Water inflows prediction technique of water inflow from roof aquifer during extraction of shallow seam

Aming at the problems such as low prediction accuracy, vague time-spacial concept and bad guidance to actual production of prediction of water inflows from roof of mining face, the paper, from the time-cpatial variation of coal extraction and the evoluation of groundwater flow, analysed theoreticaly the major problems of analytic method represented mainly by big-well method and gallery method to predict water inflow from the floor of working face, put forward that during extraction of shallow seam the water recharge in roof aquifer was composed of the released volume of pulsatile-typed static water storage and gradualy increased dynamic water racharge, gave thetime-spatial dynamic prediction method of dradualy increased mine water inflow during extraction, not only the amplitude of the water inflow in whole mine, but also the time variation process and the characteristics of spatial distribution of water inflow. It improved greatly the accuracy of prediction results and the actual guiding significance for production. In combination with the mining plan and the subsequent production plan, it intruduced the concept of newly increased water yield, interferential water yield and residual water yield, calculated and predicted the water inflow and ist dynamic variation process in a mine during 2011 to 2015.