Water yield analysis of underground drainage boreholes on the basis of logarithmic normal distribution

In order to analyze the distribution rule of water flow from underground drainage borehole in coal mines, histogram, Q-Q chart and nonparametric tests were used to test the logarithmic normal distribution model for water flow from underground drainage borehole in typical working face, and the nonlinear regression model was fitted. Combined with hydrogeological conditions, the parameters in the model were analyzed. The result shows that water flow from underground drainage boreholes in working face obeys the lognormal distritution. The logarithmic mean and standard deviation of water flow from drainage borehole of typical working face have a positive linear dependence relation with mean and standard deviation of aquifer specific field of the corresponding coal field. The skewness and kurkosis of distribution curve are mainly controlled by the water abundence and its degree of uniformity of the roof quifer. The water flow from drainage borehole of adjacend multi-working faces also obeys the lognormal distribution. The research results will provide reference for the design of drainage borehole and drainage system.