Study on the Change of Rainfall Characteristics in Hangzhou's Urbanization Process

With the development of the economy and expansion of the city size, urbanization has more important effects on rainfall characteristics. This paper takes Hangzhou for example, uses measured data of rainfall stations, and analyses the influence of urbanization on rainfall characteristics. The results show that the urbanization has changed the Hangzhou's rainfall characteristics, and the heavy rain occurred probability increases, the flood disaster is more and more frequent.