摘要
Various approximate formnlas for calculating the critical depth in trapezoidal channels have been proposed by I. I. Agroskin, I. M. Sharmanovsky, Ding Junsong (丁君松), Huang Kezhong (黄克中), Li Zhongyi (李忠义) et al. during this decade. But all of these formulas are restricted within certain respects of application.
