河床変動の研究―特に河口付近の浚渫が河床に及ぼす影響について―

Abstract

The river is generally always changing its regime due to natural external forces and alsoartificial works. The river changes its form of channel which we call meandering and alsoits longitudinal and cross sectional form which we call scouring and deposition. So it is avery important problem to stabilize the river flow in river regulation works. In this paper, the author treated mainly to discuss the river bed variation due to dredging work in theestuary. At first, the author solved theoretically the variation in the case of non-uniformflow. By an approximate solution, it was cleared that the irregularity of the river bed isdamped exponentially with time and transformed downward in the case of sub-critical flow, but in the case of super-critical flow, it is transformed upward and in both cases, it dimini-shes with time. By numerical calculations and experiments by a sand flume, the theoreticalsolution was verified.