Technical Studies

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 Zhonggang river to demonstrate the applicability for river Eco-Engineering planning and design.

To accomplish the work, the background of Zhonggang river, including hydraulic characteristic, ecological environment, and past flood damage record is collected firstly. Then, the Zhonggang river is divided into several reaches according to stream classification system (Rosgen, 1994). Based on the classification results combining field exploration and numerical model simulation, the in-stream building effect for river morphology and ecological environment are examined. Furthermore, the flood damage is mainly due to: (1) local flood due to low-lying land; (2) the uncompleted damage-proof structures; and (3) flow strike the embankment directly with high velocity in some reaches.

According to the analysis of river characteristic mentioned above, the reaches of new Zhonggang river bridge, Yuanlin irrigation canal in Sanwan township, and upstream of Funan bridge in Nanhe creek are selected for planning and design of river Eco-Engineering. The application results show that the developed design flowchart is applicably for real world problem. Besides, the design key points are modified in a clear tabular form. Each modification in the planning handbook is incorporated into the developed information system to reduce the difficult for river Eco-Engineering planning and design.