Integrated Flood Risk Analysis and Management Methodologies Building a model to estimate Risk to Life for European flood events – Final Report Date November 2007 Report Number T10-07-10 Revision Number 1_6_Pn10 M10.1 Task Leader Sue Tapsell FLOODsite is co-funded by the European Community Sixth Framework Programme for European Research and Technological Development (2002-2006) FLOODsite is an Integrated Project in the Global Change and Eco-systems Sub-Priority Start date March 2004, duration 5 Years Document Dissemination Level PU Public PU PP Restricted to other programme participants (including the Commission Services) RE Restricted to a group specified by the consortium (including the Commission Services) CO Confidential, only for members of the consortium (including the Commission Services) Co-ordinator: HR Wallingford, UK Project Contract No: GOCE-CT-2004-505420 Project website: www.floodsite.net FLOODsite Project Report Contract No:GOCE-CT-2004-505420 DOCUMENT INFORMATION Title Building models to estimate risk to life for flood events Lead Author Sally Priest Theresa Wilson, Sue Tapsell, Edmund Penning-Rowsell, Christophe Contributors Viavattene, Amalia Fernandez-Bilbao Distribution Public Document Reference T10-07-10 DOCUMENT HISTORY Date Revision Prepared by Organisation Approved by Notes 07/09/07 1_0_Pn10 S. Priest, T. FHRC/MU S.Tapsell Wilson 18/09/07 1_1_Pn10 S. Tapsell FHRC/MU S.Priest 23/10/07 1_2_Pn10 S. Priest FHRC/MU S.Tapsell 30/10/07 1_3_Pn10 S. Priest FHRC/MU E.Penning- Rowsell 30/11/07 1_4_Pn10 S. Tapsell FHRC.MU 10/11/08 1_5_Pn10 S. Priest FHRC.MU 09/03/09 1_6_Pn10 S. Priest FHRC.MU Minor changes to Disclaimer ACKNOWLEDGEMENT The work described in this publication was supported by the European Community‘s Sixth Framework Programme through the grant to the budget of the Integrated Project FLOODsite, Contract GOCE-CT- 2004-505420. DISCLAIMER This document reflects only the authors‘ views and not those of the European Community. This work may rely on data from sources external to the members of the FLOODsite project Consortium. Members of the Consortium do not accept liability for loss or damage suffered by any third party as a result of errors or inaccuracies in such data. The information in this document is provided ―as is‖ and no guarantee or warranty is given that the information is fit for any particular purpose. The user thereof uses the information at its sole risk and neither the European Community nor any member of the FLOODsite Consortium is liable for any use that may be made of the information. © Members of the FLOODsite Consortium T10_07_10_Risk_to_Life_Model_V1_6_P10.doc 09/03/09 iii FLOODsite Project Report Contract No:GOCE-CT-2004-505420 SUMMARY The research carried out for Activity 1 of Task 10 focuses on developing a methodology to estimate loss of life from flood events. In order to reduce the risk to life it is necessary to understand the causes of loss of life in floods in order to pinpoint where, when and how loss of life is more likely to occur and what kind of intervention and flood risk management measures may be effective in eliminating or reducing serious injuries and fatalities. The objectives of this research were therefore: to further develop a model, or models, to provide insight into, and estimates of, the potential loss of life in floods, based on work already undertaken in the UK and new data collected on flood events in Continental Europe; to map, through the use of GIS and building partly on existing work, the outputs of the risk to life model(s) providing estimates of the potential loss of life in floods. The research took as a starting point the Risk to People model developed in the UK (HR Wallingford, 2003; 2005) and assessed the applicability of this model for flood events in Continental Europe, which tend to be more severe and life threatening. Data on flood events were gathered from 25 locations across six European countries as well as data from an additional case study in the UK. A number of problems were identified with the current model when applied to the flood data collected from Continental Europe. In particular the model was not designed for the major rivers and mountainous catchments compared with the UK and thus resulted in dramatic over-predictions of injuries and fatalities. Moreover, the model was found to contain several structural weaknesses. Research conducted into the factors surrounding European flood fatalities also highlighted the importance of institutional arrangements and mitigating factors such as evacuation and rescue operations. Finally, the UK model was seen to be hugely sensitive to people vulnerability, which in much of the wider European flooding is arguably of less importance in than it is in the UK. Thus a new semi-qualitative ‗threshold‘ model which combines hazard and exposure thresholds and mitigating factors has been developed to assess risk to life from flooding in a wider European context. The model has been designed to be flexible enough to be used and applied at a range of scales, from a broad assessment at a regional or national scale, to a more detailed local scale. This flexibility is essential as not all European countries have detailed flood data that is readily available. It is envisaged that the model should be used as a tool to allow flood managers to make general and comparative assessments of risk to life and to consider the targeting of resources before, during and after flooding. The new model also permits simple mapping of risk to life which again can be applied at various scales. Two additional reports are also related to Task 10. The first is a case study of the 2002 flooding in the Gard region of France (Lutoff and Ruin, 2007) and is based on research conducted for a PhD thesis (see Ruin 2007; T10-07-11). The second report (Tapsell et al., 2008) focuses on understanding the complex health impacts of floods and presents a conceptual model of the various factors impacting human health and well-being with respect to flooding (FLOODsite Project document T10-09-02). This research was originally intended to be a part of the work for the Risk to Life model in Activity 1, but on reflection it was decided that it should be reported separately. T10_07_10_Risk_to_Life_Model_V1_6_P10.doc 09/03/09 iv FLOODsite Project Report Contract No:GOCE-CT-2004-505420 T10_07_10_Risk_to_Life_Model_V1_6_P10.doc 09/03/09 v FLOODsite Project Report Contract No:GOCE-CT-2004-505420 CONTENTS Document Information ........................................................................................................................... iii Document History .................................................................................................................................. iii Acknowledgement .................................................................................................................................. iii Disclaimer .......................................................................................................................................... iii Summary .......................................................................................................................................... iv Contents .......................................................................................................................................... vi 1. Introduction ............................................................................................................................... 1 1.1 Background and Context ................................................................................... 1 1.2 Aims of Task 10 Activity 1: Building models to estimate loss of life and health impacts for flood events ................................................................... 1 1.2.1 European Floods Directive ................................................................................ 2 1.3 Structure of the report ....................................................................................... 2 2. Review of the Literature ........................................................................................................... 3 2.1 Sources of information ...................................................................................... 3 2.2 Floods and risk to life or injury ......................................................................... 3 2.3 Factors affecting cause of death or injury ......................................................... 5 2.3.1 Area characteristics ........................................................................................... 6 2.3.2 Flood characteristics .......................................................................................... 7 2.3.3 Dwelling characteristics .................................................................................... 7 2.3.4 Population characteristics .................................................................................. 8 2.3.5 Population behaviour ...................................................................................... 10 2.3.6 Examples of common flood scenarios in Europe ............................................ 11 2.4 Examples of methods to calculate flood risks to people ................................. 13 3. The ‘Flood risks to people’ methodology .............................................................................. 18 3.1 Flood Hazard Rating (HR) .............................................................................. 19 3.2 Area Vulnerability