Researches On The Optimization Model And Path Of The Urban Compactness Of Changsha

In the process of rapid urbanization,problems like contradiction between development and land resource,environmental damage,loss of open space occurred highlights,which make the sustainable development a hot issue.The theory of compact city was introduced into China in the early 21 st century,and quickly attracted the attention of scholars and the government,the theory is considered to be an important mode to achieve sustainable development,as it advocates high density,compact space and mixed land-use.Through analyzing and summarizing the domestic and foreign research on the connotation,space form and compactness of the compact city,this paper summarizes four essential characteristics: the 1st one is compact form,different cities choose their own suitable forms,space form is considered compact on account of reduced demand on land,high efficiency and high quality evaluation of urban development.The 2nd one is higher urban density which is advocated by the theory,but it isn’tequal to compact,since compact are also related to the urban efficiency and developing quality.The 3rd one is mixed land-use,which gives birth to the reduce of long distance travel,the increasement of space diversity and the efficiency of land-use.Satisfying the urban efficiency is the last characteristic.The optimal urban efficiency is the main purpose of the compact city.Changsha is the capital of hunan province and the important center city in central China.The measurement and optimization research of Changsha’s compactness will promote the sustainable development,and provide references to cities of similar scale and stage of development.Based on the connotation analysis and current situation of Changsha’s development,this paper constructs an integrated index system which includes indexes of five aspects like compactness of the external form and interior space,urban efficiency,Compact trend,eco-efficiency.Changsha’s urban compactness in the year of 1996-2014 is measured.By analyzing of its characteristic and dynamic change,we get to know that the degree of the compact ness grows fast in the early stage,while it’s fluctuating upward after 2008.Understanding the influence mechanism of urban compactness has benefit to put forward effective optimization paths.The analysis of Changsha’s historical development and the data in multiple aspects shows that urban expansion influences the compact degree of external morphology,and the way of land-use is a major determinant of compact degree,while appropriate population agglomeration,the industrial adjustment,proper public transport development and government regulation can also promote the compact degree.By the foregoing analy,this article put forward six optimized path as follows: determining the reasonable compact space structure,integrating urban transportation and land-use with TOD mode,implementing the mixed land-use for short distance travel,developing the underground space rationally,resource integration by urban renewal and reasonable guiding policy.Changsha is sure to development compactly through these methods.