Influence of geometrical constraints on the evolution of meandering rivers

摘要

The effects of geometrical constraints on downstream river evolution are numerically investigated focusing on the Ikeda et al. (1981) model in this work. Despite its simplicity, this model takes spatial memory effects into account, thus allowing for the description of some basic mechanisms typical of real meander, appropriately. Moreover, the whole dynamics can be reduced to the study of three governing parameters: the Parker number Pa, the decay length D and the basic time scale T. The results obtained by spanning a reasonable range of the parameters D, and Pa, and the relative investigation of bounded river reaches of different shapes and length, lead to some interesting observations and first conclusions. These regard the possibility of understanding and potentially quantifying the future changes that occur downstream of the bounded reach as well as providing some useful suggestions on how to control them.