Insights into water mass change in the Yangtze River Basin from the spectral integration of GNSS and GRACE observations
Abstract
We develop a joint inversion method in the spectral domain that accounts for different signal characteristics in Global Navigation Satellite System (GNSS) and Gravity Recovery and Climate Experiment (GRACE) observations for quantifying terrestrial water storage (TWS) changes in the Yangtze River Basin (YRB). The method seamlessly integrates these geodetic datasets with distinct spatial scales and coverages. We exploit the Slepian basis functions, being spectrally band-limited and spatially concentrated, to put these datasets together in the regional TWS modeling. Our integrated geodetic results reveal variable spatiotemporal patterns of water storage changes within the YRB, hydrological extremes, and their linkage to interannual climate variability. The results indicate that annual precipitation in the middle and lower YRB is twice of that in the Jinsha River Basin (the uppermost basin of YRB), yet the TWS change is less than a half. This large discrepancy in the ratio of water storage and precipitation can be attributed to substantial runoff in the middle and lower YRB. The joint geodetic inversion identifies extreme droughts and flood events in the basin, consistent with the assessments from precipitation anomalies and Global Flood Awareness System. We also find that interannual TWS variations in the Jinsha River Basin are modulated by Indian Ocean Dipole, while those in the upper YRB and middle and lower YRB are modulated by El Niño-Southern Oscillation. Our findings highlight the potential use of geodetic data combination to advance hydrological variabilities in the region and inform water resource management strategies in response to climate change.
- Publication:
-
Earth and Planetary Science Letters
- Pub Date:
- October 2024
- DOI:
- Bibcode:
- 2024E&PSL.64418929T
- Keywords:
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- GNSS;
- GRACE;
- Terrestrial water storage changes;
- Spectral domain;
- Hydrological extremes