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The measurement of river discharge is necessary for understanding many water‐related issues. Traditionally, river discharge is estimated by measuring water stage and converting the measurement to discharge by using a stage–discharge rating curve. Our proposed method for the first time couples the measurement of water‐surface width with river width–stage and stage–discharge rating curves by using very high‐resolution satellite data. We used it to estimate the discharge in the Yangtze (Changjiang) River as a case study. The discharges estimated at four stations from five QuickBird‐2 images matched the ground observation data very well, demonstrating that the proposed approach can be regarded as ancillary to traditional field measurement methods or other remote methods to estimate river discharge. Copyright © 2004 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

In order to determine material fluxes in rivers by non‐contact methods, it is essential to estimate river discharge first. Although developed and optimized for open oceans, satellite radar altimetry has the potential to monitor variations in the levels of inland waters such as lakes and rivers. Making use of the concept of an ‘assumed reference point’, we converted TOPEX/Poseidon satellite altimetry data on water level variations in the Yangtze River (Changjiang) to ‘water level’ data. We also used ‘water level’ time‐series data and in situ river discharge to establish a rating curve. By use of the rating curve, we converted data on ‘water level’ derived from 7 years (1993–99) of TOPEX/Poseidon data to actual river discharge. On the basis of statistical correlation between discharge and nutrient concentration data collected in 1987–88 and in 1998–99, we estimated the total amounts of freshwater and material fluxes transferred by the Yangtze River during the 1990s. The result reveals that an overall, but very slight, increase in freshwater and material fluxes occurred during the 1990s. Copyright © 2005 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]