Chemical Characteristics and Variations of Groundwater Quality in Songnen Basin

Songnen basin is located in the center of the northeast China. It is one of the main large-scale groundwater basin which is very abundant in groundwater resources in China, but the situation of groundwater there is complex: the original groundwater quality is not very good and the pollution due to human activities is relatively severe. Based on groundwater quality data monitored by water conservancy and geological department for many years, in-depth study on the formation mechanics and regional distribution laws of primary harmful components and man-made pollutant in groundwater is conducted. Furthermore, the perennial change laws of groundwater quality in the basin because of human activities are analyzed in the paper. The results show that the primary harmful components would be concentrated under the following conditions: the geological structure is enclosed, the environment of strong reducing/alkalescent/full of organic matter in groundwater and groundwater seepage velocity is slow. The main reason for change tendency of groundwater quality is the human activities in recent years. The paper gives some advice on amelioration and preservation of groundwater quality such as enhancing regional groundwater circulation and exchange function, fighting against environment pollution, treating or refreshing the polluted well and utilizing artificial recharge with clean water of Songhua River.