Abstract: An HEC-HMS (Hydrologic Engineering Center’s Hydrologic Modeling System) is built to research the rainstorm flood response mechanism of Qinhuai river drainage basin in the background of rapid urbanization. Three land use scenarios are set in the model natural development scenario, woodland restrictive policy scenario, and paddy field restrictive policy scenario in the year 2028 predicted by CA-Markov model. The HEC-HMS model is calibrated and validated to be applicable for flood simulation and flood response research under different land use scenarios. Results implies that the smaller the flood scale, the stronger the flood response. With the development of urbanization, the impact of land use on rainstorm flood aggrandizes the future flood peak and flood volume increase the most sharply under natural development scenario, followed by those under paddy field policy scenario and woodland policy scenario. The research findings provide a new idea for the analysis of storm flood response of land use cover change in the Qinhuai River basin, and also have some guiding significance for flood control planning and construction of the basin.

Key words: flood response, land use cover change scenario, CA-Markov, HEC-HMS, Qinhuai River Basin