GRACE-Based Terrestrial Water Storage in Northwest China: Changes and Causes

Abstract

Monitoring variations in terrestrial water storage (TWS) is of great significance for the management of water resources. However, it remains a challenge to continuously monitor TWS variations using in situ observations and hydrological models because of a limited number of gauge stations and the complicated spatial distribution characteristics of TWS. In contrast, the Gravity Recovery and Climate Experiment (GRACE) could overcome the aforementioned restrictions, providing a new reliable means of observing TWS variation. Thus, GRACE was employed to investigate TWS variations in Northwest China (NWC) between April 2002 and March 2016. Unlike previous studies, we focused on the interactions of multiple climatic and vegetational factors, and their combined effects on TWS variation. In addition, we also analyzed the relationship between TWS variations and socioeconomic water consumption. The results indicated that (i) TWS had obvious seasonal variations in NWC, and showed significant decreasing trends in most parts of NWC at the 95% confidence level; (ii) decreasing sunshine duration and wind speed resulted in an increase in TWS in Qinghai province, whereas the increasing air temperature, ameliorative vegetational coverage, and excessive groundwater withdrawal jointly led to a decrease in TWS in the other provinces of NWC; (iii) TWS variations in NWC had a good correlation with water storage variations in cascade reservoirs of the upper Yellow River; and (iv) the overall interactions between multiple climatic and vegetational factors were obvious, and the strong effects of some climatic and vegetational factors could mask the weak influences of other factors in TWS variations in NWC. Hence, it is necessary to focus on the interactions of multiple factors and their combined effects on TWS variations when exploring the causes of TWS variations.

Spatio‐temporal variation of near‐surface soil water content in China from 1988 to 2016

“…The SWC was found to increase in Northwest China (Figure 5a). This is consistent with the study by Xie et al (2018), who found that the long-term variation trends of SWC were generally characterized by increasing in arid region of China, for example Northwest. However, precipitation in Northwest China showed no significant trend (Figure 5b).…”

“…In addition, the simulated soil water data had large systematic bias, which was elevated in the west by the complex topography and increasing land heterogeneity (Chen, Fan, et al, 2017; Chen, Zhang, et al, 2017). Most other studies were concerned with the spatio‐temporal variations of satellite derived‐soil water in some specific regions of China, for example Loess Plateau (Feng et al., 2017), Qing‐Tibet Plateau (Fan et al, 2018), Northwest China (Xie et al., 2018), Eastern China (Chen et al., 2016) and so on. As a country with large area, spatio‐temporal variations of soil water in different natural divisions have not been systematically compared and the main driving forces of soil water variations in different divisions have not been determined.…”

“…(2016) found that the ration of precipitation to potential evapotranspiration is the dominant factor in determining the temporal trends of soil moisture change in eastern China. However, the interactions of climatic and vegetation factors were significant, and strong effects of some factors could weaken the influences of other factors on soil moisture change in Northwest China (Xie et al., 2018). Overall, the control mechanism of the SWC at the regional scale and in the whole China is not well understood and deserves further investigation.…”

Quantifying Vertical Deformation in the Tigris–Euphrates Basin Due to the Groundwater Abstraction: Insights from GRACE and Sentinel-1 Satellites

“…The extracted significant periodic signal is represented by the cone of influence (COI), where the phase discontinuity drops by e −2 at the boundary of the COI. The CWT is used to define the relationship between different geophysical processes-for example, the Baltic maximum sea ice extent and Arctic Oscillation index [14], land subsidence and GWS volume change [31], and climate, vegetation factors, and ∆TWS [32]. We employed the CWT to expand the groundwater volume changes and vertical displacements with corresponding time into a time-frequency space.…”

Erratum: Xie, Y.Y.; et al. GRACE-Based Terrestrial Water Storage in Northwest China: Changes and Causes. Remote Sens. 2018, 10, 1163

“…The authors wish to make a correction to their paper [1]. After the final proofreading, they realized that the affiliation was incorrect due to their carelessness.…”