Enhancing local action planning through quantitative flood risk analysis: a case study in Spain

[EN] This article presents a method to incorporate and promote quantitative risk analysis to support local action planning against flooding. The proposed approach aims to provide a framework for local flood risk analysis, combining hazard mapping with vulnerability data to quantify risk in terms of expected annual affected population, potential injuries, number of fatalities, and economic damages. Flood risk is estimated combining GIS data of loads, system response, and consequences and using event tree modelling for risk calculation. The study area is the city of Oliva, located on the eastern coast of Spain. Results from risk modelling have been used to inform local action planning and to assess the benefits of structural and non-structural risk reduction measures. Results show the potential impact on risk reduction of flood defences and improved warning communication schemes through local action planning: societal flood risk (in terms of annual expected affected population) would be reduced up to 51% by combining both structural and nonstructural measures. In addition, the effect of seasonal population variability is analysed (annual expected affected population ranges from 82 to 107 %, compared with the current situation, depending on occupancy rates in hotels and campsites). Results highlight the need for robust and standardized methods for urban flood risk analysis replicability at regional and national scale.This research was conducted within the framework of the INICIA project, funded by the Spanish Ministry of Economy and Competitiveness (BIA2013-48157-C2-1-R). The article processing charges for this open-access publication will be covered by the INICIA project. We would like to thank the city of Oliva for their willingness to share data, knowledge, and experience with the authors and for initiating this risk-informed journey.Castillo-Rodríguez, J.; Escuder Bueno, I.; Perales Momparler, S.; Porta-Sancho, J. (2016). Enhancing local action planning through quantitative flood risk analysis: a case study in Spain. Natural Hazards and Earth System Sciences. 16(7):1699-1718. https://doi.org/10.5194/nhess-16-1699-2016S16991718167Barredo, J. I.: Normalised flood losses in Europe: 1970–2006, Nat. Hazards Earth Syst. Sci., 9, 97–104, https://doi.org/10.5194/nhess-9-97-2009, 2009.Castillo-Rodriguez, J. T., Escuder-Bueno, I., Altarejos-García, L., and Serrano-Lombillo, A.: The value of integrating information from multiple hazards for flood risk analysis and management, Nat. Hazards Earth Syst. Sci., 14, 379–400, https://doi.org/10.5194/nhess-14-379-2014, 2014.DEFRA: FD2321/TR1 – The Flood Risks to People Methodology, London, available at: www.defra.gov.uk/environ/fcd/research (last access: February 2016), 2006.EC: Guide to Cost Benefit Analysis of Investment Projects: European Commission, DG for Regional and Urban Policy, Brussels BELGIUM, https://doi.org/10.2776/97516, 2008.Escuder-Bueno, I., Castillo-Rodriguez, J. T., Zechner, S., Jöbstl, C., Perales-Momparler, S., and Petaccia, G.: A quantitative flood risk analysis methodology for urban areas with integration of social research data, Nat. Hazards Earth Syst. Sci., 12, 2843–2863, https://doi.org/10.5194/nhess-12-2843-2012, 2012.European Parliament: DIRECTIVE 2007/60/EC OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL of 23 October 2007 on the assessment and management of flood risks, L 228, 27–34, 2007.Fell, R., Corominas, J., Bonnard, C., Cascini, L., Leroi, E., and Savage, W. Z.: Guidelines for landslide susceptibility, hazard and risk zoning for land use planning, Eng. Geol., 102, 85–98, https://doi.org/10.1016/j.enggeo.2008.03.022, 2008.Fuchs, S., Spachinger, K., Dorner, W., Rochman, J., and Serrhini, K.: Evaluating cartographic design in flood risk mapping, Environ. Hazards, 8, 52–70, https://doi.org/10.3763/ehaz.2009.0007, 2009.Fuchs, S., Keiler, M., and Zischg, A.: A spatiotemporal multi-hazard exposure assessment based on property data, Nat. Hazards Earth Syst. Sci., 15, 2127–2142, https://doi.org/10.5194/nhess-15-2127-2015, 2015.Gamper, C. D. and Turcanu, C.: On the governmental use of multi-criteria analysis, Ecol. Econ., 2, 298–307, https://doi.org/10.1016/j.ecolecon.2007.01.010, 2007.Generalitat Valenciana: Plan de Acción Territorial sobre prevención del Riesgo de Inundación en la Comunitat Valenciana (PATRICOVA), Valencia, 67–72, 2015.Hall, J. W., Meadowcroft, I. C., Sayers, P. B., and Bramley, M. E.: Integrated Flood Risk Management in England and Wales, 2003.Hennig, C., Dise, K., and Muller, B.: Achieiving Public Protection with Dam Safety Risk Assessment Practices, Nat. Hazards Rev., 4, 126–135, https://doi.org/10.1061/(ASCE)1527-6988(2003)4:3(126)1997, 2003.Hijós Bitrián, F., Mañueco Pfeiffer, M. G., and Segura Notario, N.: Comité nacional español de grandes presas, Congreso Nacional de Presas, Proc. of Risk-Based Decision Making in Water Resources VIII, edited by: Yacov, Y., Haimes, D., Moser, A., and Stakhiv, E. Z., 19–32, 2010.Jongman, B., Kreibich, H., Apel, H., Barredo, J. I., Bates, P. D., Feyen, L., Gericke, A., and Neal, J.: Comparative flood damage model assessment?: towards a European approach, Nat. Hazards Earth Syst. Sci., 12, 3733–3752, https://doi.org/10.5194/nhess-12-3733-2012, 2012.Jongman, B., Koks, E. E., Husby, T. G., and Ward, P. J.: Increasing flood exposure in the Netherlands: implications for risk financing, Nat. Hazards Earth Syst. Sci., 14, 1245–1255, https://doi.org/10.5194/nhess-14-1245-2014, 2014.Jonkman, S. N., Vrijling, J. K., and Vrouwenvelder, A. C. W. M.: Methods for the estimation of loss of life due to floods?: a literature review and a proposal for a new method, Nat. Hazards, 46, 353–389, https://doi.org/10.1007/s11069-008-9227-5, 2008.Klijn, F. and Schweckendiek, T.: Comprehensive Flood Risk Management: Research for Policy and Practice, CRC Press, Boca Raton, 297–330, 2012.Klijn, F., Kreibich, H., De Moel, H., and Penning-rowsell, E.: Adaptive flood risk management planning based on a comprehensive flood risk conceptualisation, Mitig. Adapt. Strat. Glob. Chang., 20, 845–864, https://doi.org/10.1007/s11027-015-9638-z, 2015.MAGRAMA: Propuesta de mínimos para la metodología de realización de los mapas de riesgo de inundación, Madrid, Ministerio de Agricultura, Alimentación y Medio Ambiente, Madrid, Spain, 2013.Marcotullio, P. J. and McGranahan, G.: Scaling Urban Environmental Challenges: From local to global and back, Earthscan with UNU-IAS and IIED, Earthscan, London, Sterling, VA, 2006.Mayors Adapt: The new integrated covenant of mayors for climate and energy, www.mayors-adapt.eu (last access: July 2016), 2015.Mazzorana, B., Comiti, F., Scherer, C., and Fuchs, S.: Developing consistent scenarios to assess fl ood hazards in mountain streams, J. Environ. Manage., 94, 112–124, https://doi.org/10.1016/j.jenvman.2011.06.030, 2012.Mazzorana, B., Comiti, F., and Fuchs, S.: A structured approach to enhance flood hazard assessment in mountain streams, Nat. Hazards, 67, 991–1009, https://doi.org/10.1007/s11069-011-9811-y, 2013.Merz, B. and Thieken, A. H.: Flood risk curves and uncertainty bounds, Natural Hazards, 51, 437–458, https://doi.org/10.1007/s11069-009-9452-6, 2009.Merz, B., Kreibich, H., Schwarze, R., and Thieken, A.: Assessment of economic flood damage, Nat. Hazards Earth Syst. Sci., 1697–1724, https://doi.org/10.5194/nhess-10-1697-2010, 2010.Meyer, V., Scheuer, S., and Haase, D.: A multicriteria approach for flood risk mapping exemplified at the Mulde river, Germany, Nat. Hazards, 48, 17–39, https://doi.org/10.1007/s11069-008-9244-4, 2009.Meyer, V., Kuhlicke, C., Luther, J., Fuchs, S., Priest, S., Dorner, W., Serrhini, K., Pardoe, J., and Mccarthy, S.: Recommendations for the user-specific enhancement of flood maps, Nat. Hazards Earth Syst. Sci., 12, 1701–1716, https://doi.org/10.5194/nhess-12-1701-2012, 2012.Miller, A., Jonkman, S. N., and Van Ledden, M.: Risk to life due to flooding in post-Katrina New Orleans, Nat. Hazards Earth Syst. Sci., 15, 59–73, https://doi.org/10.5194/nhess-15-59-2015, 2015.Morales-Torres, A., Serrano-Lombillo, A., Escuder-Bueno, I., and Altarejos-García, L.: The suitability of risk reduction indicators to inform dam safety management, Struct. Infrastruct. Eng., 12, 2479, https://doi.org/10.1080/15732479.2015.1136830, 2016.Nakicenovic, N., Lempert, R., and Janetos, A.: Special Issue of Climatic Change on the framework for the development of new socioeconomics scenarios for climate change research, Clim. Change, 122, 351–361, https://doi.org/10.1007/s10584-013-0982-2, 2013.Parker, D. J., Tunstall, S., and Wilson, T.: Socio-Economic Benefits of Flood Forecasting and Warning, in: International conference on innovation advances and implementation of flood forecasting technology, Session 8, 1–11, ACTIF, available at: http://www.actif-ec.net/conference2005/proceedings/index.html, (last access: July 2016), Tromso, Norway, 2005.Penning-Rowsell, E. C., Priest, S. J., Parker, D. J., Morris, J., Tunstall, S. M., Viavatenne, C., Chatterton, J., and D., O.: Flood and Coastal Erosion Risk Management, A manual for economic appraisal, London, Routledge, Chapter 4, 2013.Quan-Luna, B., Blahut, J., Westen, C. J. Van, Sterlacchini, S., Asch, T. W. J., and Van and Akbas, S. O.: The application of numerical debris flow modelling for the generation of physical vulnerability curves, Nat. Hazards Earth Syst. Sci., 11, 2047–2060, https://doi.org/10.5194/nhess-11-2047-2011, 2011.Ramis, C., Homar, V., Amengual, A., Romero, R., and Alonso, S.: Daily precipitation records over mainland Spain and the Balearic Islands, Nat. Hazards Earth Syst. Sci., 13, 2483–2491, https://doi.org/10.5194/nhess-13-2483-2013, 2013.Sayers, P. B., Horritt, M., Penning-Rowsell, E., and McKenzie, A.: Climate Change Risk Assessment 2017 Projections of future flood risk in the UK, London, 69–73, 2015.Serrano-Lombillo, A., Escuder-Bueno, I., De Membrillera-Ortuño, M. G., and Altarejos-García, L.: Methodology for the Calculation of Annualized Incremental Risks in Systems of Dams, Risk Anal., 31, 1000–1015, https://doi.org/10.1111/j.1539-6924.2010.01547.x, 2011.Totschnig, R. and Fuchs, S.: Mountain torrents: Quantifying vulnerability and assessing uncertainties, Eng. Geol., 155, 31–44, https://doi.org/10.1016/j.enggeo.2012.12.019, 2013.UK Health and Safety Executive: Reducing Risks: Protecting People – HSE's decision making process, Norwich, Health and Safety Executive, 40–48, 2001.Université Catholique de Louvain: EM-DAT Database: The OFDA/CRED International Disaster Database, available at: http://www.emdat.be/ (last access: 1 October 2015), 2015.USACE: Economic Guidance Memorandum (EGM) 01-03: Generic Depth-Damage Relationships, 2000.Velasco, M., Cabello, À., and Russo, B.: Flood damage assessment in urban areas, Application to the Raval district of Barcelona using synthetic depth damage curves, Urban Water J., https://doi.org/10.1080/1573062X.2014.994005, 2015.Vrijling, J. K.: Probabilistic design of water defense systems in The Netherlands, 74, 337–344, 2001.Ward, P. J., De Moel, H., and Aerts, J. C. J. H.: How are flood risk estimates affected by the choice of return-periods?, Nat. Hazards Earth Syst. Sci., 11, 3181–3195, https://doi.org/10.5194/nhess-11-3181-2011, 2011.Ward, P. J., Jongman, B., Weiland, F. S., Bouwman, A., Beek, R. Van, Bierkens, M. F. P., and Ligtvoet, W.: Assessing flood risk at the global scale: model setup, results, and sensitivity, Environ. Res. Lett., 044019, https://doi.org/10.1088/1748-9326/8/4/044019, 2013a.Ward, P. J., Jongman, B., Weiland, F. S., Bouwman, A., van Beek, R., Bierkens, M. F. P., Ligtvoet, W., and Winsemius, H. C.: Assessing flood risk at the global scale: model setup, results, and sensitivity, Environ. Res. Lett., 8, 044019, https://doi.org/10.1088/1748-9326/8/4/044019, 2013b.Winsemius, H. C., Van Beek, L. P. H., Jongman, B., Ward, P. J., and Bouwman, A.: A framework for global river flood risk assessments, Hydrol. Earth Syst. Sci., 17, 1871–1892, https://doi.org/10.5194/hess-17-1871-2013, 2013

Risk-informed local action planning against flooding: lessons learnt and way forward for a case study in Spain

After 29 years of the largest flood event in modern times (with the highest recorded rainfall rate at the Iberian Peninsula with 817 mm in 24 hours), the municipality of Oliva faces the challenge of mitigating flood risk through the development and implementation of a local action plan, in line with other existent and ongoing structural measures for flood risk reduction. Located 65 km from Valencia, on the South-Eastern coast of Spain, Oliva is affected by pluvial, river and coastal flooding and it is characterized by a complex and wide-ranging geography and high seasonal variation in population. A quantitative flood risk analysis has been performed to support the definition of flood risk management strategies. This paper shows how hazard, exposure and vulnerability analyses provide valuable information for the development of a local action plan against flooding, for example by identifying areas with highest societal and economic risk levels. It is concluded that flood risk management actions, such as flood warning and monitoring or evacuation, should not be applied homogenously at local scale, but instead actions should be adapted based on spatial clustering. Implications about the impact of education and training on flood risk reduction are also addressed and discuss

Risk-informed local action planning against flooding: lessons learnt and way forward for a case study in Spain

After 29 years of the largest flood event in modern times (with the highest recorded rainfall rate at the Iberian Peninsula with 817 mm in 24 hours), the municipality of Oliva faces the challenge of mitigating flood risk through the development and implementation of a local action plan, in line with other existent and ongoing structural measures for flood risk reduction. Located 65 km from Valencia, on the South-Eastern coast of Spain, Oliva is affected by pluvial, river and coastal flooding and it is characterized by a complex and wide-ranging geography and high seasonal variation in population. A quantitative flood risk analysis has been performed to support the definition of flood risk management strategies. This paper shows how hazard, exposure and vulnerability analyses provide valuable information for the development of a local action plan against flooding, for example by identifying areas with highest societal and economic risk levels. It is concluded that flood risk management actions, such as flood warning and monitoring or evacuation, should not be applied homogenously at local scale, but instead actions should be adapted based on spatial clustering. Implications about the impact of education and training on flood risk reduction are also addressed and discuss

Stoma-free survival after anastomotic leak following rectal cancer resection: worldwide cohort of 2470 patients

Background: The optimal treatment of anastomotic leak after rectal cancer resection is unclear. This worldwide cohort study aimed to provide an overview of four treatment strategies applied. Methods: Patients from 216 centres and 45 countries with anastomotic leak after rectal cancer resection between 2014 and 2018 were included. Treatment was categorized as salvage surgery, faecal diversion with passive or active (vacuum) drainage, and no primary/secondary faecal diversion. The primary outcome was 1-year stoma-free survival. In addition, passive and active drainage were compared using propensity score matching (2: 1). Results: Of 2470 evaluable patients, 388 (16.0 per cent) underwent salvage surgery, 1524 (62.0 per cent) passive drainage, 278 (11.0 per cent) active drainage, and 280 (11.0 per cent) had no faecal diversion. One-year stoma-free survival rates were 13.7, 48.3, 48.2, and 65.4 per cent respectively. Propensity score matching resulted in 556 patients with passive and 278 with active drainage. There was no statistically significant difference between these groups in 1-year stoma-free survival (OR 0.95, 95 per cent c.i. 0.66 to 1.33), with a risk difference of -1.1 (95 per cent c.i. -9.0 to 7.0) per cent. After active drainage, more patients required secondary salvage surgery (OR 2.32, 1.49 to 3.59), prolonged hospital admission (an additional 6 (95 per cent c.i. 2 to 10) days), and ICU admission (OR 1.41, 1.02 to 1.94). Mean duration of leak healing did not differ significantly (an additional 12 (-28 to 52) days). Conclusion: Primary salvage surgery or omission of faecal diversion likely correspond to the most severe and least severe leaks respectively. In patients with diverted leaks, stoma-free survival did not differ statistically between passive and active drainage, although the increased risk of secondary salvage surgery and ICU admission suggests residual confounding