Simulating typhoon-induced storm hydrographs in subtropical mountainous watershed: an integrated 3-layer TOPMODEL

J.-C. Huang (1) , T.-Y. Lee (1, 2) , S.-J. Kao (1)

1 Research Center for Environmental Changes
2 Dept. of Bioenvironmental Systems Engineering

A three-layer TOPMODEL is here constructed by integrating three components, diffusion wave approach into surface flow, soil moisture deficit into interflow and exponential recession curve function into base flow. Sensitivity analysis reveals that D (soil depth), K (hydraulic conductivity), and m_i (soil moisture decay) predominate simulated hydrograph shape and total discharge, yet, there are distinct effects on the three flows. A subtropical mountainous watershed, Heng-Chi and eighteen typhoon-induced storms with various rainfall type and wide-ranged total rainfall (81 to 1026 mm) were applied. The global best-fitted combination gives an average efficient coefficient of 75.1% and 76.0% for calibration (14 cases) and validation (4 cases), respectively. Most discharges of validation events fall within the 90% confidence interval derived from calibration events. Those results demonstrate the capability of the 3-layer TOPMODEL in subtropical watershed. Meanwhile, the upper confidence limit is suggested preferably when considering the flood assessment.

Domaines: Interfaces continentales, environnement; Océan, Atmosphère; Sciences de la Terre

J.-C. Huang, T.-Y. Lee, S.-J. Kao. Simulating typhoon-induced storm hydrographs in subtropical mountainous watershed: an integrated 3-layer TOPMODEL. Hydrology and Earth System Sciences Discussions, 2008, 5 (2), pp.1101-1135. ⟨hal-00298947⟩