SOIL ENVIRONMENT AND INFILTRATION FLOW IN TIDAL FLAT AT RIVERBANK OF A COMPOUND CHANNEL

Abstract

Functions of low water revetment in a tidal compound channel were investigated in terms of soil environment and infiltration flow as an ecological revetment by field observations. Transport of organic content and fine fraction of soil were accumulated at the depth of -20 cm in tide pool. Turbid water containing fine particle at water surface was supplied to the tide pool during flood tide. Turbid matter is transported down to the deep layer due to hydraulic gradient, whilst tidal infiltration flow occurs weakly in the surface layer. Variation ratio of the hydraulic gradient to low water level was increased by the sedimentation due to floods. Influence distance of the tide pool water on salinity distribution expands with the decrease of low water level in main channel.