Author(s): Nai-Chin Chen; Kwan Tun Lee
Linked Author(s):
Keywords: Time-varying IUH; KW-GIUH; Rainfall intensity; Rainfall-runoff modeling
Abstract: Time-varying instantaneous unit hydrograph (IUH) has been shown promising to be applied for rainfall-runoff simulations. The geomorphologic IUH (GIUH) proposed by Rodriguez-Iturbe and Valdes (1979) is one of the physical based models that can produce the time-varying IUH. In performing the GIUH model, the runoff travel times through different flow paths need to be known. Previous research has shown successful to apply the kinematic- wave theory to solve the runoff travel times to form a kinematic wave based GIUH model (KW-GIUH). Consequently, the IUH generated by the KW-GIUH is shown explicitly varying with rainfall intensity and watershed roughness conditions. In this study, the method for obtaining the temporal rainfall intensity used to generate the time-varying IUH was revised. Hydrologic records from two watersheds in Taiwan were collected to verify the revised approach. The results show that better simulations can be obtained from the revised method especially for concentrated rainstorms cases.
Year: 2005