EXPERIMENTAL STUDY ON INFLUENCE OF PARTIAL REMOVAL OF PLANT COLONY ON RIVER FLOW AFTER GRAVEL BAR RESTORATION

Abstract

 After gravel bar restoration, without effective maintenance, U-shaped plant colony will be formed and cause deposition of fine sediment, which results in the invasion of exotic plants and the decline of endemic plants to gravel bed. Laboratory experiments clarified that the flow during flood runs into the hollow part of the U-shape, which may induce deposition of fine sediment, and that the downstream region of the U-shape may induce deposition of very fine sediment. It was also shown that the partial removal of the “bottom” part of the U-shape will be most effective for suppression of fine sediment deposition.