最小水流能量损失率理论在河相关系中的应用

APPLICATION OF THE THEORY OF MINIMUM RATE OF ENERGY DISSIPATION TO HYDRAULIC GEOMETRY RELATIONSHIP

本文介绍最小水流能量损失率理论的变分法基础。用该理论导出了航道整治工程前后的河相关系式,并将之用于预估东平水道航道整治工程后的河相。实测值与预估值的比较表明,该理论和该河相关系式是可信的。

Yang C. T. introduced the concept of the theory of minimum rate of energy dissipation to the study of natural strean systems. So far the theory has 'been efficiently applied by Yang and others for the determination of the stability of several rivers. In this paper, the variational principle basis of the theory is reintroduced and applied to the river regulation. We assume that the minimum unit stream power is the same before and after the river regulation engineering, so that an equation of hydraulic geometry is given, that is in which h1 is the average depth before regulation engineering, h2 is the regulated depth, Bi is the width of river before regulation engineering, B2 is the regulated width, Qi is the regulated discharge, and Q2 is the discharge at the discharge at the regulated level after regulation engineering. The equation is applied to the river regulation engineering of Dongping River in he South China for predicting its regulated depths and navigable depths. The comparisons between measured and estimated navigable depths show that the equation is effective.