中文摘要：

基于扩散理论,分析了国内外主要平衡悬沙剖面公式自由面边界条件内在的不合理性及其原因,并结合常数型和线性型悬沙扩散系数的分布特征,应用几何平均法建立了平方根型的悬沙扩散系数表达式,推得了平衡悬沙剖面的新指数公式。通过收集、整理与分析大量水槽与河流实测悬沙资料,对提出的悬沙扩散系数和平衡悬沙剖面公式与van Rijn公式、张红武公式进行了分析比较。研究结果表明,新指数公式不仅对平衡悬沙剖面的刻画精度较高,而且具有表达式特别简洁、床面含沙量为有限定值和可直接解析积分的特点,既利于理论分析,又便于工程应用。

英文摘要：

Based on the diffusion equations of suspended sediment concentration （SSC） , we analyzed the inherent ir- rationality of the free surface condition in some main solutions for the equilibrium profile with different diffusion coeffi- cient expressions, and reconstructed a 1/2 power-law diffusivity expression by geometric mean method according to the distribution characteristics of constant and linear diffusivity profiles, then a new exponent profile was derived for SSC under equilibrium condition in this paper. Through the comparison between the new diffusivity distribution as well as its corresponding SSC profile and a lot of measured data from abundant literatures, together with the study results by van Rijn and Zhang, it is shown that this new exponent profile not only has higher precision in computing SSC, but al- so is characterized by simple expression, limited bed layer SSC and direct integral which are the distinguished features superior to Rouse equation, van Rijn equation and Zhang equation. Therefore, it is a simple and robust profile for the equilibrium SSC with more superiority in theoretical research and practical applications of hydrology, sedimentology and water resources.