Darren Lumbroso

A comparative analysis of the loss of life during two recent floods in France: the sea surge caused by the storm Xynthia and the flash flood in Var

This paper aims to analyse and compare the loss of life that occurred during two recent floods in France. The first flood was due to a sea surge triggered by the storm called Xynthia that hit the Atlantic coast on 28 February 2010 (41 flood-related deaths). The second was a flash flood that struck the Var Department in the French Mediterranean region on 15 June 2010 (26 fatalities). After detailing the assumptions and expected outcomes of the study of disaster-related fatalities, the paper focuses on the characteristics of the victims and the circumstances of their deaths. In the first case, 71% of the victims were people aged over 60 (mainly women) who were surprised while they were sleeping and who died in or near their homes. In the case of the flash flood, the profiles of the victims were diverse as the flooding occurred in the afternoon and many people were trapped in open. The paper also highlights the factors that explain mortality. Physical factors such as water depth were determined. The relationship between the water depth and the age of victims was found to be relevant. In the case of the storm surge Xynthia, the correlation between age and water depth is positive. For the flash flood, the correlation between age and water depth was negative as male adults died in open. In the first case, the vulnerability of people was closely linked to human features such as type of housing and age that people are not directly responsible for. During flash floods, dangerous behaviour by people highlighted the role of risk-taking in loss of life. We also examined the particular case of the deaths of the children. The paper concludes by discussing the factors of vulnerability on frail population such as elderly people or marginalized. The lack of risk awareness and crisis preparedness were clearly a major factor of vulnerability.

Stakeholders’ perceptions of the overall effectiveness of early warning systems and risk assessments for weather-related hazards in Africa, the Caribbean and South Asia

Low-income countries are significantly more vulnerable than high-income countries to the risks posed by natural hazards. This paper describes the findings of research into stakeholders’ perceptions of the overall effectiveness of early warnings and risk assessments for weather-related hazards (i.e. cyclones, floods, droughts and landslides), for humanitarian and development purposes in low-income countries in Africa, the Caribbean and South Asia. New findings are derived from a survey and consultations with some 400 practitioners, scientists, researchers and decision-makers in the regions. Our findings, which were based upon the collated results of a literature review, stakeholder interviews together with other reviews and surveys, show that although there would appear to have been some progress in improving early warning and risk assessments for weather-related hazards, it is highly variable across the three regions. The findings are inconsistent with the self-reporting of progress against the Hyogo Framework for Action, which in many cases give a more positive view of their status. Significantly, more work is required to produce robust, reliable and accessible information to reduce vulnerability and manage risks, and this should concentrate on understanding aspects of vulnerability, effective risk communication and community-level actions, as well as some well-focused improvements in technical, and underpinning scientific aspects of early warning systems and risk assessments.

Use of an agent-based model and Monte Carlo analysis to estimate the effectiveness of emergency management interventions to reduce loss of life during extreme floods

This paper describes the use of an agent-based model, known as the Life Safety Model (LSM) and a Monte Carlo analysis to assess the effectiveness of emergency management interventions in terms of loss of life, taking into account uncertainties in the physical characteristics of the population at risk, represented by people’s height and mass. The work considered Canvey Island as a case study, which is located in the Thames Estuary. The average ground level of the island is 1 m below the mean high tide level. Canvey Island is protected against inundation by a series of flood defences. In 1953, the island was inundated by the Great North Sea Flood that breached the defences and led to the deaths of 58 people. A number of emergency management interventions (e.g. safe havens, flood warnings) were considered to ascertain if the loss of life in 1953 could have been reduced. The LSM was found to be an effective tool to compare different emergency management measures in order to ensure that loss of life is minimised when an extreme flood event occurs.

Flood Risk Management in the United Kingdom

London and the Thames Estuary’s floodplain in the southeast of England are susceptible to flooding from storm surges. They are protected from floods with a return period of up to 1000 years by the Thames Barrier and a series of flood defences. Owing to climate change the Thames Barrier and its associated defences will need to be upgraded to maintain the same level of protection. The cost and irreversibility of the potential investments means that the investments in future flood defence infrastructure are sensitive to climate change and that the potential for maladaptation is significant. In 2002, the Environment Agency, the organization responsible for flood risk management in England, established the Thames Estuary 2100 (TE2100) project with the objective of developing a strategic flood risk management plan for London and the Thames estuary through to the end of the century. The approach to flood risk management presented in the TE2100 plan included a method of developing options together with a regular updating process in which options and decisions are reviewed taking account of changing circumstances. TE2100 was the first major flood risk project in the United Kingdom to have put climate change adaptation at its core. There is scope for the adaptation pathways methodology utilized in the TE2100 to be used by planners in other situations where a lack of information creates uncertainties.