Présentations Colloques

Oral Presentation
Session 7.04: Groundwater and man-made underground works
Hasan Yazicigil Hasan
Dewatering Impact Assessment of Longwall Coal Mining on Groundwater Resources in Central Turkey
A thermal power plant is being planned to be constructed at a coal basin, located in Central Anatolia. The pre-feasibility studies indicate that about 100 million tons of coal can be extracted from the site, via open cut and underground longwall mining during the mine life of 26 years. Since dry working conditions are prerequisite for a safe and operational mining, prediction of the groundwater inflow rate to the open pit and underground panels play a critical role. This study intends to determine dewatering requirements of the underground panels and evaluate anticipated impacts of dewatering on the groundwater resources. To analyze these aspects, a 3D numerical groundwater flow model of the site was constructed by using FEFLOW software. The dewatering requirements were evaluated at the three critical panel locations. In the simulations, simultaneous operation of open pit and underground panels were considered. The preliminary results indicate that groundwater inflow rate to the panels range from 167 L s to 311 L s, based on the location of the panels. The long term impacts of dewatering on groundwater resources were assessed in terms of spring discharge and base flow rates in the Kirmir Stream. As a result of dewatering, majority of village water supply springs and fountains will dry up in the area. Also, the base flow rates to the Kirmir stream will be decreased by 20 – 35 % based on the panel locations.