Abstract: In order to explore the influence of over-exploitation of groundwater on the hydrochemical characteristics of groundwater, we analyzed the dynamic changes of and relationship between groundwater level and water chemistry in the condition of over exploitation by comparing groundwater level and groundwater quality between 1997 and 2010. Results showed that when groundwater level declined, magnesium ion content and sulfate content increased correspondingly, indicating that spatial changes in groundwater level is highly consistent with that in chemical composition, which means that water chemistry is greatly affected by groundwater level. Spatial superposition results suggest that 72.2% of the changes in magnesium ion content coincided with groundwater level decline, and 53.1% of the changes in sulfate contentcoincided with groundwater level decline. Over exploitation affected groundwater chemistry through changing the discharge and recharge conditions as well as the water environment in saturated zone and non-saturated zone.

Key words: groundwater, over-exploitation, hydrochemical characteristics, evolution law, spatial analysis