一是，城市污染物排放量计算；二是，水体水量—水质—生态耦合模型；三是，生态系统良性循环控制目标方程。由这三部分模型方程组合成为“水环境承载能力计算模型”。-One is that urban emissions calculation Second, water quantity, water quality, water ecology coupling model Three is that ecosystem benign cycle control target equation.