Prediction Of Water Quality Safety Of Karst Drinking Water Sources In Yangquan Based On Improved BP Neural Network

There are abundant karst water resources in our country.The karst water has an important influence on the people's survival and production,and it plays a very important role in the development and stability of the society.Niang Zi Guan water resources system is not only the largest water resource system in Yangquan,but also one of the largest karst springs in northern China.With the large-scale and large area mining of various water resources,the change of hydrodynamic conditions in spring area,the change of water chemical composition and the deterioration of water quality,it is necessary to analyze and study the chemical characteristics of karst water and water in Yangquan and the safety of water quality,which is of great significance for the protection and rational exploitation and utilization of karst groundwater in Yangquan in the future.Based on the comprehensive analysis of the hydrogeological and geological conditions in Yangquan,this paper studies the characteristics and causes of karst groundwater in Yangquan by descriptive statistical analysis,TDS and the distribution regularity of the total hardness,the subdivision rule of the conventional groundwater group,the analysis of the cause and the cause analysis,and the Pearson correlation analysis.An improved BP neuralnetwork model,such as information index evaluation and BP neural network,is applied to predict the water quality and safety of drinking water sources.The results show :(1)The spatial distribution of TDS value,total hardness,Ca2+,Mg2+,SO42-concentration is very similar,in the recharge area from north to South: the most north is the lowest,the recharge area from the north to the south is stable on a larger value,the concentration of the runoff area is the largest,the concentration in the discharge area is lower,but it is lower than the part of the recharge area and the runoff area.The spatial distribution of K+,Na+ and Cl-is similar.The concentration in the supply area in the north is low and the recharge area from the middle to the south is increased.The concentration near the runoff area is higher.In the runoff area,the content of each index increases nearly one step,which is basically the highest in the other areas,and the concentration of K+,Na+ and Cl-is the highest in this area compared with that of the other area;the discharge area is more than the recharge area.The index concentration in the runoff area decreased.The type of Hydrochemistry in the detention area is SO4·HCO3-Ca?Mg and SO4?HCO3-Ca type,and the supply area in the north is HCO3-Ca·Mg or HCO3?SO4-Ca type to the middle part.(2)The analysis of the causes of hydrochemical characteristics.Pearson correlation analysis shows that the most direct reason for the high hardness and high TDS of Niang Zi Guan water resources system is the increase of SO42-concentration.After the exploitation of coal and gypsum in the central area,the SO42-concentration will increase,and the p H value of water will decrease,which will increase the index of recharge area and runoff area.(3)Water quality safety evaluation and prediction for karst groundwater source area.The quality of karst groundwater in Yangquan is good,basically in the safety level.The improved BP model can be used for water quality index with high accuracy and objectivity and fast.It is practical for predicting the water quality of drinking water sources.(4)Based on the above water chemistry and water quality safety analysis,suggestions for the protection of karst water in Niang Zi Guan water resources system of Yangquan city are put forward.Through targeted protection of surface water,underground water,Niang Zi Guan spring water and increasing treatment facilities to eliminate pollution sources.