The Equivalent Frequency Transfer Function of Nonlinear Runoff Models and Its Application to River Network

Surakha Wanphen
Graduate School of Engineering, Hokkaido University

要旨

An application of the Equivalent Frequency Transfer Function (EFTF) was applied in this study to estimate the amount of discharge. This EFTF has originally been used in control engineering to analyze non-linear elements. Luai H. and Fujita M., in the previous studies, had derived the EFTF for several runoff models based on a mountainous slope, however, it is not practical for the real situation. Therefore, the aim of this study is to develop an application of EFTF of nonlinear runoff model with large magnitude basin. Gain, time lag characteristics and vector locus are proposed in order to investigate the efficiency of the transfer function. Moreover, approximation of discharge from available rainfall data has been achieved from moment method.