Post mining hazard assessment in North Rhine-Westphalia (Germany) at the example of the Aachen hard coal mining district

In North Rhine-Westphalia, large areas are affected by mining legacies endangering the ground surface and public safety. The problems arising and the current risk management are demonstrated at the example of the Aachen hard coal mining district. Hazards especially result from outcrops of coal seams mined at shallow depths and shafts whilst galleries usually seem to be rather unperilous due to their depth and small dimension. In this paper, the design of hazard zones and the assignment of hazard classes are described. Recent scientific developments related to the size of hazard areas are described and an outlook on future procedures is given. (authors)