Study on comprehensive rainstorm formula based on rainstorm attenuation characteristics in Zhenjiang City of Jiangsu Province

It is an important basic work for urban flood and drainage planning and design to calculate the intensity formula of rainstorm with different duration.The minutely-measured rainfall data from 1981 to 2016 in Dantu Meteorological Station of Zhenjiang city of Jiangsu Province, was assembled to establish the relationship between rainstorm intensity and duration.The rainstorm intensity formulas for all of the single return periods were derived based on the rainstorm attenuation law, and then the comprehensive rainstorm formula applicable to different return periods was explored by drawing on the rainfall force formulae.The results show that, the rainstorm intensity attenuation index of 1~24 h in different return periods are approximately 0.683.The compiled comprehensive rainstorm formula could be utilized for design storm calculation of any duration (1~24 h) and any return period (2~100 a), and the relative and absolute root mean square error of the comprehensive formula are 3.874% and 0.025 mm/min,which conforms to requirements of the standard, respectively.The research results can provide basic support for Zhenjiang city to build an integrated drainage, flood and waterlogging control system and promote the construction of sponge city.