Hydrological variability and loading deformation in the Yangtze river basin based on modern geodetic means

Abstract

The complex process of water storage change in the Yangtze River Basin (YRB) includes strong feedbacks and connections with global climate change. This study adopted Global Positioning System (GPS) observations and Gravity Recovery and Climate Experiment (GRACE) and Follow-On (FO) data from 2002 to 2021, along with Global Land Data Assimilation System (GLDAS) model outputs and Satellite Altimetry data, to analyse changes in hydrological mass in the YRB. Singular Spectrum Analysis (SSA) was used fill the missing data of GRACE/GRACE-FO from 2017 to 2018. GRACE/GRACE-FO and GLDAS derived terrestrial water storage (TWS) show different spatial distributions in the different river sections of YRB, and the long-term positive trend is due to increased mass, mainly in the late upstream and middle-lower reaches. Principal component analysis (PCA) was used to separate the common-mode components (CMC) in the YRB’s continuous GPS network, and it was found several of these periodic oscillation signals are connected to hydrology. In addition, it was discovered that changes in hydrological mass in the YRB are influenced by precipitation and temperature and TWS anomalies may be associated with El Niño/Southern Oscillation (ENSO) events. These findings increase our understanding of the complex climate and dynamic hydrological processes of YRB.

Keywords

• Yangtze river basin
• GPS
• GRACE/GRACE-FO and GLDAS
• satellite altimetry data
• water storage anomalies
• interannual fluctuations of hydrology