An analysis of terrestrial water storage variations from GRACE and GLDAS: The Tianshan Mountains and its adjacent areas, central Asia

The development of the social economy can benefit from the study of terrestrial water storage changes on a regional scale. To analyze water recycling and climate change, variable gravity field spherical harmonic coefficients data from GRACE (Gravity Recovery and Climate Experiment) were used to compute the terrestrial equivalent water height and then compared with data from GLDAS (Global Land Data Assimilation System) terrestrial hydrological assimilation. The data were taken from 11 years of monthly scaled measurements during the time period from January 2003 to March 2013. The investigation of the interannual and seasonal terrestrial water storage changes at the Tianshan Mountains and the surrounding areas revealed the conclusions: (1) Interannual variability, accompanied by interannual and seasonal fluctuations in terrestrial water storage, showed a decreasing trend throughout the research period, with an average reduction rate 0.42 +/- 0.12 cm per year and with a minimal value occurred in 2009. (2) The seasonal maximum of terrestrial water storage occurred in spring (March to May), and the monthly maximum (22 mm) in April; the seasonal minimum of terrestrial water storage occurred in autumn (September to November), and the monthly minimum (-23 mm) occurred in October. (3) Spatially, terrestrial water storage increased in the western portion of the study area, and decreased in the eastern and middle portions. (4) In comparing the two types of data, we see that terrestrial water storage inverted by GRACE and GLDAS shows good consistency with significant liner relations, and that the peak value of terrestrial water storage calculated by GLDAS appeared about 131 days earlier than GRACE. (C) 2014 Elsevier Ltd and INQUA. All rights reserved.