Stream construction characteristics in rapid urbanization area: Shenzhen city as a case
快速城市化地区水系结构变化特征——以深圳市为例

Urban River is an important part of urban ecosystem.There are close relationship between stream construction and its ecological function.The form and evolution of stream construction is controlled by geology,topography,soil,climate,vegetation and human activity at local area.At present,human activity,especially urbanization has become the major factor influencing the stream structure.In order to study the effect of urbanization on stream construction,taking Shenzhen city,a rapid urbanization area as a case,which is one of the most rapid urbanization areas in China,by using Strahler classification and Horton laws,this paper analyzed the effect of urbanization on stream length,stream density,bifurcation ratio of rivers,ability of bifurcation of rivers and fractal dimension etc.The result exhibited that:(1)The stream length,stream density and stream number all decreased,especially for the lower order stream from 1982 to 2002.and(2)the ratio and ability of bifurcation decreased of all the watersheds.The stream construction was simplified with time.The fractal dimension of stream construction also decreased with time.(3)The stream construction changing characteristic was different for different watersheds due to the effect of urbanization level.This paper suggested:(1)to improve planning and implement blue-line,strengthen the management of river net and add it to the content of urban planning and managing;(2)to protect the stream in the process of land use change;and(3)to strengthen the control of soil and water erosion,thus decrease the yield of river sediments.