As channel evaluation for abandoned channel restoration design, this study sought to exam channel changes from the past to the present and predict subsequently occurring river responses. For the methodology, channel g...As channel evaluation for abandoned channel restoration design, this study sought to exam channel changes from the past to the present and predict subsequently occurring river responses. For the methodology, channel geomorphology changes were evaluated through image analyses of annual aerial photographs to complement the limited river data. Channel responses were predicted using an analytical stable channel model, the SAM (Stable Channel Analytical Model) program, based on a stability theory as well as empirical equations for equilibrium channel. The results of the geomorphological channel changes showed that channels became narrower and bed levels became lower, whereas vegetated bars expanded. The channel response prediction results, narrower channels with deeper depths and mild slopes, were expected compared with the current condition. The channel response, obtained by the field measurement data, image information, and stability theory, are in relatively good agreements showing the reliability of the application suggested in this study. Consequently, the comprehensive channel evaluation approach is expected to be applicable to abandoned channel restoration designs from the aspects of channel geomorphology and hydraulics.展开更多
The viewpoint of a river is changing as people regard the river as water-friendly space where they can enjoy and share the space beyond the simple purpose of flood control alongside the improving social level. The flo...The viewpoint of a river is changing as people regard the river as water-friendly space where they can enjoy and share the space beyond the simple purpose of flood control alongside the improving social level. The floating islands installation was planned featuring three islands. The river’s flow and channel stability could be changed when new structures are built in a river. Hence an analysis of the hydraulic characteristic changes should need. The hydraulic model experiment in this study sought to review the impacts of the floating islands installation on the safety of flood control and stability of river channel. This study analyzed the hydraulic features affecting the surrounding stability when installing floating islands and proposed stable floating islands layout in terms of hydraulics based on the experiment results.展开更多
文摘As channel evaluation for abandoned channel restoration design, this study sought to exam channel changes from the past to the present and predict subsequently occurring river responses. For the methodology, channel geomorphology changes were evaluated through image analyses of annual aerial photographs to complement the limited river data. Channel responses were predicted using an analytical stable channel model, the SAM (Stable Channel Analytical Model) program, based on a stability theory as well as empirical equations for equilibrium channel. The results of the geomorphological channel changes showed that channels became narrower and bed levels became lower, whereas vegetated bars expanded. The channel response prediction results, narrower channels with deeper depths and mild slopes, were expected compared with the current condition. The channel response, obtained by the field measurement data, image information, and stability theory, are in relatively good agreements showing the reliability of the application suggested in this study. Consequently, the comprehensive channel evaluation approach is expected to be applicable to abandoned channel restoration designs from the aspects of channel geomorphology and hydraulics.
文摘The viewpoint of a river is changing as people regard the river as water-friendly space where they can enjoy and share the space beyond the simple purpose of flood control alongside the improving social level. The floating islands installation was planned featuring three islands. The river’s flow and channel stability could be changed when new structures are built in a river. Hence an analysis of the hydraulic characteristic changes should need. The hydraulic model experiment in this study sought to review the impacts of the floating islands installation on the safety of flood control and stability of river channel. This study analyzed the hydraulic features affecting the surrounding stability when installing floating islands and proposed stable floating islands layout in terms of hydraulics based on the experiment results.
