Study On The Response Of Mine Water Inflow To Precipitation In Pingdingshan No.7 Mine

There has been a long process of the hydrological study in human history.Along with the expansion of human activities and the improvement of science and technology,the new content about hydrological has been increasing.In recent years,the relationship between the deep mine water,surface water and groundwater has been a new hot issue during hydrology research.Based on this,this paper adopts the elastic coefficient method and grey theory model to analyze the relationship between precipitation and mine water inflow quantitatively.The purpose of this paper is to study water resources transformation relationship between precipitation and groundwater in coal mining area scientifically,which can provide scientific basis for the development of water resources and the prevention of groundwater in the coal mine exploration area.The grey theory model studies the statistical regularity in different scale by changing the scales of time sequence,which can provide an effective prediction method in the study of the complexity of time series evolution.Through the Hurst index,the R/S analysis method can determine the status of sustainability of time sequence,which can estimate of the length of the time sequence memory to the initial value by average cycle length.This method has been applied in many fields,but it has not been seen in the study of the relationship between mine water and surface water.Mann-Kendall trend test and elastic coefficient method are widely used in the study of hydrological surface water sequence and meteorological data sequence,but they have not been used in the study of mine water inflow.According to the measured monthly and annual precipitation and mine water data from 2003 to 2014 in Pingdingshan No.7 mine,the method of non-uniform coefficient and the method of concentration factor analysis are used in this paper to analyze the variations of precipitation and mine water inflow.Then the method of Mann-Kendall trend test is adopted to analyze the characteristics of inter-annual variability of precipitation and mine water inflow.Then the elastic coefficient method is used to make quantitative analysis of the impact of the precipitation change on the change of mine water inflow,which means the elastic coefficient method is adopted to quantize the response of mine water inflow change to the change of the precipitation.Finally,the grey theory model is used to analyze and forecast the variation trend of precipitation and mine water inflow in the future,and meanwhile it can to determine their own change cycle period respectively.The results show that the distribution of precipitation has been steady gradually,and the mine water inflow tends to be uniform distribution.Annual precipitation was significantly reduced,and April 2004 is the start of the annual precipitation mutation,which is the symbol of rainfall going less.Mine water inflow was significantly reduced annually,and March 2007 is the start of the annual mine water inflow mutation,which is the symbol of mine water inflow going less.Mine water inflow process is consistent with the process of precipitation,and the precipitation change has a great impact on the mine water inflow change.The decreasing trend of mine water inflow and the reducing tendency of precipitation have the same synchronization.In other words,the trend of precipitation change is close to the mine water inflow changing characteristics.It shows that the precipitation change will have significantly influence on mine water inflow.The method of Elastic coefficient analysis shows that the precipitation decreasing by 1%will cause the mine water inflow reducing 0.94%,which means the annual rainfall reduces 14.62 mm and the mine water inflow will reduce 289.52m~3.Grey prediction model shows that the average cycle period of monthly mine water inflow sequence is 25years and the average cycle period of monthly precipitation sequence is 15 years.What is more,the two years rainfall have obviously influence on the following one year mine water inflow since 2007 in Pingdingshan No.7 mine.The prediction accuracy of GM(1,1)prediction model for the mine water inflow is 80.86%.On this basis,R/S-GM(1,1)prediction model is established by the R/S analysis,whose prediction accuracy is84.81%.This forecasting model has some advantages that the length of time series span is short,and the volatility is relatively gently.Grey prediction model opens up a new way for medium and long term prediction of mine water inflow.