K Maeghe

A risk based approach to the development of evacuation plans in the mine subsidence area along the Meuse

The “Mijnverzakkingsgebied) (mine subsidence area) is located in the eastern part of Belgium along the River Meuse and is affected by subsidence up to seven meters due to historical mining activities. The subsidence is so large that during high flood stages in the river Meuse the area is under severe risk of flooding if one of the surrounding dikes would break. In such a case water depth in the area could locally reach 7 meters. This would lead to great damage to the houses and economic activities in the region. To minimize the victims and damage in the event of a dike failure, different evacuation plans were set up, which were based on two-dimensional inundation maps of the study area. These flooding scenarios were simulated assuming dike breaches at various locations. Applications of calibrated one-dimensional and two-dimensional hydraulic models of the river Meuse and the mine subsidence area enabled analyzing maximum water depth, the time-to-flooding and local water depth fluctuations during an inundation. Both applied hydraulic models were fed with recent and accurate bathymetry and topographical data from a detailed DEM monitored via laserscanning. The input data was of high quality which enabled one to carry out the analysis on a resolution of 25 meters. A combination of the different inundation maps and the local streetmaps gives an insight into the optimal evacuation direction for the inhabitants of the different villages. The different scenarios show also that certain regions can be flooded with inundation depths of more than 5 meters. In these regions, people have to be evacuated immediately by helicopter.