Where to build altimetry-based stage-discharge rating curves? Insights from Sentinel-3
River discharge is one of the most important hydrological quantities that provides freshwater for human use and ecosystems. Ground-based measurements of discharge are often expensive, and for many rivers globally, discharge data may exist but are not publicly available for various reasons. Therefore...
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| Main Authors: | , |
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| Format: | Article |
| Language: | English |
| Published: |
Taylor & Francis Group
2025-12-01
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| Series: | GIScience & Remote Sensing |
| Subjects: | |
| Online Access: | https://www.tandfonline.com/doi/10.1080/15481603.2025.2530802 |
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| Summary: | River discharge is one of the most important hydrological quantities that provides freshwater for human use and ecosystems. Ground-based measurements of discharge are often expensive, and for many rivers globally, discharge data may exist but are not publicly available for various reasons. Therefore, spaceborne measurements have been pursued as alternatives. Satellite radar altimetry is an extremely valuable source of information for estimating river discharge. While numerous case studies exist, the question of which locations are preferable to build altimetry-based stage-discharge rating curves remains less studied. The goal of this study was to investigate this issue by constructing a large set of stage-discharge rating curves across the globe. We derived the water levels of global rivers wider than 300 m based on the Sentinel-3 altimeters. Based on historical discharge records and altimetry-derived water levels, 737 rating curves were constructed using a Bayesian hierarchical approach. The results indicate a median Kling-Gupta Efficiency (KGE) of 0.76 and a normalized root-mean-squared error (NRMSE) of 33.8%, demonstrating the reliability of this method. Notably, water level variability and width-to-depth ratio emerged as key factors influencing rating curve accuracy, suggesting that prioritizing river segments with significant water level fluctuations can enhance the precision of discharge estimation. These findings provide valuable guidance for selecting satellite tracks to augment global river discharge monitoring networks. The reliable rating curves could also facilitate near real-time forecasting of river discharge. |
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| ISSN: | 1548-1603 1943-7226 |