一、设计排水量 (一)设计排水量的规模 设计排水量的规模是决定排水沟断面的基础,作为原则就排水沟及集水沟而言,以十年一遇的频率,就截水沟而言,以五年一遇的频率(但是,在火山性土壤地带以十年一遇的频率)来考虑发生最大流量(以下称为最大流量)作为标准。〔说明〕 First, the design of drainage (A) the size of the design of the drainage design The size of the drainage is to determine the basis of the drainage channel section, as a principle of drainage ditch and catchment, the frequency of ten years, in terms of intercept ditch, Consider the maximum flow rate (hereafter referred to as the maximum flow rate) as the standard at the frequency of once in five years (however, at a frequency of ten years in volcanic soils). [Description]