Analysis Of Urbanization To The Hydrological Factor And Study On Urban Stormflood Control

With the development of society and economy, Zhejiang provice urbanization is accelerating, the urbanization level is up to56%in2005from14%in1978, and in2009its up to57.9%. The shortage of urban land causes some of the cities have to develop in the lowland region, some of the construction cities occupied river ways.it increases the risk of urban flood. Urban flood could cause the inland inundation but on the other hand it’s also an important water resource for the urbans.if we could make good use of urban flood, we could save urban water resources and benefit the cities.This article’s object is to make the example of yiwu city, studying the influence of urbanization towards rainfall and runoff, abstracting the experience and lessons of urban flood control and flood drainage then give some reasonable suggestions for urban flood control and management of zhejiang province.(1) The analysis of flood damage:by reading related documents, engineering survey,visiting related departments to collect the information of typical urban flood damage in Zhejiang province,then analysis the main causes of it.Analysis the contributing factors of flood damage based on case "090621" of Yiwu city.(2) The analysis of urban development:to abstract the information from satellite remote sensing images taken at different time, to know the development of urban land usage of Yiwu city at different time, analysis the development of underlying surface conditions to provide basic information for the study of change of rainfall and runoff according the development of urbanization.(3) The influence of urbanization to hydrologic features:by the comparison of rainfall data of the same rain between urban rainfall stations and suburb stations and the comparison of rainfall data of different rains of the same rainfall station to study the influence of urbanization to rainfall and rainstorm; to analysis the influence of urbanization to storm rainfall and water storage space according to the change of underlying surface.(4) The study of urban flood control:to read foreign and domestic related articles and research results,then propose the measures to control the flood in our province according to our unique topography and layout of buildings.