Abstract
　An urban stormwater runoff simulation model that can deal with the surcharged flow and surface flooding in storm sewer pipe systems is presented. This simulation model consists of four sub-models that are catchment modeling, rainfall-loss model，surface runoff model and sewer runoff model. In the sub-model for sewer runoff a SLOT Model is devised. This model can handle both open-channel and surcharged flow with the same governing equations, and the width of the hypothetical slot is physically determined using the properties of the sewer and lateral pipes in existing sewer systems.
　The simulation model is applied to Matsuyama City drainage basin, and the adaptabilities of the model for rainfall-runoff with surface flooding are investigated comparing the observed and simulated runoff results.

【キーワード】：都市流出，流域モデリング，サーチャージ流れ，地表面はんらん，スロット・モデル

*愛媛大学工学部
Faculty of Engineering, Ehime University
**神戸大学農学部
Faculty of Agriculture, Kobe University