Especially in past,that interval unit hydrograph of instantaneous unit hydrograph for watershed runoff concentration was not thought as unit system or dimension is an incorrect statement.

• 结果表明,在流域汇流瞬时单位线法中长期以来认为时段单位线为无因次的,该提法不妥,时段单位线应为有因次,具有流量单位。