前言一九七二年美国J. Y. 丁(Ding)提出了变动单位线,建立了一套理论公式,并提出具体解算方法,给非线性单位线增添了一条新途径、新分析方法。本文拟针对丁氏所提出的变动单位线中的若干问题,作如下评述。一、丁氏变动单位线的理论基础评述丁氏变动单位线的理论基础,简单地说就是非线性马斯京根楷蓄方程和河道水量平衡方程的合解,引入巴克梅蒂夫变动水流函数(Bakhemeteff varied flow function),再通过 Preface In 1972, J. Ding proposed the change unit line, established a set of theoretical formulas and put forward specific solution methods to add a new way and a new analysis method to the non-linear unit line. This article is intended to address several issues raised by Ding’s unit line of change and make the following comments. First, the theoretical basis of Ding’s unit line of change Comment Ding’s unit line of change theory, simply put is the nonlinear Maskingenk equation and river water balance equation of the solution, the introduction of Buckmeetu changing water flow function (Bakhemeteff varied flow function), and then passed