二次元水域における砂州の発達・変動過程に関する研究(3) -三角州の発達・変動過程のシミュレーション-

Abstract

In this paper, the delta formation process in a laterally wide basin wasformulated based upon the experimental results described in the previous papers ofthis series of research, and some numerical simulations were carried out to examinethe formulation.The results obtained are summarized as follows:The delta formation process is divided into three stages; in the first stage, thedelta develops mainly longitudinally; in the second stage, it develops mainlylaterally; and in the third stage, it develops in all directions keeping a nealy similarshape in average.In the first and the second stages, the flow expands on a delta plain withoutstream channels, which is well analyzed by a two-dimensional flow and bedvariation model. In the third stage, however, some stream channels are formed andmigrate on the delta plain, which is analyzed by a one-dimensional flow and bedvariation model.