Estimation of Terrestrial Water Storage Variations in Sichuan-Yunnan Region from GPS Observations Using Independent Component Analysis

Bin Liu,Cuilin Kuang,Wujiao Dai,Wenkun Yu,Xuemin Xing

doi:10.3390/rs14020282

Bin Liu, Cuilin Kuang + Show 3 more

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https://doi.org/10.3390/rs14020282

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Abstract

GPS can be used to measure land motions induced by mass loading variations on the Earth’s surface. This paper presents an independent component analysis (ICA)-based inversion method that uses vertical GPS coordinate time series to estimate the change of terrestrial water storage (TWS) in the Sichuan-Yunnan region in China. The ICA method was applied to extract the hydrological deformation signals from the vertical coordinate time series of GPS stations in the Sichuan-Yunnan region from the Crustal Movement Observation Network of China (CMONC). These vertical deformation signals were then inverted to TWS variations. Comparative experiments were conducted based on Gravity Recovery and Climate Experiment (GRACE) data and a hydrological model for validation. The results demonstrate that the TWS changes estimated from GPS(ICA) deformations are highly correlated with the water variations derived from the GRACE data and hydrological model in Sichuan-Yunnan region. The TWS variations are overestimated by the vertical GPS observations the northwestern Sichuan-Yunnan region. The anomalies are likely caused by inaccurate atmospheric loading correction models or residual tropospheric errors in the region with high topographic variability and can be reduced by ICA preprocessing.

Highlights

Terrestrial water storage (TWS) variations play an important role in the study of the global water cycle and water resource management [1,2]
There is no significant difference between TWS
Considering the fact that northSichuan-Yunnan is near the Qinghai-Tibet Plateau and the terrain is extremely complex western Sichuan-Yunnan is near the Qinghai-Tibet Plateau and the terrain is extremely (Figure 1), the inaccurate atmospheric loading (ATML) correction in this area may be the cause of anomalies in complex (Figure 1), the inaccurate ATML correction in this area may be the cause of anomthe GPS inversion result

Summary

Introduction

Terrestrial water storage (TWS) variations play an important role in the study of the global water cycle and water resource management [1,2]. Gravity Recovery and Climate Experiment (GRACE) data have been widely used to measure the variations of large-scale water storage [3,4,5]. GRACE-derived TWS values have low spatial resolution (300–500 km) and low temporal resolution (monthly). Another popular method is the use of hydrological assimilation models, such as Global. Land Data Assimilation Systems (GLDAS) [6], to understand the water cycle process and effect of land surface processes on climate [5]. GLDAS models neglect either reservoir water or groundwater and lack comprehensive in-situ measurements

Results

Discussion

Conclusion