Recently, the concept of river Eco-Engineering has become more and more popular in Taiwan. However, most engineers are confused in river Eco-Engineering for its hard designing and safety issue. To solve the above problem, the purpose of this work is to develop the planning handbook (including flowchart and key points of design) and a GIS-Based system for river Eco-Engineering. Furthermore, the developed handbook and system will be applied in Toucian and Zhonggang rivers to demonstrate the applicability for river Eco-Engineering planning and design.
The study will be fulfilled in three years. This report presents the results of the third year, including the review of studied cases in Toucian and Zhonggang rivers, the planning and design of Eco-Engineering for Ke-Zi-Hu river, and the development of information system internet edition. Based on the results of 2-dimensional flow simulation, it shows that the scouring potential around the toe of levees at Jhulin bridge and Yuanlin irrigation canal can be reduced significantly through the construction of dikes. Besides, a suitable dredging strategy around the Dongxing bridge in Zhonggang river can great reduce the scouring potential near the piers.
For the planning and design of Ke-Zi-Hu river, the downstream reach of Guanxin bridge is selected. Based on the planning handbook, it shows that the safety of embankment is satisfied under 10-year flood event, except the cross section 6. To reduce the potential risk of embankment failure in section 6, a drop structure with 6 steps is designed and the 1-dimensional flow simulation results indicate that the velocities near section 6 can be reduced with 14%.
Based on the studies of previous years, an internet edition of information system is developed with the major features including: design and tentative calculating for Eco-engineering, online help for information system, and downloading of project reports.