Recently, associate researcher FENG Wei and Prof. ZHONG Min from the Institute of Geodesy and Geophysics (IGG) of the Chinese Academy of Sciences, Prof. SHEN Sijun from the Ohio State University, and Prof. PAN Yun from Capital Normal University made progress in the space and time variations of China's groundwater depletion through the Gravity Recovery and Climate Experiment (GRACE) data.  

In the relatively dry northern regions of China, groundwater is an important source of water and strategic resource for economic and social stability. Through joint analysis of satellite gravity, groundwater models, and groundwater observations, researchers quantitatively revealed the temporal and spatial variation of groundwater reserves in China.

The research shows that due to long-term climate drought and human over-exploitation of groundwater, there is a significant long-term loss of groundwater in the North China Plain over the past decade. The loss since 2002 is about 6 to 8 billion tons per year.

The groundwater reserves in Northeast China have significant interannual variations. In the Liaohe River Basin, groundwater is rapidly depleted from 2005 to 2009, and the average annual groundwater loss is about 5 billion tons. However, the underground aquifer has been fully replenished and the groundwater level has rebounded since 2010 due to the high rainfall.

In the Tarim Basin in Northwest China, there is still considerable uncertainty in the results of groundwater changes monitored by satellite gravity due to the influence of the Tianshan Glacier and Qinghai-Tibet plateau material change signals. However, the water level of some wells in the area has continued to decrease over the past decade, indicating that there may still be long-term loss of groundwater in the area. 

The study entitled "Groundwater Storage Changes in China from Satellite Gravity: An Overview" was published in Remote Sensing.

The research was supported by the National Natural Science Foundation of China and the Chinese Academy of Sciences. 

The time series of groundwater reserves variation in the main aquifer in the plain area of China. (Image by IGG)