Characteristics Analysis And Multi-Model Coupling Prediction Of Mine Discharge In Hebi Mining Area

Hebi mining area is located in the alluvial and diluvial plain in front of Taihang Mountain in the north of Henan Province.The water resource management department requires the city’s thermal power enterprises to shut down Wells and use surface water and mine discharge.The contradiction between supply and demand of water resources affects the development of the local area.It is urgent to find out the water quality and dynamic change of mine discharge.Based on this,this paper adopts Mann-Kendall test and wavelet period analysis methods to analyze the characteristics of the mine discharge between years,trends,periods and spatial changes.Secondly,according to the characteristics contained in the discharge,the multi-model coupling method is used to predict the discharge of five pairs of mines and each mine in the future.Finally,the source of mine discharge was determined according to isotope and freon content,and the quality of mine discharge was evaluated by single factor pollution index method,Nemero pollution index method and fuzzy comprehensive evaluation method.The results show that:With the continuous closure of each mine,the total discharge of the mine continues to decrease,maintaining at about 1600 m~3/h in recent years,with obvious seasonal regularity.At present,the discharge of the five pairs of mines in production has a downward trend on the whole,with a total variation of 200 m~3/h.The year 2003 was the abrupt moment of mine discharge,which changed from stable fluctuation to significant decline.In the aspect of periodic change,the variation of 12～24 months is mainly caused by the fluctuation of annual precipitation,and the variation of 48～92 months and 100～128months is related to compound factors such as raw coal output and water control methods.Due to the differences of hydrogeological conditions and mining stages,mine discharge in No.4,No.8 and No.9 mines is more,while that in No.3 and No.6 mines is less.The seasonal adjustment and HP filtering method were used to decompose the mine discharge,and the prediction model of mine discharge was established by coupling ARIMA model,trigonometric function fitting and BP neural network.Five pairs of mines and each mine are forecasted,and the results show that the average annual discharge in2021 and 2022 will be 1549.47 m~3/h and 1542.58 m~3/h respectively,and the seasonal variation is 104.14m~3/h and 155.68 m~3/h,respectively.The mine discharge of each mine will fluctuate in the future,but keep stable basically.The prediction results can provide theoretical basis for mine discharge resource utilization.The Ordovician limestone karst water and mine discharge in Hebi mining area originated from the recharge of modern atmospheric precipitation.In mine discharge,the contents of total hardness,soluble total solids,sulfate and iron exceed the standard.When the mine discharge is used for industrial water,the water quality grade of No.4 mine is good,the water quality of No.8 mine and No.9 mine is poor.When used for farmland irrigation water,the water quality of each mine is better;Mine discharge isⅤgrade water,poor water quality,after conventional treatment,can meet the requirements of thermal power enterprises and farmland irrigation water.There are 31 figures,28 tables and 85 references.