文摘
Examination and rehabilitation of mining legacies often result initially in separate risk management systems for surface openings and near-surface mining activities. On the one hand this can be explained by more or less spectacular past loss events around abandoned surface openings and on the other hand by the gradual change of approach to and perception of the issue of abandoned near-surface mines in the last centuries respectively, that has taken place lately. Initially, the focus used to rest on the entrances as they present a high but spatially limited risk potential and, being technical underground structures that break through the surface, they are also easier to detect and prioritise than near-surface mining or other mine workings. Against this background, this risk assessment, prioritisation and rehabilitation limited purely to the surface openings does make sense for large deep mining shafts. For smaller surface openings like, for example sloping shafts which were mostly driven in the seam, however, it is imperative to evaluate the risk in dependence on the associated seam as well as the near-surface mining operations which took place therein. For this reason, with respect to the risk management of abandoned near-surface mines, it is essential to take a holistic approach to analysis and evaluation but above all concerning implementation planning and rehabilitation of mine workings and affected areas respectively. On the one hand it comprises all facts to be collected beforehand and the possibly resulting reciprocal effects, however, on the other hand, influences resulting from exploratory or rehabilitation measures themselves are also of importance. Any intervention in the underground has the potential to at least upset the temporary balance and can for this reason actively change the risk potential.