抄録
It is well known that groynes navigate mainstream effectively to protect a river basin. An associated dead water zone can be a valuable space for various aquatic eco-system. In contrast, such a closed water environment reduces water quality rapidly, and it is therefore of vital importance to consider not only hydrodynamic properties but also mass transfer mechanism beneath the mainstream and the dead water zone. We conducted turbulence and dye concentration measurements in a laboratory flume by using PIV and LIF techniques, respectively, and based on the present results, a phenomenological flow model was developed which describes comparison of large-scale gyre structure and mass transfer coefficient among the different rank number.
