Mining geohazards susceptibility and risk mapping: The case of the Amyntaio open-pit coal mine,West Macedonia,Greece

During the last decades, numerous methodologies for the construction of both susceptibility and risk maps have been developed in order to identify and mitigate geohazards such as landslides and secondarily land subsidence phenomena caused by the collapse of natural or man-made underground cavities. According to literature review, the conducted research concerning the assessment of land subsidence risk due to the overexploitation of the aquifer is still at an early stage. This study focuses οn the land subsidence phenomenon due to the overexploitation of the aquifer occurring in the Amyntaio basin in West Macedonia, hosting the active Amyntaio open-pit coal mine. This phenomenon has caused significant damage to settlements, farmlands and infrastructure. In order to construct susceptibility and risk maps knowledge of the geological, geotechnical, hydrogeological and tectonic settings of the study area is required. The proposed methodology for the production of a susceptibility and a risk map of land subsidence was based on the semi-quantitative method Weighted Linear Combination (WLC). The results were evaluated with an extensive field survey action recording, besides the above-mentioned settings, the spatial distribution of surface ruptures. The excellent agreement between the produced maps and the findings of the field survey, proved the added value of the maps, assigning them as crucial tools for the management of land subsidence phenomena.