In 1993 and 1995 the Meuse overflowed its banks, leading to extensive flood damage in the Netherlands. Due to climate and land use change, the frequency of high-flows is expected to increase in the future. Furthermore, the potential damage of floods is expected to increase due to socioeconomic developments in flood-prone areas. Both of these factors can be assessed through the concept of flood risk (defined as probability of flooding x damage). In Europe, the flood risk management approach has been given added impetus by the European Flood Directive of 2007. However, there is currently a lack of knowledge internationally on the sensitivity of flood risk to long-term changes in physical and socioeconomic parameters.
Climate change is expected to increase the severity, duration and frequency of weather related extreme events, threatening water availability and food security for millions of poor people. It is clear that adaptation strategies have to be implemented from the level of farmers to communities to national governments.
ADAPTS aims to increase developing countries' adaptive capacities by achieving the inclusion of climate change and adaptation considerations in water policies, local planning and investment decisions. This will be achieved by supporting local practical initiatives in climate proofing, influencing regional water management and if feasible in up scaling the activity to other regions.
Contact information: Dr Ralph Lasage
More information: www.adaptation.nl
More information: poster presentation, Brochure
Traditionally, flood management has focused on providing protection against floods up to a given return-period, but recently there has been a shift towards a more risk based approach, whereby flood risk is defined as the probability of flooding multiplied by the consequences. However, both the probability of flooding and the consequences are expected to change in the future as a result of changes in climate and socioeconomic factors.
To date, there is relatively little known internationally about how these will influence flood risk. Most studies examining this issue have considered a limited number of discrete climate change scenarios, representing single future pathways. One of the reasons that only a limited number of climate change scenarios are used in flood risk assessment is the large amount of computational time required to convert discharge into inundation maps using hydraulic models. Moreover, for the same reason, flood risk is usually estimated based on the damage resulting from a very limited number of flood return-periods (for example European states are only obliged to map flood extents for three return-periods).
The vulnerability of densely populated areas, such as Flanders, to natural disasters – enhanced by climate change – is partly due to decades of spatial planning policies that have failed to take into account risks in land use zoning and in decisions on spatial development. Quite typical and striking example in Flanders of this lacking providence in policies is the almost yearly inundation of houses in residential zones, developed in the past or more recently in river beds.
While uncertainty remains on the exact impacts of climate change, this apparently unstoppable evolution has the potential to be so significant that it will challenge all our basic assumptions on the way our land should be used over the medium and long term. Abstraction of the success of mitigating short term measures, climate change will in any way influence the way in which Flemish society organises its use of land and space. Historically grown spatial patterns, that often are products of centuries of physical and/or societal evolution, will be affected.
Cost assessments of damages of natural hazards supply crucial information to policy development in the fields of natural hazard management and adaptation planning to climate change. There exists significant diversity in methodological approaches and terminology in cost assessments of different natural hazards and in different impacted sectors.
ConHaz provides insight into cost assessment methods, which is needed for an integrated planning and overall budgeting, and to prioritise policies. To strengthen the role of cost assessments in natural hazard management and adaptation planning, existing approaches and best practices as well as knowledge gaps are identified. ConHaz has three key objectives.
This project has studied the impact of anthropogenic climate change on the occurrence of losses from extreme weather, and financial arrangements (including insurance) to deal with these losses. The project consisted of four activities: analysis of current financial arrangements; assessment of extreme weather risks; potential of new arrangements; and stakeholder involvement.
An overview has been made of financial arrangements for extreme weather risks in The Netherlands. Especially changes in extreme rainfall and flooding hold severe risks for the national insurance sector. Flood risk transfer mechanisms in Europe have been analysed, and some aspects of private insurance arrangements may hold benefits for reducing flood risks. A global trend of increasing economic losses from weather extremes is occurring because of increases in exposure, related to growth in population and wealth. Future climate change is expected to lead to increasing losses as well. By 2050 hailstorm damages to the agricultural sector could increase by between 25% and more than 200%. A case study along the river Meuse shows that expected losses from river flooding could increase by between 96 and 719%, due to a combination of climate and socioeconomic change. The expected potential number of fatalities from flooding in the west of The Netherlands could quadruple by 2040.
NWO VENI research project, Netherlands Organisation for Scientific Research
Project leader: Dr Philip Ward
The negative socioeconomic impacts of riverine flooding (e.g. economic damage, fatalities) are huge, as exemplified by recent floods in Pakistan, Thailand, and Australia. Over 95% of damage caused by flooding is due to inland floods.
Although flood impacts are felt at the local- to regional-scale, global-scale research is also vital: development agencies must know the potential magnitude and geographical distribution of consequences in order to estimate adaptation costs, and to prioritise management in worst-affected regions. Existing research focuses on the role of long-term climate change; the role of climate variability is less understood. Climate variability refers to natural temporal fluctuations around average climate, e.g. El Niño. In other sectors, research shows that variability is as important for policy and practice as long-term change. Past research by Ward et al. (2010) showed that El Niño significantly influences flood hazard worldwide.
This project addresses two knowledge-gaps: global-scale flood impacts; and the influence of climate variability on these. A risk-hazard framework will be used, whereby risk is the product of: hazard, exposure, and vulnerability.
Jakarta has a long history of flooding. In recent decades, rapid urbanisation, land use change, land subsidence, and the clogging of the city’s waterways with garbage and sediments have intensified this problem. Future climate change will further increase the chance of flooding.
Flood risk and climate adaptation
Traditional flood management in Jakarta has mainly focused on reducing the chance of flooding. However, there is a growing recognition of the need for a more integrated flood risk approach, whereby risk is the combination of both the probability of flooding and the consequences (e.g. economic damage and loss of life). Whilst climate change clearly brings new threats to Jakarta, and other delta cities, it also provides an opportunity to plan adaptation measures that reduce flood risk both today and in the future. However, there is lack of scientific knowledge and tools on the impacts of adaptation on flood risk.
The overall project deals with the prediction of the effects of climate change in peat meadows and shallow lakes. The information generated is to be used to define and evaluate adaptation strategies. This part of the project intends to develop approaches to match the complex information generated by the project with the objectives of the stakeholders. Both the effects and the adaptation strategies have a clear spatial, temporal and uncertainty dimension. The complexity and amount of information to be processed makes it necessary to develop techniques to structure and present the information in such a way that it can be managed by the stakeholders.
Within this project we will describe the relevant decision processes and try to identify the information needs by the various stakeholders at different stages of these processes. We will develop interactive workshops to facilitate problem analysis, problem identification, design of management alternatives evaluation of alternatives and feedback to design. The project will focus on the development of spatial design approaches using a mixture of formal design routines, visualization techniques and structured feedback from participants in workshops. Techniques will be integrated in a spatial decision support framework implemented in hardware suitable for interactive use in a workshop.
Contact information: Dr Ron Janssen
An article in Science by Jeroen Aerts, Wouter Botzen, Hans de Moel and colleagues of partner institutions MIT, Princeton University and The Wharton School, presents a comprehensive cost-benefit analysis of flood risk management strategies in New York City (NYC).
To help inform policy decisions, this article applies a multidisciplinary scientific approach for an economic evaluation of flood management strategies for NYC to reduce flood risks, now and in the future. It applies a probabilistic risk assessment of hurricanes and storm surge to determine the vulnerability of exposed buildings and infrastructure for each of the 1.2 million buildings in NYC. The method is novel, since it also accounts for many sources of uncertainty. A cost-benefit analysis of flood risk-management strategies was conducted to evaluate the benefits (avoided risk) of a variety of building codes and flood protection strategies and their costs, under future scenarios of climate change and socio-economic development. In addition, the optimal timing of investments in storm-surge flood-risk protection was evaluated.
EU action on climate change is now focused on accelerating mitigation efforts, while seeking to reduce risks associated with climate change impacts. To achieve the multiple goals of cutting greenhouse gas emissions, reducing vulnerability to climate impacts, and building mitigative and adaptive capacities, climate action needs to be mainstreamed across all EU policy sectors. As the scale of European policy grows, mitigation and adaptation need increasingly to be integrated. These policies have strong international dimensions.
The project RESPONSES addresses EU policy challenges by:
- developing new global low emissions scenarios, placing EU efforts in a global context;
- building an approach for assessing EU policies against mitigation and adaptation objectives and for developing alternative policy options;
- applying this framework in five EU policy sectors (water and agriculture, biodiversity, regional development/infrastructure, health and energy), linked by a set of cross-sectoral integrative activities;
- synthesizing the results to new policy strategies.
The main outputs of the project will be:
- A set of global low emission scenarios, differentiated by key countries;
- Options and strategies for integrating mitigation and resilience to climate impacts into EU policies;
- A validated strategic climate assessment approach.
More information: Website Responses
STREAM is a raster based hydrological rainfall-runoff model, based on the Thorntwaite-Mather (1957) approach. STREAM is a transparent model, which is easy to set up, run and modify. It only requires input data on precipitation, temperature, elevation, soil (water holding capacity) and land cover as inputs (Aerts et al., 1999). STREAM is currently scripted as a Matlab© script, which can be downloaded and used for free, making use of the Topotoolbox (Schwanghart and Kuhn, 2010) for its routing. Please acknowledge these sources when using STREAM. Using STREAM requires some basic GIS skills to prepare input maps, as well as some experience with Matlab© to run the script.
Because of its flexibility, it can be set up quickly for any size catchment, given that the right input data is available. Currently it has been used from global scale to medium/small sized catchments. It has been used many times in places where there is no detailed information available, relying on publicly available global datasets for its input.
Over half of the global population live in urban areas and this is predicted to rise. Many urban areas are vulnerable to gradual environmental change and many city dwellers are concerned with the impacts of rapid or unregulated land use change, environmental health and human well-being. This is further exacerbated within city communities especially those that are socio-economically disadvantaged. Urban planners, managers and designers face demands from communities and individuals for more inclusivity in planning adaptive strategies.
Thus, the key challenge in European cities is to devise holistic transition strategies that are tailored to the needs of all stakeholders; strategies that are flexible, adaptive and applicable across urban regions and scales. These are the challenges that are being addressed by the TURAS Project. TURAS will demonstrate to city communities, businesses, planners, policy-makers and managers mechanisms for transition that may be created and implemented as we strive to move to more sustainable urban living.
Ho Chi Minh City in Vietnam faces many challenges with regard to adapting to a changing climate. This densely populated delta city is already frequently flooded due to heavy rainfall and its low position in the Delta. Problems and risks for the inhabitants are likely to increase due to sea level rise and higher river discharges. At the same time the population and economy of Ho Chi Minh City are growing rapidly. The city is expanding, also towards the sea.
The VCAPS project aims to develop an adaptation strategy for Ho Chi Minh City jointly with Vietnamese stakeholders. IVM focuses on assessing changes in flood risk under the expected changes and on developing and evaluating adaptation strategies.
Contact information: Dr Ralph Lasage
More information: www.vcaps.org