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| Titel |
Terrestrial Water Storage Variations in the Heihe River Basin Recovered by GRACE Time-Variable Earth Gravity Field |
| VerfasserIn |
Z. C. Luo, Q. Li, H. H. Wang, M. S. Liao |
| Konferenz |
EGU General Assembly 2009
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250029685
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| Zusammenfassung |
| Abstract: Heihe River is a larger inland river in the Northwestern China across
the three provinces of Qinghai, Gansu and Inner Mongolia, located in the Hexi
Corridor and the middle of the Qilian Mountains, from eastern longitude of 97Ë 37’
to 102Ë 06’ and from northern latitude 37Ë 44’ to 42Ë 40’. The terrain there is
complex and the water storage variation display strongly seasonal and regional
features due to the precipitation difference of time and spatial distribution. It is of
important significance for the ecological environment and economic construction
by investigating the terrestrial water storage variations in the Heihe River basin.
48 monthly GRACE (Gravity Recovery and Climate Experiment) Earth’s gravity
field models for the period from January 2004 until December 2007 are used in the
paper, from which the tidal effects, including oceanic tide, solid Earth tide and solid
Earth pole tides are removed, as well as the non-tidal effects of atmospheric and
oceanic contributions. During data processing, the GRACE Earth’s gravity field
models are truncated to complete degree and order 60, and the time series C20 are
replaced by those obtained from analyzing SLR (Satellite Laser Ranging) data.
Using the Gaussian filtering method with smoothing radius 700km, the terrestrial
water storage variations in the Heihe River basin are recovered from the spherical
harmonic coefficients of the monthly GRACE Earth’s gravity field models, and then the
characteristics of the terrestrial water storage changes are analyzed. The results show
that the seasonal and annual feature of the terrestrial water storage variations is
revealed in the Heihe River basin. The annual variations amplitude is approximately
1.6cm in terms of equivalent water height, and achieves the maximum in April and
August each year. The similarities are shown well by comparing the terrestrial water
storage variations recovered from GRACE temporal gravity field to those from CPC
(Climate Prediction Center) hydrological model. Both of them reveal the obviously
seasonal characteristics of the terrestrial water storage variations, and the amplitude
difference is less than 0.5cm. The groundwater storage variation are obtained by
combining the terrestrial water storage variation recovered from GRACE with the
changes in solid moister and snow water equivalent calculated from GLDAS (Global
Land Data Assimilation System) hydrological model. It is concluded that GRACE
time variable gravity field can reveal the variations of the terrestrial water storage
more or less in Heihe River basin in the spatial scale, and the seasonal and annual
changes obviously in the time scale. The terrestrial water storage variations recovered
from GRACE temporal gravity field still have valuable applications in smaller river
basin.
Key words: Heihe River basin; GRACE; time-variable Earth’s gravity field; terrestrial
water
Acknowledgements: This research was jointly supported by the National 973 Program of
China (Project No.2007CB714405), the National Natural Science Foundation of China
(No.40874002), and the New Century Excellent Talents Plan of Ministry of Education, China
(NCET-07-0635). |
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