Mining Geohazards at the Perimeter of the Amyntaio Open Pit Coal Mine, West Macedonia, Greece

Land subsidence phenomena affecting the plain area surrounding the open pit as well as large landslides affecting the open cast slopes are listed among the mining induced catastrophic geo-hazards affecting the perimeter of mines. These large scale geo-hazards are related to both hydro-geological and geotechnical parameters and they cause unrevoked damage. In the present study the investigated site is the area extending at the perimeter of the Amyntaio opencast coal mine at Florina Prefecture, Northern Greece. The overexploitation of the aquifers for the dewatering of the slopes turned the mine to a large diameter well. The surface deformations caused by the land subsidence phenomenon extends 1-3 km around the mine affecting Anargiroi and Valtonera villages. Furthermore, on June 10th, 2017, a massive landslide, of approximately 80 million cubic meters, occurred at the working slopes of the mine, burrying 25 million tons of lignite, resulting in severe damage to large number of mining equipment and causing the evacuation of the nearby Anargyroi village. Apart from presenting the two catastrophic events, the current research aimed to correlate the geological, hydrogeological and geotechnical factors affecting both phenomena and outlining their mechanisms.