Both safety and productivity in underground gassy coal mines can be improved substantially if an appropriate gas
management system is introduced. A strong direct relationship exists between the gas emission rate, roof and floor strata
relaxation zones characteristic, mining activities and gas drainage practices. Detailed knowledge of geological factors, gas
and coal-rock properties, as well as mining systems are necessary for the methodology used in predicting overall
underground gassiness, and planning gas capture and ventilation systems. Early gas emission calculations for various
mining activities, particularly for the longwall mining system are essential. A reasonably accurate prediction of gas make
as well as the design of ventilation, gas recovery (drainage holes) techniques can be made using 'Floorgas' and 'Roofgas'
computer simulations, provided sufficient geological, mining, and gas data are made available.