Papers by Dilani Dassanayake
The International Journal of Ocean and Climate Systems, Dec 1, 2012
German coasts are often affected by extreme storm surges which have already led to major damages ... more German coasts are often affected by extreme storm surges which have already led to major damages along the coastline in the past. The joint research project "XtremRisK" was initiated with the main objective of enhancing the knowledge with respect to the uncertainties of extreme storm surge predictions as well as quantifying exemplarily the flood risk under current conditions and future climate scenarios for two pilot sites in Germany: Sylt Island representative for an open coast and Hamburg for an estuarine urban area. Flood risk is generally determined by the product of the flooding probability and the possible losses associated with the flood event. Flood losses are categorized as tangible and intangible depending on whether or not the losses can be assessed in monetary values. Up to date, intangible loses are not or only partially incorporated in flood risk analysis due to the lack of appropriate evaluation and integration methodologies. This study focuses on developing methodologies for the evaluation of intangible losses due to flooding and for their integration with tangible losses in flood risk analysis 1. INTRODUCTION Coastal flooding has become one of the most devastating natural disasters in the recent past and it is expected to significantly increase due to the possible impact of climate change on sea level rise and extreme storm surge events (IPCC 2007). Furthermore, human settlements are more concentrated in the coastal zones due to the economic benefits arising from ocean navigation, coastal fisheries, tourism and recreation. Around 40% of the world's population lives within 100 km of the coast which may lead to an increase of the damage due to coastal flooding (Stål et al. 2008). Therefore, the development of methodologies for the estimation of coastal flood risk has become an urgent need for the identification and implementation of proper coastal protection measures. The joint research project "XtremRisK" (Extreme storm surges at open coasts and estuarine areas: risk assessment and mitigation under climate change aspects) was initiated in October 2008 by the last author, with the main objective of enhancing the knowledge with respect to the uncertainties of extreme storm surge predictions as well as quantifying the overall flood risks (Oumeraci et al. 2009). Within this project, risk analysis is exemplarily carried out for two pilot sites in Germany: Hamburg and Sylt (Figure 1a). Hamburg is a typical example for an urban estuarine area (Figure 1b), while the island of Sylt at the North Sea represents a typical example for an open coast (Figure 1c).Within these two pilot sites, Hamburg-Wilhelmsburg, which is located in the Elbe estuary, and two study areas at Sylt Island; Westerland and Hörnum, were selected for a detailed study.
Proceedings of ... Conference on Coastal Engineering, Dec 14, 2012
The expected climate change and the associated possible increase of the frequency and magnitude o... more The expected climate change and the associated possible increase of the frequency and magnitude of extreme storm surges may lead to larger storm surge hazards than have been observed in the past. Therefore, the German XtremRisK project aims to improve the understanding of the impact of extreme storm surges under current and future climate conditions by conducting an integrated flood risk analysis for two selected pilot sites in Germany which may be representative for an open coast (Sylt Island) and a megacity in an estuarine area (Hamburg). The research has also been focused on developing and improving the knowledge, methods and models for the assessment of intangible losses (social and environmental), their spatial modelling as well as their integration with direct and indirect economic losses. After a brief introduction into the integrated flood risk analysis being implemented, the paper describes the methodologies and discusses the results with a focus on the modelling of tangible and intangible losses in the pilot site Hamburg-Wilhelmsburg.
A brief overview of the joint research project XtremRisK is given. The project has been focusing ... more A brief overview of the joint research project XtremRisK is given. The project has been focusing on developing/improving/expanding the knowledge, methods and models with respect to (i) physically possible extreme storm surge for current conditions and scenarios for climate change, (ii) failure mechanisms of flood defences, (iii) assessment of intangible losses (social and ecological) and their integration with direct/indirect economic losses, (iv) reliability analysis of flood defence systems and (v) SPR-based integrated flood risk analysis involving both tangible and intangible losses and its implementation for two selected pilot sites (representative for an open coast and an urban estuarine area in Germany). The key results are briefly summarised and the lessons learned for future flood risk studies are finally drawn. Keywords integrated risk analysis, SPR-Concept, extreme storm surge, flood defense structures and systems, reliability analysis, dike breach modelling, intangible and tangible flood losses, GIS-based spatial modelling Zusammenfassung Das Verbundprojekt XtremRisk wird zunächst kurz beschrieben. Schwerpunkte des Forschungsvorhabens waren die Entwicklung, Verbesserung und Erweiterung von Grundlagen, Methoden und Modellen hinsichtlich folgender Aspekte: (i) Physikalisch mögliche extreme Sturmfluten für verschiedene heutige und künftige Klimaszenarien, (ii) Versagensformen und-mechanismen von Hochwasserschutzwerken, (iii) Evaluation der intangiblen Flutschäden (soziale und Umweltschäden) sowie deren Aggregation mit direkten und indirekten Schäden in eine integrierten Risikoanalyse, (iv) Zuverlässigkeitsanalyse von Hochwasserschutzsystemen, (v) Implementierung der integrierten Risikoanalyse unter Berücksichtigung der tangiblen und intangiblen Schäden auf der Grundlage des bewährten SPR-Konzeptes (Source-Pathway-Receptor) am Bespiel von zwei ausgewählten Standorten an der deutschen Nordseeküste: Sylt repräsentativ für eine offenen Küste und Hamburg für ein urbanes Ästuar-Gebiet. Der Beitrag fokussiert lediglich auf einige Schlüsselergebnisse und die wichtigsten Lehren für künftige Forschungsvorhaben.
Das Verbundprojekt XtremRisk wird zunächst kurz beschrieben. Schwerpunkte des Forschungsvorhabens... more Das Verbundprojekt XtremRisk wird zunächst kurz beschrieben. Schwerpunkte des Forschungsvorhabens waren die Entwicklung, Verbesserung und Erweiterung von Grundlagen, Methoden und Modellen hinsichtlich folgender Aspekte: (i) Physikalisch mögliche extreme Sturmfluten für verschiedene heutige und künftige Klimaszenarien, (ii) Versagensformen und -mechanismen von Hochwasserschutzwerken, (iii) Evaluation der intangiblen Flutschäden (soziale und Umweltschäden) sowie deren Aggregation mit direkten und indirekten Schäden in eine integrierten Risikoanalyse, (iv) Zuverlässigkeitsanalyse von Hochwasserschutzsystemen, (v) Implementierung der integrierten Risikoanalyse unter Berücksichtigung der tangiblen und intangiblen Schäden auf der Grundlage des bewährten SPR-Konzeptes (Source-Pathway-Receptor) am Bespiel von zwei ausgewählten Standorten an der deutschen Nordseeküste: Sylt repräsentativ für eine offenen Küste und Hamburg für ein urbanes Ästuar-Gebiet. Der Beitrag fokussiert lediglich auf ei...
The International Journal of Ocean and Climate Systems, 2012
German coasts are often affected by extreme storm surges which have already led to major damages ... more German coasts are often affected by extreme storm surges which have already led to major damages along the coastline in the past. The joint research project “XtremRisK” was initiated with the main objective of enhancing the knowledge with respect to the uncertainties of extreme storm surge predictions as well as quantifying exemplarily the flood risk under current conditions and future climate scenarios for two pilot sites in Germany: Sylt Island representative for an open coast and Hamburg for an estuarine urban area. Flood risk is generally determined by the product of the flooding probability and the possible losses associated with the flood event. Flood losses are categorized as tangible and intangible depending on whether or not the losses can be assessed in monetary values. Up to date, intangible loses are not or only partially incorporated in flood risk analysis due to the lack of appropriate evaluation and integration methodologies. This study focuses on developing methodolo...
Coastal Engineering Journal, 2015
ABSTRACT A brief overview of the joint research project XtremRisK is given. The project has been ... more ABSTRACT A brief overview of the joint research project XtremRisK is given. The project has been focusing on developing/improving/expanding the knowledge, methods and models with respect to (i) physically possible extreme storm surge for current conditions and scenarios for climate change, (ii) failure mechanisms of flood defenses, (iii) assessment of intangible losses (social and ecological) and their integration with direct/indirect economic losses, (iv) reliability analysis of flood defense systems and (v) source–pathway–receptor (SPR)-based integrated flood risk analysis involving both tangible and intangible losses and its implementation for two selected pilot sites (representative for an open coast and an urban estuarine area in Germany). The key results are briefly summarized and the lessons learned for future flood risk studies are finally drawn.
Das Verbundprojekt XtremRisk wird zunächst kurz beschrieben. Schwerpunkte des Forschungsvorhabens... more Das Verbundprojekt XtremRisk wird zunächst kurz beschrieben. Schwerpunkte des Forschungsvorhabens waren die Entwicklung, Verbesserung und Erweiterung von Grundlagen, Methoden und Modellen hinsichtlich folgender Aspekte: (i) Physikalisch mögliche extreme Sturmfluten für verschiedene heutige und künftige Klimaszenarien, (ii) Versagensformen und-mechanismen von Hochwasserschutzwerken, (iii) Evaluation der intangiblen Flutschäden (soziale und Umweltschäden) sowie deren Aggregation mit direkten und indirekten Schäden in eine integrierten Risikoanalyse, (iv) Zuverlässigkeitsanalyse von Hochwasserschutzsystemen, (v) Implementierung der integrierten Risikoanalyse unter Berücksichtigung der tangiblen und intangiblen Schäden auf der Grundlage des bewährten SPR-Konzeptes (Source-Pathway-Receptor) am Bespiel von zwei ausgewählten Standorten an der deutschen Nordseeküste: Sylt repräsentativ für eine offenen Küste und Hamburg für ein urbanes Ästuar-Gebiet. Der Beitrag fokussiert lediglich auf einige Schlüsselergebnisse und die wichtigsten Lehren für künftige Forschungsvorhaben.
Flood risk is generally defined as the product of the flooding probability and the possible losse... more Flood risk is generally defined as the product of the flooding probability and the possible losses associated with the flood event. Flood losses are categorized as tangible and intangible depending on whether or not the losses can be assessed in monetary values. Up to date, intangible loses are not or only partially incorporated in flood risk analysis due to the lack of appropriate methodologies for their evaluation and integration with tangible losses in the overall risk analysis. Therefore, within this research study, methodologies for the evaluation of intangible losses due to flooding and their integration with tangible economic losses in risk analysis were developed .This paper focuses on the integration methodology which was developed within the framework of a GIS based multi-criteria analysis, including the results of a spatial analysis which was exemplarily performed for the different flood losses and integrated losses for a selected pilot site in Hamburg, Germany.
Coastal Engineering Proceedings, 2020
Flood risk is generally defined as the combination of the probability of a flood event and the po... more Flood risk is generally defined as the combination of the probability of a flood event and the potential losses. Flood losses might be divided in two categories, namely tangible and intangible. Tangible losses are evaluated in monetary values and hence commonly incorporated in flood risk analysis. Intangible losses, especially environmental losses, are mostly not incorporated in flood risk analysis due to the lack of appropriate and generally accepted evaluation methods. This research focuses on the development of a new approach to evaluate environmental losses due to coastal floods.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/xyiwlw3jkYo
Storm surges in the North Sea have caused massive floods in Germany and are expected to occur mor... more Storm surges in the North Sea have caused massive floods in Germany and are expected to occur more frequently due to climate change. The German XtremRisK project was started with the main objective to determine flood risks in estuarine areas and at open coasts in Hamburg and Sylt Island, due to extreme storm events in the North Sea. The risk is estimated using the definition ‘product of probability and the expected damages’ (Oumeraci, 2004). The expected damages are either tangible, generally evaluated in monetary terms (Smith and Ward, 1998; Jonkman and Vrijling, 2008) or intangible. Evaluation of intangible damages such as health impacts, cultural and environmental damages in monetary terms is extremely difficult (e.g. Tapsell et al., 2002; Messner et al., 2006), but cannot be omitted when calculating the overall risk. Therefore, the main focus of this research is to determine the applicability of available valuation methodologies to evaluate intangible damages induced by floods i...
Research for Policy and Practice, 2012
Research for Policy and Practice, 2012
Coastal Engineering Journal, 2015
Coastal Engineering Proceedings, 2012
The joint research project "XtremRisK" was initiated with the main objective of enhancing the kno... more The joint research project "XtremRisK" was initiated with the main objective of enhancing the knowledge with respect to the uncertainties of extreme storm surge predictions as well as quantifying exemplarily the flood risk under current conditions and future climate scenarios exemplarily for two pilot sites in Germany: Sylt Island representative for an open coast and Hamburg for an estuarine urban area. Flood risk is generally determined by the product of the flooding probability and the possible losses associated with the flood event. Flood losses are categorized as tangible and intangible depending on whether or not the losses can be assessed in monetary values. Up to date, intangible loses are not or only partially incorporated in flood risk analysis due to the lack of appropriate evaluation and integration methodologies. This study focuses on developing methodologies for the evaluation of intangible losses due to flooding and for their integration with tangible losses in flood risk analysis
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Papers by Dilani Dassanayake