REVIEW OF RESEARCH ON STABLE RIVER CHANNEL GEOMETRY, AND STUDY ON EMPIRICAL RELATION FOR RIVER CHANNEL GEOMETRY

Abstract

The dimensionless relationships of width(B*) and depth(h*) to discharge(Q*) for stable channels, such as the rivers with dike in Japan and natural rivers in other countries, having bed materials from gravel to silt-sand were presented linearly within one order zone on log-log graph. The linear relation represented by a set of exponent and coefficient for a wide variety of rivers can be regarded as quite new because those proposed conventionally based on regime concepts were specific for each river. The exponent of Q* for both B* and h* is determined empirically around to be 0.4, which also can be proven analytically and explained theoretically to relate with relative roughness. The coefficients of Q* for B* and h* can be functions of B/h and velocity coefficient. Thus such empirical relation supported by hydraulic parameters enables us to understand the variation of stable channel geometry.