无资料地区设计洪水计算的途径较多,如相似流域面积比拟,地区综合经验公式或者用暴雨径流方法。本文介绍以洪水调查(或其他手段)确定的近二、三十年来的最大洪水或几次大洪水为基本依据,提出无资料地区设计洪水计算的一种方法。它可以提高无资料地区设计洪水计算的精度。(一)计算方法对于大多数中、小河流,久远的历史洪水,多属传说或史志资料,洪水痕迹难考证,洪水难以确切定量。而近期发生的几十年一遇的洪水,因见证的老年人尚在,记忆较深,洪水痕迹容易调查,一般能够得到可 There are many ways to calculate design floods in the non-material areas, such as the similarity of similar drainage area, regional comprehensive empirical formula or stormwater runoff method. This article presents a method based on floods (or other means) to determine the largest flood in recent two or three decades or several major floods as a basis to propose a method for calculating floods in unintentional areas. It can improve the accuracy of design flood calculations in uninformed areas. (A) Calculation Method For most of the small rivers, long history of floods, mostly legend or historical records, difficult to verify the traces of the floods, the flood is difficult to quantify quantitatively. In the recent decades, the number of floods witnessed by the elderly is still low, the memory is deep, the traces of floods are easy to be investigated, and the general can be obtained