SpatioTemporal Variations in Groundwater Revealed by GRACE and Its Driving Factors in the HuangHuaiHai Plain, China The HuangHuaiHai (3H) Plain is the major cropproducing region in China. Due to the longterm overexploitation of groundwater for irrigation, the groundwater funnel is constantly expanding and the scarcity of water resources is prominent in this region. In this study, Gravity Recovery and Climate Experiment (GRACE) and hydrological models were used to estimate the spatialtemporal changes of groundwater storage (GWS) and the driving factors of GWS variations were discussed in the 3H Plain. The results showed that GRACEbased GWS was depleted at a rate of xe2x88x921.14 xc2xb1 0.89 cmy in the 3H Plain during 2003 to 2015. The maximum negative anomaly occurred in spring due to agricultural irrigation activities. Spatially, the loss of GWS in the Haihe River Basin is more serious than that in the Huaihe River Basin, presenting a decreasing trend from south to north. Conversely, the blue water footprint (WFblue) of wheat exhibited an increasing trend from south to north. During the drought years of 2006, 2013, and 2014, more groundwater was extracted to offset the surface water shortage, leading to an accelerated decline in GWS. This study demonstrated that GWS depletion in the 3H Plain is well explained by reduced precipitation and groundwater abstraction due to anthropogenic irrigation activities.

Greening Trends of Southern China Confirmed by GRACE As reported by the National Aeronautics and Space Administration (NASA), the world has been greening over the last two decades, with the highest greening occurring in China and India. The increasing vegetation will increase plant tissue accumulation and water storage capacity, and all of these variations will cause mass change. In this study, we found that the mass change related to greening in Southern China could be confirmed by Gravity Recovery and Climate Experiment (GRACE) observations. The mean mass change rate detected by GRACE is 6.7 xc2xb1 0.8 mmyr in equivalent water height during 2003xe2x80x932016 in our study region. This is consistent with the sum of vegetation tissue, soil water and groundwater change calculated using multisource data. The vegetation accumulation is approximately 3.8 xc2xb1 1.3 mmyr, which is the major contribution to region mass change. We also found that the change of water storage capacity related to vegetation can be detected by GRACE.