Investigation on the evolution trends and influencing factors of groundwater resources in China

Groundwater resources have experienced significant changes in China in the past few decades. It is of significance to fully understand of the evolution trends and influencing factors of groundwater resources for groundwater management. Based on the data from National Water Resources Survey and China Water Resources Bulletin, the evolution trends and affecting factors of groundwater resources over past 60 years were investigated intensively. The results show that the quantity of groundwater resources has not changed a lot at the national level, but changes do occur in different areas in China; for instance, the groundwater resources of Haihe River basin, Liaohe River basin and Yellow River basin have dramatically shrunk. The recharge of groundwater has been increasingly influenced by human activities and artificial recharge has formed an important source for groundwater. More and more groundwater is discharged through human extraction while the discharge to river and evaporation from phreatic water decline. Additionally, the discharge of groundwater has already exceeded the recharge in Haihe River basin, Songhuajiang River basin, Yellow River basin and Northwest River basin, causing the imbalance of groundwater budget and overexploitation within these areas. Changes in precipitation, land surface conditions, and human activities were found as the main affecting factors for the evolution trends of groundwater resources.