河流动力学极值原理与熵理论研究综述

Review of Extreme Principle and Entropy Theory in River Dynamics

通过总结分析河流极值原理和熵理论的发展历史,得出结论:阻碍河流变分理论研究与应用的主要问题是是否将河流系统作为开放系统和目标函数的约束条件意见上的分歧,说明了必须把河流系统当作开放系统来研究,而不同的约束条件则对应不同的极值理论(最大能耗或最小能耗原理),两种极值理论之间并不矛盾。重点分析了20世纪90年代以来的河流极值原理最新研究成果,指出进一步的极值理论研究应该着重考虑泥沙参与河床塑造的作用机理,由该理论推导出的河流演变公式中的各项都要具有明确的物理意义。

The authors come to conclusions that the main problems obstructing the development of these theories are an open system and initial conditionds, and that the river system in study must be considered as to be an open system , and different initial conditions correspond to different theories（maximum and minimum energy dissipa- tion theories）. Last, the authors analyse emphatically the new research fruits of these theories since 1990s, and point out that the effect of sediment on evolution process of river should be taken into account to make the formulas more physical meaning.