基于社会总投入最低的长沙市雨水系统设计重现期研究

设计重现期不仅是暴雨强度公式的重要组成部分，也是雨水排水系统规划与设计的重要参数，重现期选用的合理与否直接关系到城市防洪排涝的安全。为此，以长沙市新开铺污水厂纳污区的青山路、杉木冲路、湘府路三条支系为例，基于社会总投入最低的雨水系统设计重现期分析方法，合理地确定长沙市雨水系统设计重现期。结果表明，长沙市雨水系统规划设计重现期对于一般地区重现期推荐取值3年，重要地区重现期推荐取值5年，为减少城市发生道路积水与内涝提供了参考。

Study on Design Return Period of Rainwater System in Changsha Based on Lowest Social Total Investment

Design return period is an important part of rainstorm intensity formula as well as the important parameter of planning and designing rainwater drainage system. The rationality of design return period is related to the safety of the urban flood control and drainage. Taking three branches of Qingshan road, Shamuchong road and Xiangfu road in the pollutant range of Xinkaipu Sewage Plant as an example, based on the lowest total social investment of rainwater system planning design return period analysis method, the design return period of rainwater system in Changsha was determined reasonably. The results show that Changsha rainwater system planning design return period are recommended three years for general areas, and it is recommended five years for important areas, which provides reference for reducing the occurrence of road water and water logging.