Study On The Interrelation Between Groundwater Chemical Field And Dynamic Field In Dawu Water Source Area Of Zibo

Zibo City is one of the important industrial cities in Shandong Province.There are many petrochemical enterprises in the area.As one of the main water supply sources in Zibo,Dawu Water Source Area is the main source of domestic and industrial water supply in Zhangdan District and Linzi District.Since the water source began to be used,the maximum exploitation amount has reached 520,000 m_per day.With the rapid development of local economy,the characteristics of groundwater in Dawu water source area have attracted wide attention.Based on the project of "Three-dimensional Visualization Information System Construction of Dawu Water Source Area in Zibo City",the dynamic characteristics of groundwater dynamic field and hydrochemical field in Dawu Water Source Area are studied by analyzing the groundwater level dynamics and the changes of chemical components in Dawu Hydrogeological Unit from 1980 to 2017,and then the relationship between groundwater level and chemical components is studied by means of grey correlation analysis.Dawu water source is located in the northern discharge area of Dawu hydrogeological unit,which is the key research area of this paper.The results show that the limestone mountain area in the south of Dawu Hydrogeological Unit is significantly affected by meteorological precipitation,and the groundwater level decreases more significantly than that in the northern plain.The groundwater dynamics in the northern plain area is more obviously affected by human activities.The dynamic state of karst water level in water source area is influenced by both artificial exploitation and atmospheric precipitation.The fluctuation of water level has the characteristics of steep rise and slow fall.The water level in May-June is low,and the water level in September-October is high.It shows the characteristics of precipitation recharge and human exploitation.Secondly,the chemical type of groundwater in water source areas for many years has gradually changed from bicarbonate sulfuric acid water to chlorine bicarbonate sulfate water.The content of Clin groundwater has been increasing,and TDS,SO42-,K++Na+,NO3-have an upward trend.At present,among all the inorganic chemical components tested,TDS,NO3-and total iron exceed the standard of drinking water significantly.In addition,most of the organic contents in groundwater in source areas experienced a trend of first increasing and then decreasing.Halogenated hydrocarbons exceeded the standard limit of drinking water in 2017,followed by monocyclic aromatic hydrocarbons.Their distribution characteristics are closely related to the distribution of local enterprises and residential areas.According to the characteristics of annual variation,the content of chemical components in groundwater in flood season is higher than that in dry season,especially the content of organic pollutants increases significantly in flood season,which indicates that the pollution source of groundwater is mainly located in surface aeration zone rather than aquifer,and that atmospheric precipitation infiltrates into groundwater while recharging groundwater,it also brings pollutants into aquifer.Finally,the content of chemical components in groundwater is correlated with groundwater level.The groundwater level decreases,TDS increases,pH decreases,and the content of oil in groundwater decreases.