Recently, associate researcher Feng Wei and professor Zhong Min from the “Satellite Geodesy and Global Change” research team and the Innovative Team of “New Theory and New Technologies of Geodesy and Probing” of Institute of Geodesy and Geophysics, Chinese Academy of Sciences(IGG,CAS), and prof. Shen Si Jun from the Ohio State University, jointly with prof. Pan Yun from Capital Normal University made progress in the space and time variations of China's groundwater depletion by GRACE.
In the relatively dry northern regions of China, groundwater has become an important source of water and an important strategic resource for economic and social stability. Through joint analysis of satellite gravity, groundwater models, and groundwater observations, researchers have 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 has been a significant long-term loss of groundwater in the North China Plain over the past decade. The loss rate 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 the northwestern part of 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 10 years, indicating that there may still be long-term loss of groundwater in the area.
The relevant research results were summarized in the paper titled: “Groundwater Storage Changes in China from Satellite Gravity: An Overview”, which published in the internationally renowned academic journal 《Remote Sensing》. The research work was supported by the National Natural Science Foundation of China and the China Academy of Sciences’ strategic pilot technology project.