Measurements of river and lake water levels from space-borne radar altimeters (past missions include ERS, Envisat, Jason, Topex) are useful for calibration and validation of large-scale hydrological models in poorly gauged river basins. Altimetry data availability over the downstream reaches of the Brahmaputra is excellent (17 high-quality virtual stations from ERS-2, 6 from Topex and 10 from Envisat are available for the Brahmaputra). In this study, altimetry data are used to update a large-scale Budyko-type hydrological model of the Brahmaputra river basin in real time. Altimetry measurements are converted to discharge using rating curves of simulated discharge versus observed altimetry. This approach makes it possible to use altimetry data from river cross sections where both in-situ rating curves and accurate river cross section geometry are not available. Model updating based on radar altimetry improved model performance considerably. The Nash-Sutcliffe model efficiency increased from 0.77 to 0.83. Real-time river basin modelling using radar altimetry has the potential to improve the predictive capability of large-scale hydrological models elsewhere on the planet.
Hydrology Research, 2014, Vol 45, Issue 1, p. 148-164
Brahmaputra; Large-scale hydrological model; Radar altimetry; Real-time updating; Climate models; Radar; Rivers; Water levels; Watersheds; Calibration and validations; Cross-section geometry; Hydrological modeling; Predictive capabilities; River basin modelling; Geodetic satellites; Brahmaputra river basin Asia Oriental region; cross section geometry; gauged river basin; 04500, Mathematical biology and statistical methods; 10515, Biophysics - Biocybernetics; Computational Biology; hydrological model mathematical and computer techniques; Nash-Sutcliffe model mathematical and computer techniques; radar altimetry applied and field techniques; Methods and Techniques; Models and Simulations; WATER; SATELLITE ALTIMETRY; RAINFALL PRODUCTS; GANGES RIVER; CALIBRATION; FLOODS; ASSIMILATION; DISCHARGE; DYNAMICS; large-scale hydrological model; radar altimetry; real-time updating; RADAR altimetry