变动单位线 u〔I(t—τ),τ〕是线性系统方程中随降雨 I 而变化的核函数,其参数值一般不易求得,势必要采用优选方法。本文在拟定的参数优选准则的基础上分析参数优选值的变化规律,提出参数优选方法和单站综合的方法。通过对比分析,证明变动单位线比线性时段单位线更符合实际情况。 Change unit line u [I (t-τ), τ] is a kernel function of the linear system equation with rainfall I, the parameter value is generally not easy to obtain, it is bound to adopt the preferred method. In this paper, based on the proposed parameter optimization criteria, the change rule of parameter preference value is analyzed, and the method of parameter optimization and the method of single station synthesis are proposed. Through comparative analysis, it is proved that the unit line of change is more in line with the actual situation than the unit line of linear period.