基于河流阻力参数与活动指标的河型判别法

River pattern discriminating method based on resistance parameters and activity indicators

冲积河流在行进过程中受阻力作用,河道断面形态及平面形状参数将作调整,以适应不同的水沙条件,并趋向河流的相对平衡状态,由此导致不同河型的产生。决定河型两个主要因素:一个是水流推动力,一个是河流活动性。河流水流所受到的阻力与河流水流推力,是一个问题的两个方面,是作用力与反作用力。基于河流阻力规律,考虑植被对河岸强度的影响,通过引入河床与河岸活动指标构成的河流活动指标,分析得到了表征河型变化的判别标准曲线,经模型小河资料和天然河流资料检验发现,提出的河型判定参数能够很好地区分河型类别。

An alluvial river is subjected to bed resistance against its water flow and tends to reach a relative equilibrium state in different river patterns since the parameters of its channel cross-section morphology and plane form are changing as a result of adapting to the varied flow and sediment conditions. Two main factors determine the channel pattern of a river： the flow＇s driving force and the river＇s activity, and the thrust and resistance of river flow represent the forces of action and reaction respectively. This paper adopts a riverbed activity indicator and a bank activity indicator for channel patterns and considers the flow resistance law to construct river patterns discriminating curves. Also, the effect of riparian vegetation on riverbank strength is taken into account in the construction of the curves. These indicators are proved effective in deciding different river patterns by using selected datasets from laboratory tests and natural rivers.