The “Mechansim of urban storm and flood disasters under a changing environment” is a key national R&D project titled “Monitoring, early warnings, and preparedness for major natural disasters”, which is led by Prof. Zongxue Xu. This project addresses issues such as urban flood monitoring, early warnings and emergency responses in China. The project will mainly focus on investigating how urbanization affect rainstorm events, probing into the physical mechanism behind the impact of urban rain island effect. This investigation will reveal the influence of urbanization on rainstorms and the mechanisms whereby they mutually impact on each other, unteasing the relationship between urbanization development and rainstorm events. The study will establish a quantitative index and technology for assessing the effect of urbanization on runoff generation and routing, and will entail a comprehensive examination of how the process of urbanization impacts on runoff generation and routing. The project will establish the theoretical basis for revealing the impact of the influence mechanism of urbanization on rainstorm events and on the process of runoff generation and confluence. An urban flood simulation and decision support system with the functions of early warning, flood simulation, disaster assessment, and regulation and control will be developed on the basis of the results of the study. Pilot models will be developed in the four representative cities including Beijing, Jinan, Shenzhen, and Chengdu, incorporating local flood control and drought relief systems. These models will result in greater precison of flood forecasting, enhanced capacities for emergency flood management, and capacity development in disaster prevention and reduction.