하천의 계획홍수위 결정에 관한 연구 = Study on the Decision of Design Flood Level of River

다국어 초록 (Multilingual Abstract)

Analysis of open-channel flow is needed for the planning, design, and operation of water-resource project. The use of computers and the availability of efficient computational procedures have simplified such analysis as well as making it possible to handle complex and complicated systems. If the flow velocity at a given point does not change with respect to time, then the flow is called steady flow. however, if the velocity at g given location changes with respect to time, then the flow is called unsteady flow And a given instant of time does not change within a given length of channel, then uniform flow, at a time varies with respect to distance, then nonuniform flow, or varied flow.
The steady and unsteady flows are characterized by the variation with respect to time at a given location, whereas the uniform and varied flows are characterized by the variation at a given instant of time with respect to distance. Thus, in a steady-uniform flow, the total derivative dv/dt=0. In one-dimensional flow, this means that ∂v=∂t=0, and ∂v/Xx=0.
In this study, to analyze the flood flow profile characteristics and to apply in the man-made and the natural channel, uniform flow by slope-area method, nonuniform flow by standard step method(HEC-2 model) and unsteady flow by four point implicit method was investigated in this study.
The weighted four point implicit method and Newton-Raphson method were used to solve the finite difference equations corresponding to the St. Venant equations for unsteady flow.
The conclusions drawn from this study are:
1. Information about the input for the man-made channel simulation cases such as unsteady, nonuniform and uniform flow, given by defining a goodness of fit criterion D. Their rates were 0%, 13.4% and 18.7%, respectively. The natural channel cases were -3.9%, 0% and -0.8%.
2. The attenuation of the flood peak is getting larger as friction factoris increased. It was also shown that Froude's number is strongly dependant upon the channel slope and frict.