Estimating river discharge from earth Observation measurement of river surface hydraulic variables

• Published in: Hydrology and earth system sciences 2011, Vol.15 (6)
• Main Authors: Negrel, J., Kosuth, P., Bercher, N.
• Format: Article
• Language: English
• Subjects: Environmental Sciences
• ISSN: 1027-5606; 1607-7938
• DOI: 10.5194/hess-15-2049-2011

River discharge is a key variable for quantifying the water cycle, its fluxes and stocks at different scales. These scales range from a local scale for the efficient management of water resources to a global scale for the monitoring of climate change. Therefore, developing Earth observation (EO) techniques for the measurement or estimation of river discharge poses a major challenge. A key question deals with the possibility of deriving river discharge values from EO surface variables (width, level, slope, and velocity are the only such variables accessible through EO) without any in situ measurement. Based on a literature study and original investigations, this study explores the possibilities of estimating river discharge from water surface variables. The proposed method relies on limiting assumptions to simplify river flow equations to obtain the values of the hydraulic parameters at a given river station without using ground measurements. Once the hydraulic parameters are identified, the method allows the estimation of the river discharge corresponding to a set of surface measurements of hydraulic variables.