Utilize hydraulic characteristics in ecological landscape river planning—A case study on Beijing Tanglewood Music Valley

For the general question of how to maintain self-purification when reclaimed water is used in ecological river planning, the authors took a case study on the design of the water cycle system in Beijing Tanglewood Music Valley where hydraulic characteristics were properly utilized to optimize the physical purification process in the landscape river and reservoir. Specifically, the authors analyzed the mechanism of increasing dissolved oxygen driven by spiral flows in river bends, proposed the relationship between geometric properties of river cross-section and the velocity and depth of river flow, and also suggested that an improved photosynthetic layer distribution, along with a better landscape view, could be reached by appropriately raising the bottom of the reservoir. In the details of water circulation design, the authors recommended an optimized layout for relative positions of water intake and backwater zone, which would force convection between upper and lower water layers to overcome the thermal resistance. This study could serve as a reference for future planning of water cycle system in ecological landscape project.