Assessing climate change impacts on flooding risks in the Belgian coastal zone

Within the scope of the Belgian project CLIMAR an attempt is made to develop an evaluation framework for adaptation scenario’s as a response to the climate change induced impacts in the North Sea area. Primary effects are direct consequences of climate change such as sea level rise, erosion, changes in temperature and precipitation and increased storminess. Secondary impacts are direct and indirect results of the primary effects on different sectors. A first phase of the project consists of identifying and scoping the secondary impacts on ecological and social-economic activities. In this paper results will be presented regarding the secondary impacts of flooding only.Climate change induced primary effects such as sea level rise and increased storminess lead to higher risks of flooding of low-lying coastal areas. One of the most significant social secondary effects is the number of people at risk due to flooding. An important economical effect of climate change is the amount of damage costs. Besides direct damages there will also be indirect economic results such as temporary suspension of production and loss of jobs. Other ecological effects of increased flooding risks are the loss of beach and dune area, as well as associated specific habitats such as wetlands. Indirectly this leads to loss of biodiversity.The magnitude of the most significant secondary effects is quantified by carrying out risk calculations. For each of the sets of the changing physical parameters a related storm scenario is statistically determined. In a first approach, the flooding risks during an extreme storm under present climate conditions and sea level rise are estimated. By means of a set of numerical models the areas susceptible to flooding in the Belgian coastal plain are identified. The resulting flooding risk maps are then used to estimate the scope of the secondary impacts