一、计算小流域设计洪水必须以间接计算方法为主中小河流由于数量多,不可能在每条河流上都设立水文观测装置。因此,中小河流上的设计洪水计算,多数是在短缺资料条件下进行的。这就决定其主要是应当利用与洪水形成有关的因素来间接推算。 First, the design of small watershed design floods must be based on indirect calculation method Small and medium-sized rivers as a large number, it is impossible to set up hydrological observation devices in each river. Therefore, the calculation of design floods on small and medium-sized rivers is mostly conducted under the condition of shortage of information. This determines that it should mainly rely on factors related to flood formation to be indirectly estimated.