小比例尺的正态悬沙模型,在选沙方面存在一个大的困难,就是要求模型沙很细,而模型沙一细,就容易出现胶体化学中的电化学现象。也就是因水中电解质及其含量的不同而产生不同程度的凝聚或分散现象,改变颗粒级配的组成,从而改变泥沙的水力学特性, The small-scale normal suspended sediment model has a big difficulty in sand sorting. It requires that the model sand be very fine, while the model sand is fine, electrochemical phenomena in colloidal chemistry tend to occur. That is, due to the different levels of electrolytes and their contents in the water to produce cohesion or dispersion of varying degrees, changing the composition of the particle gradation to change the hydraulic properties of sediment,