to reduce accidents and their consequences in different ways. The MSB funded research programme "Effects of Society's Security actions" (ESS, 2009-2013) aims to study the relationship between such actions and their effects. The program is divided into three subgroups: Frequent accidents Natural hazards (such as flooding, erosion and landslide) Chemical and landfill accidents The results presented here covers natural hazards with focus on land slides and flooding. The results are based on Swedish/Scandinavian contexts. Natural events such as erosion,flooding and land slides are common, but the number of accidents (events causing severe negative impact) is rare. Therefore, in such analysis there is limited data and other information available which can be used for example in statistical analysis of actions and their effects. Instead, the analysis must be based on other information. Therefore, the analysis may have to include aspects that only can be assessed by scenario and "what-if" analyses. In this project the main method has been interviews with officials in Swedish municipalities and national agencies in Sweden and Norway. The two levels are chosen since policies are taken on national (or international) level, while the key actionsand actors are on the municipal level. The interviews cover experiences and potential scenarios. In all municipalities, one politician and officials working with planning and rescue service have been interviewed. The study covers hazard and risk mapping, follow up of such maps, physical planning and lessons learned from previous events and activities. The final outcome of the research will be a review of what is found to be well functioning, identification of weak points and recommendations for the management of landslides, erosion and flooding. The present results indicate that hazard/risk maps are of great importance, but the knowledge about the maps and how to use them varies depending on who you ask and between municipalities. Most officials in municipalities are aware of climate change (CC) but, due to high uncertainties and since climate induced events such as natural hazards are rare, the issues are often not prioritized. Further, the results indicate that the documentation, communication and the responsibilities among different units is not always clear, having impacts on for example the knowledge transfer to new personnel. Also databases can be useful tools. The project has found that the use of such tools varies between Norway and Sweden. The aim is to identify the reasons for such deviation. The mostly mentioned suggestions of improvement in the prevention process are increased knowledge, user friendly guidance, clear organisational structure and responsibilities and nationally provided ear marked funding for preventive measures.
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| 17. |
- Bishop, Kevin, et al.
(författare)
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Water storage in a till catchment. II : Implications of transmissivity feedback for flow paths and turnover times
- 2011
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Ingår i: Hydrological Processes. - : Wiley. - 0885-6087 .- 1099-1085. ; 25:25, s. 3950-3959
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Tidskriftsartikel (refereegranskat)abstract
- This paper explores the flow paths and turnover times within a catchment characterized by the transmissivity feedback mechanism where there is a strong increase in the saturated hydraulic conductivity towards the soil surface and precipitation inputs saturate progressively more superficial layers of the soil profile. The analysis is facilitated by the correlation between catchment water storage and groundwater levels, which made it possible to model the daily spatial distribution of water storage, both vertically in different soil horizons and horizontally across a 6300-m2 till catchment. Soil properties and episodic precipitation input dynamics, combined with the influence of topographic features, concentrate flow in the horizontal, vertical, and temporal dimensions. Within the soil profile, there was a vertical concentration of lateral flow to superficial soil horizons (upper 30?cm of the soil), where much of the annual flow occurred during runoff episodes. Overland flow from a limited portion of the catchment can contribute to peak flows but is not a necessary condition for runoff episodes. The spatial concentration of flow, and the episodic nature of runoff events, resulted in a strong and spatially structured differentiation of local flow velocities within the catchment. There were large differences in the time spent by the laterally flowing water at different depths, with turnover times of lateral flow across a 1-m-wide soil pedon ranging from under 1?h at 10- to 20-cm depth to a month at 70- to 80-cm depth. In many regards, the hydrology of this catchment appears typical of the hydrology in till soils, which are widespread in Fenno-Scandia. Copyright (c) 2011 John Wiley & Sons, Ltd.
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| 18. |
- Blumenthal, Barbara, 1969-, et al.
(författare)
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10 år efter Arvikaöversvämningen
- 2010
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Bok (övrigt vetenskapligt/konstnärligt)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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| 19. |
- Blumenthal, Barbara, 1969-
(författare)
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Nederbördsintensitet och andra faktorer som påverkar skyfallsskador
- 2018
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- I Sverige inträffar många skyfall och intensiva regn under sommarmånaderna. Det finns inga uppenbara geografiska mönster, vilket är en skillnad gentemot älv- eller sjööversvämningar där det vanligtvis är känt vilka områden som kan komma att översvämmas vid en viss vattennivå eller ett visst vattenflöde. För individer och samhällsaktörer innebär en skyfallshändelse i många fall en stor överraskning då skyfall utvecklas snabbt och dagens meteorologiska prognossystem i stort inte lyckas att prognosticera extrema regn korrekt med avseende på mängd, tid och plats. Vädervarningar kommer med kort varsel eller uteblir helt. Konsekvenserna av intensiv nederbörd och skyfall är främst översvämningar och erosionsskador på byggnader och infrastruktur, men även störningar och avbrott i olika samhällsfunktioner som kan påverka samhället och individer utanför det drabbade området.I denna avhandling har 15 år av försäkringsskadedata använts för att undersöka samband mellan nederbördsintensitet och skyfallsskador. Även påverkan av andra faktorer som topografi, bebyggelse och socioekonomiska aspekter har undersökts. Resultaten visar att regnintensitet under ett 60 minuters intervall i kombination med korta perioder av extrem intensitet, tillsammans med topografiska faktorer spelar en betydande roll vid uppkomsten av skador.
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| 20. |
- Blumenthal, Barbara, 1969-, et al.
(författare)
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The impact of intense rainfall on insurance losses in two Swedish cities
- 2018
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Ingår i: Journal of Flood Risk Management. - Hoboken : Wiley-Blackwell. - 1753-318X. ; 12:S2, s. 1-13
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Tidskriftsartikel (refereegranskat)abstract
- While a major part of previous research in the field of flood damage has focused on water depth as the most important causal factor, little attention has been paid to the role of rainfall intensity. As a test, this paper used correlation and regression analyses to investigate rainfall intensity as a factor affecting flood damage. For a time period of 15 years, the relationship between insurance losses caused by floods and rainfall intensity data from rain gauges were examined in two Swedish cities. Another objective was to find an approach for damage functions based on rainfall intensity as explanatory variable. Using linear regression, two approaches with considerable high degrees of explanation were found – one based on an exponential function and one on a power function. Using a lower limit for rainfall intensity, the approaches reached degrees of explanation between 30 and 78 %. From this study it was concluded that rainfall intensity during the summer months and the occurrence of insurance damages per day caused by floods were correlated and further that rainfall intensity has a great potential to explain urban flood damages. In the future, additional studies are needed to validate the proposed methods and integrate other flood damage affecting factors in the approach.
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