Abstract: Rainstorm intensity formula is an important basis for calculating the rainstorm in urban flood control and drainage or waterlogging system. Selecting an appropriate formula directly affects the scale and efficiency of urban flood control and drainage system. In this paper we compared the rainstorm intensity formulae of water conservancy industry and municipal industry in China, and investigated the influence of the two formulae on calculation result by parameter optimization in accordance with criterion. Results indicate that (1) The SCE-UA algorithm can effectively solve the problem of the complex nonlinear rainstorm intensity formula. (2) The fitting effect of the rainstorm intensity formula of municipal industry is better than that of water conservancy industry. The research result would be of great significance for an improved drainage and waterlogging system and reducing rain flood disaster.

Key words: rainstorm intensity formula, SCE-UA algorithm, parameters optimization, LWAS criterion, MAS criterion