Evaluation methods of flood risk models in the (re)insurance industry

France experiences catastrophic floods on a yearly basis, with significant societal impacts. In this paper, we critically evaluate the French Flood Risk Governance (FRG) system with the aim of identifying any shortcoming and, thereby, to suggest improvements. To do so, we employ a historical assessment of catastrophic past flood events in the Provence-Alpes-C&#244;te d'Azur (PACA) region and perform Strengths-Weaknesses-Opportunities-Threats (SWOT)-analysis. Our evaluation shows that despite persistent government efforts, the impacts of flood events in the region do not appear to have lessened over time. Identical losses in the same locations (e.g. Riou de l&#8217;Argenti&#232;re watershed) can be observed after repetitive catastrophic events (e.g. 2015, 2019) triggering local inhabitant protests. We argue that the French FRG system can benefit from the following improvements: a) regular updates of the risk prevention plans and tools; b) the adoption of a Build Back Better logic instead of promoting the reconstruction of damaged elements in the same locations; c) taking into account undeclared damages into flood risk models (and not only those declared to flood insurance); d) increased communication between the actors of the different steps of each cycle (prepare, control, organise etc.); e) increased communication between three main elements of the cycle (risk prevention, emergency management and disaster recovery); f) an approach that extends the risk analysis outside the borders of the drainage basin (to be used in combination with the current basin risk models); and g) increased participation in FRG from local population. We also briefly discuss the use operational research methods for the optimisation of the French FRG.

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Flood forecasting using a coupled hydrological and hydraulic model (based on FVM) and highresolution meteorological model

E3S Web of Conferences ◽

10.1051/e3sconf/20184006028 ◽

2018 ◽

Vol 40 ◽

pp. 06028 ◽

Cited By ~ 8

Author(s):

Marcos Sanz-Ramos ◽

Arnau Amengual ◽

Ernest Bladé ◽

Romu Romero ◽

Hélène Roux

Keyword(s):

Flood Risk ◽

Overland Flow ◽

Extreme Rainfall ◽

Flood Forecasting ◽

Water Levels ◽

Flood Risk Assessment ◽

Flood Events ◽

Risk Models ◽

Meteorological Model ◽

Risk Assessment And Management

A forecasting systems based on the coupling of meteorological, hydrologic, hydraulic and risk models is used to minimize the risks associated to water scarcity and flooding. The fulfilment of such complex forecasting chains can allow obtaining information of the most plausible scenarios of water and risk management up to 96 hours ahead. In the present work, flood forecasting was carried out for different events in the upper La Muga basin (including the reservoir), within the European project “Flood Risk Assessment and Management in the Pyrenees” (http://pgriepm. eu/). The main purpose of the project was to develop a method to optimize the management of flood scenarios in order to minimize the flood risk while maximizing the water resources. The good fit of all the models, obtaining the forecasting rainfall and converting the overland flow in water levels in the reservoir, can give tools and important information to the authorities or dam managers for suitable management during the extreme rainfall and flood events.

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Pluvial flood catastrophe modelling: a trans-disciplinary approach.

10.5194/egusphere-egu2020-1333 ◽

2020 ◽

Author(s):

Konstantinos Karagiorgos ◽

Daniel Knos ◽

Jan Haas ◽

Sven Halldin ◽

Barbara Blumenthal ◽

...

Keyword(s):

Risk Management ◽

Flood Risk ◽

Urban Areas ◽

Insurance Industry ◽

Integrated Approach ◽

Effective Prevention ◽

The Public ◽

Modelling Framework ◽

Catastrophe Modelling ◽

The Impact

Pluvial floods are one of the most significant natural hazards in Europe causing severe damage to urban areas. Following the projected increase in extreme precipitation and the ongoing urbanization, these events play an important role in the ongoing flood risk management discussion and provoke serious risk to the public as well as to the insurance sector. However, this type of flood, remains a poorly documented phenomenon. To address this gap, Swedish Pluvial Modelling Analysis and Safety Handling (SPLASH) project aims to develop new methods and types of data that improve the possibility to value flood risk in Swedish municipalities by collaboration between different disciplines.SPLASH project allows to investigating the impact of heavy precipitation along the entire risk modelling chain, ultimate needed for effective prevention. This study presents a pluvial flood catastrophe modelling framework to identify and assess hazard, exposure and vulnerability in urban context. An integrated approach is adopted by incorporating &#8216;rainfall-damage&#8217; patterns, flood inundation modelling, vulnerability tools and risk management. The project is developed in the &#8216;OASIS Loss Modelling Framework&#8217; platform, jointly with end-users from the public sector and the insurance industry.The Swedish case study indicates that the framework presented can be considered as an important decision making tool, by establishing an area for collaboration between academia; insurance businesses and rescue services, to reduce long-term disaster risk in Sweden.

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Flood recurrence under climate change: a probabilistic flood risk assessment of critical infrastructure in the Danube basin

10.5194/egusphere-egu2020-18439 ◽

2020 ◽

Author(s):

Michel Wortmann ◽

Kai Schröter

Keyword(s):

Flood Risk ◽

Climate Model ◽

Critical Infrastructure ◽

Insurance Industry ◽

Danube River ◽

Detailed Model ◽

Flood Level ◽

Basin Scale ◽

The Future ◽

The Impact

Consistent information on fluvial flood risks in large river basins is typically sparse. This is especially true for the Danube River basin covering up to 14 countries and creating a patchwork of flood risk information across a populous and flood-prone region. As climatic changes have shown to increase flooding in the future, consistent basin-scale assessments prove vital to the insurance industry as well as municipal and infrastructural planning. The Future Danube Model (FDM) was designed to fill this gap complying to both insurance industry and climate science standards. That is, allowing for a reasonably detailed model scale (based on a 25m digital elevation model), stochastic sampling to create a large number of extreme events and flood event footprints (10k years), a thorough calibration and validation as well as the use of an ensemble of climate model output to drive the model under scenario conditions. The model is here used to assess the impact on critical infrastructure across the basin. Results indicate a marked increase in flood risk has already occurred when comparing the current climate period (2006-2035) to the reference period (1970-1999). Further increases are projected under a moderate and a business as usual scenario for the next climate period (2020-2049) and the end of the century (2070-2099). In large parts of the basin, the historical 100-year flood level, often used as a critical protection level for infrastructure, is projected to be equalled or exceeded every 50&#8211;10 years, while areas with a 100-year flood risk are projected to increase by 6-19%.

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Limits to natural disasters management: the influence of human behavior

10.5194/egusphere-egu2020-5551 ◽

2020 ◽

Author(s):

Jeroen Aerts

Keyword(s):

Climate Change ◽

Risk Assessment ◽

Risk Management ◽

Natural Disasters ◽

Human Behavior ◽

Flood Risk ◽

Behavioral Adaptation ◽

Risk Models ◽

Physically Based ◽

The Impact

Despite billions of dollars of investments in disaster risk reduction (DRR), data over the period 1994- 2013 show natural disasters caused 1.35 million lives. Science respond with more timely and accurate information on the dynamics of risk and vulnerability of natural hazards, such as floods. This information is essential for designing and implementing effective climate change adaptation and DRR policies. However, how much do we really know about how the main agents in DRR (individuals, businesses, government, NGO) use this data? How do agents behave before, during, and after a disaster, since this can dramatically affect the impact and recovery time. Since existing risk assessment methods rarely include this critical &#8216;behavioral adaptation&#8217; factor, significant progress has been made in the scientific community to address human adaptation activities (development of flood protection, reservoir operations, land management practices) in physically based risk models.This presentation gives an historic overview of the most important developments in DRR science for flood risk. Traditional risk methods integrate vulnerability and adaptation using a &#8216;top- down&#8217; scenario approach, where climate change, socio economic trends and adaptation are treated as external forcing to a physically based risk model (e.g. hydrological or storm surge model). Vulnerability research has made significant steps in identifying the relevant vulnerability indicators, but has not yet provided the necessary tools to dynamically integrate vulnerability in flood risk models.However, recent research show novel methods to integrate human adaptive behavior with flood risk models. By integrating behavioral adaptation dynamics in Agent Based Risk Models, may lead to a more realistic characterization of the risks and improved assessment of the effectiveness of risk management strategies and investments. With these improved methods, it is also shown that in the coming decades, human behavior is an important driver to flood risk projections as compared to other drivers, such as climate change. This presentation shows how these recent innovations for flood risk assessment provides novel insight for flood risk management policies.

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Assessing the global risk of climate change to re/insurers using catastrophe models and hazard maps

10.5194/egusphere-egu2020-5323 ◽

2020 ◽

Author(s):

Sarah Jones ◽

Emma Raven ◽

Jane Toothill

Keyword(s):

Climate Change ◽

Sea Level ◽

Flood Risk ◽

River Flow ◽

Climate Model ◽

Flood Hazard ◽

Insurance Industry ◽

Global Climate Model ◽

Hazard Maps ◽

The Impact

In 2018 worldwide natural catastrophe losses were estimated at around USD $155 billion, resulting in the fourth-highest insurance payout on sigma records, and in 2020 JBA Risk Management (JBA) estimate 2 billion people will be at risk to inland flooding. By 2100, under a 1.5&#176;C warming scenario, the cost of coastal flooding alone as a result of sea level rise could reach USD $10.2 trillion per year, assuming no further adaptation. It is therefore imperative to understand the impact climate change may have on global flood risk and insured losses in the future.The re/insurance industry has an important role to play in providing financial resilience in a changing climate. Although integrating climate science into financial business remains in its infancy, modelling companies like JBA are increasingly developing new data and services to help assess the potential impact of climate change on insurance exposure.We will discuss several approaches to incorporating climate change projections with flood risk data using examples from research collaborations and commercial projects. Our case studies will include: (1) building a national-scale climate change flood model through the application of projected changes in river flow, rainfall and sea level to the stochastic event set in the model, and (2) using Global Climate Model data to adjust hydrological inputs driving 2D hydraulic models to develop climate change flood hazard maps.These tools provide outputs to meet different needs, and results may sometimes invoke further questions. For example: how can an extreme climate scenario produce lower flood risk than a conservative one? Why may adjacent postcodes' flood risk differ? We will explore the challenges associated with interpreting these results and the potential implications for the re/insurance industry.

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Review Article: Validation of flood risk models: current practice and innovations

10.5194/nhess-2017-303 ◽

2017 ◽

Cited By ~ 2

Author(s):

Daniela Molinari ◽

Karin De Bruijn ◽

Jessica Castillo ◽

Giuseppe T. Aronica ◽

Laurens M. Bouwer

Keyword(s):

Flood Risk ◽

Flood Hazard ◽

Flood Damage ◽

Quality Data ◽

Risk Models ◽

Risk Modelling ◽

Risk Estimates ◽

Models Validation ◽

Benchmark Solutions ◽

Research Recommendations

Abstract. Although often neglected, model validation is a key topic in flood risk analysis, as flood risk estimates are characterised by significant levels of uncertainty. In this paper, we discuss the state of art of flood risk models validation, as concluded from the discussion among more than 50 experts at two main scientific events. The events aimed at identifying policy and research recommendations towards promoting more common practice of validation, and an improvement of flood risk models reliability. We pay specific attention to the different components of the risk modelling chain (i.e. flood hazard, defence failure and flood damage analysis) as well as to their role into risk estimates, to highlight specificities and commonalities with respect to implemented techniques and research needs. The main conclusions from this review can be summarised as the need of higher quality data to perform validation and of benchmark solutions to be followed in different contexts, along with a greater involvement of end-users in the debate on flood risk models validation.

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