Research On The Mechanism Of Functional Detachment In Megacities

With the acceleration of China's urbanization,the issues of "megacity disease" is becoming more serious.Chinese scholars have explored the issue from various angles and done abundant researches.On the basis of previous studies,this paper will continue to explore and study how to resolve the "megacity disease"situation from the angle of a dispersion mechanism.This thesis follows the logical structure of "one-two-three-four":"one line"(that is,the main problem about dispersion mechanism of megacity function system);"two angles"(that is,static deconstruction and dynamic mechanism)to analyse the megacity function system;"three" refers to the three elements of a function system(including the subject of function,the carrier of function and the object of function);and "four" kinds of mechanisms of dispersion of megacity function system(i.e.,the power,mode,path,stage of functional dispersion).Summary of the full paper,the main contribution and new points are as follows:First,based on the analysis of megacity "expansion disease",,this thesis deconstructs the static function structure of megacity:it explores the essence of the city;the definition of urban functions;from the three dimensional angles of classification,layering and grading to clarify the issue of "what the city function is",and to integrate the different scholars' views about the understanding of the city function into a whole framework;to analyse the functional structure of the mega cities from three angles of subject,carrier and object.Secondly,based on the static state of deconstruction,this thesis made dynamic analysis on the inner mechanism of city functions dispersion:explore the common are between a megacity and a regular city in terms of their function;and discuss the issues of "who will disperse?","how to disperse?","where to disperse?";we also explore the general pattern and the main path for dispersion,and summarized the characteristics of each stage.Thirdly,this thesis summarized the valuable management experience of foreign megacities,such as London,New York,Tokyo and Seoul;It analysed the difficulties and key points of urban functions dispersion in China,putting forward the basic principles of "re-dispersion",and discussed the approaches of megacity function "re-disperse" and "re-dissolute" in the future in China,so as to further explore the problems of "who to?","how to?" and "where to?".Fourthly,on the basis of qualitative research,this thesis makes a quantitative measure on the past megacity function dispersion of mega cities,in order to verify the theory and provide the realistic basis for solving problems.(1)Constructs the index system and model to measure the state of megacity function dispersion from the subject,carrier and object of function.(2)Empirically measures the dispersion state of Beijing in 2000-2010 under the indicators of the subject,carrier,object of function.(3)The results showed that:Beijing has made some achievements in the urban internal spatial dispersion in 2000-2010,but there is still space to be further developed.In the view of dispersion stages,the stages and the stage characteristics of city function dispersion of Beijing during 2000-2010 as generally consistent as other city;from the dynamic mechanism and the dominant mode of dispersion,Beijing is mainly dominated by the government,to promote the object of city function to disperse along "the waves" path through industrial upgrading and urban planning,and to realize the carrier of city function expansion to periphery area through the urban planning function;but because the government dominated mode is mainly through industrial policy or administrative restrictions to promote dispersion of function subject,it is difficult to promote the dispersion of the function object led by the market;coupled with the lagging of government's dispersion and construction of function carrier,the majority of high-quality resources still gathered in the capital,it did not expand to the further new urban development area and ecological conservation development areas,thus worsening the urban "megacity disease" situation.Fifthly,on the basis of quantitative research on the past dispersion of mega city functions,this thesis puts forward the megacity and its surrounding city function transplant scheme,and constructed the corresponding the function index system and its model;taking Beijing as an example,against the Beijing-Tianjin-Hebei integration scheme,we made the empirically research on function matching Beijing-Tianjin-Hebei city group from the three aspects of function structure,function relation and function power.Results show:Tianjin and Beijing have higher matching degree in function structure,function connection and function dynamic,Langfang and Beijing have a relatively high matching degree on function structure,function relation.At the same time,considering the most likely "rejection”occurring in the process of megacity functions dispersion,the thesis suggests "monitoring" and "care" in the process of transplant from three aspects of dispersion dynamic,dispersion mode and dispersion path.