www.hydrol-earth-syst-sci-discuss.net/7/3803/2010/ doi:10.5194/hessd-7-3803-2010 © Author(s) 2010. This work is distributed under the Creative Commons Attribution 3.0 License. Towards improving river discharge estimation in ungauged basins: calibration of rainfall-runoff models based on satellite observations of river flow width at basin outlet 1Department of Civil and Environmental Engineering, University of Yamanashi, Japan 2National University of Ireland, Maynooth, Co. Kildare, Ireland Abstract. Rainfall-runoff models are common tools for river discharge estimation in the field of hydrology. In ungauged basins, the dependence on observed river discharge data for calibration restricts applications of rainfall-runoff models. The strong correlation between quantities of river cross-sectional water surface width obtained from remote sensing and corresponding in situ gauged river discharge has been verified by many researchers. In this study, a calibration scheme of rainfall-runoff models based on satellite observations of river width at basin outlet is illustrated. One distinct advantage is that this calibration is independent of river discharge information. The at-a-station hydraulic geometry is implemented to facilitate shifting calibration objective from river discharge to river width. The generalized likelihood uncertainty estimation methodology is applied to model calibration and uncertainty analysis. The calibration scheme is demonstrated through a case study for simulating river discharge at Pakse in the Mekong Basin. The effectiveness of calibration scheme and uncertainties associated with utilization of river width observations from space are examined from model input-state-output behaviour, capability of reproducing river discharge, and posterior parameter distribution. The results indicate that the satellite observation of river width is a competent surrogate of observed discharge for the calibration of rainfall-runoff model at Pakse and the proposed method has the potential for improving reliability of river discharge estimation in basins without any discharge gauging. Discussion Paper (PDF, 9211 KB) Interactive Discussion (Closed, 4 Comments) Final Revised Paper (HESS) Special Issue Citation: Wenchao Sun, Hiroshi Ishidaira, and Satish Bastola: Towards improving river discharge estimation in ungauged basins: calibration of rainfall-runoff models based on satellite observations of river flow width at basin outlet, Hydrol. Earth Syst. Sci. Discuss., 7, 3803-3836, doi:10.5194/hessd-7-3803-2010, 2010. Bibtex EndNote Reference Manager XML |
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