Time evolution of groundwater quality in Dehui City

The unreasonable development and utilization of groundwater in Dehui City, China, has resulted in poor groundwater quality conditions. Based on the collection of a large amount of groundwater chemical data and hydrogeological data collected by Dehui City from 1992 to 2015, this paper uses hydrogeological analysis, graphic and other methods and ArcGIS toolbox to analyze the groundwater quality of this City. The study shows that the concentration of groundwater chemical components in the vicinity of the Songhua River is decreasing with time, and the concentration of groundwater chemical components in other regions is increasing with time. The increase of chemical concentrations are affected by human activities and water-rock interaction. The decrease of groundwater chemical concentration in Songhua River area is caused by the mixing between dilute river water and groundwater.