冲积河流河床稳定性综合指标

Synthetic Index of River-Bed Stability for Alluvial Rivers

冲积河流河床稳定性指标在实践中是判断河流泥沙运动强度、沙丘运动引起的河床变形强度和划分河型的依据。河流动力学研究成果表明,河床纵向稳定性取决于河道纵向水流输沙能力,而纵向水流输沙能力与纵向水流参数成比例。类比于纵向稳定性与纵向水流参数的关系,认为横向稳定性与横向水流参数成比例,以及河床稳定性综合指标取决于纵向稳定性与横向稳定性的对比。经推导,得到了反映水流动力因素、河床几何尺寸和边界特征的河床稳定性综合指标一般表达式。根据天然河道和模型小河的河型资料,确定河床稳定性综合指标。该指标反映了河床综合稳定性且可以用来进行河型判别。

The synthetic index of river-bed stability for alluvial rivers is used to judge the intensity of sediment movement and river-bed evolution caused by sand dune movement, and to distinguish river pettern as reference. The research findings of river dynamics show that the longitudinal river-bed stability has a relation with the longitudinal sediment transport capacity which is proportional to the longitudinal flow parameter. By analogy with the relation between the longitudinal river-bed stability and longitudinal flow parameter, the transverse river-bed stability is assumed to be proportional to the transverse flow parameter. The synthetic index of river-bed stability is determined by the longitudinal river-bed stability in contrast to the transverse river-bed stability. Through derivation the general formula is obtained, which reflects the flow dynamic factors, the characteristics of river-bed geometry and boundary. According to the data of the river pattern of natural and model rivers, the synthetic index is determined. This index reflects the river-bed synthetic stability and can be applied to distinguish river patterns.