Mechanism,Measure System And Demonstration Of Urban Sprawl

Land use/cover change(LUCC)is the core topic of global climate change,and urban sprawl(USP)has become a focus of LUCC research.Most scholars have held denial attitudes to USP.Development associated with USP not only decreases the amount of cultivated land and forest resources,endangers food and energy security,destroys the environment,but also affects biological diversity.Effective measure of the degree of USP and accurate judgment of its characteristics,will not only provide monitoring information of LUCC and urban planning decision-making basis,but also make direct practical contributions to countries and regions with inadequate cultivated land resources.Linyi City of Shandong Province,Regional Central City is selected as case study.By empirical analysis of the pattern of USP,a set of control strategies of USP is presented.The empirical analysis aims to provide theoretical foundation and methodological support for effective control of USP of Regional Central City,from the point to the surface.This article contains three Parts,altogether six Chapters.The first Part includes two Chapters: introduction,domestic and foreign research progress.Chapter 1 includes the research background,the significance of the topic,main contents and general structure scheme.The following Chapter 2 is carried out by literature research as a point of penetration and find the breakthrough point of the thesis: exploring the mechanism and building the measurement system of USP.The second Part,the theory and method sertation,contains 3 Chapters: The mechanism of USP,theories and practices of Controlling USP,and measurement system of USP;By using the Theory of Urban Self-organization,this Part firstly is carried out from the perspective of urban morphology,analyzes the relationship between USP and Dissipative Structure Theory,Synergy Theory,Chaos and Fractal Theory,and Catastrophe Theory,and gets a mechanism of USP.Nextly,the theories of controlling USP,namely,Organic Concentration Theory,Compact City Theory,Smart Growth Theory,and the New Urbanism Theory,are outlined,and the strategies of controlling USP of the typical cities,namely,Great London,Maryland and Portland of the United States,and Hong Kong and Guangzhou of China,are generalized.Chapter 4 is to consider about full recognition of the causes and processes of USP and provide theoretical origin of strategies of controlling USP.Based on the mechanism of USP,the measurement system of USP is built from distinct perspectives,namely,standard setting and influencing factors of measures,selection criteria of measure indices,classification method of measure indices,and integral approaches of multidimensional measures.The third Part is empirical analysis and conclusion(Chapter 6 and Chapter 7,respectively).By using the measurement system of USP,Chapter 6 makes a demonstration analysis on the pattern of USP of Linyi City,and proposes strategies of controlling USP of Regional Central City.At the last part of Chapter 7,a conclusion is abstracted,innovation points are outlined,and further research is set out for the vision.Theoretical studies show that the essence of USP is the structural performance of fluctuation imbalances of self-organization mechanism of urban system.Fluctuation factors such as popularization of private cars,domestic tax-sharing system resulting in excessive pursuit of GDP,can lead to city dysfunction and USP with increasing-entropy on the measurement in urban system.The self-organizing feature of urban system which results in relatively stable and orderly structure at a new balance by the means of substantially negating the original balance,provides a theoretical support of controlling USP.Study also shows that the common features of controlling USP appear decrease of entropy: Compact City Theory focuses on land use overall arrangement of city subsystems,Smart Gowth Theory more focuses on institutional measures of controlling USP with decrease of entropy at city scale,and New Urbanism Theory concerns with humanistic mechanism constructions at community scale.Based on the theory of urban self-organization and existing calculation methods of USP,Measurement System of USP was built.According to the theory of urban selforganization and standard of completeness and mutual exclusivity,the paper set up 6measures,namely,quantitative growth measure,uncontinuity measure,decentralization measure,land-use mix measure,accessibility measure,and open space measure,respectively.The paper proposed 9 evaluation standards of measure index from four aspects: subjective experience,mechanism,basic data,and index performance,and characteristics of indices and their applicable conditions were fully evaluated;at the same time,two new indices were proposed,one can apply to measure the degree of spatial discontinuous.expansion which is named Spatial Expansion Degree Index(SEDI);the other can measure the degree of Per Capita Open Space.The paper put forward classification method of indices which includes Key Performance Indicator and Supported Score Indicator,which can be used to measure the performance of differentindices.20 indices were tested according to the Measurement System of USP.Based on multiple attribute decision making method,the paper also built Integral Approaches of Multidimensional Measures with Entropy Method as the core method.Through empirical study,characteristics of USP of Linyi city are generalized as follows: overall characteristics of USP was unchanged,but its trend was abating;group development of built-up land increased,while agglomerating and radiating effects of central city became weak;its accessibility was enhanced while internal collaborative function of city was on the wane;Urban Growth Boundary(UGB)was out of control and urban open space was reduced.Based on the characteristics of USP,three strategies of controlling USP were proposed: strict control of UGB,promoting agglomerating and radiating effects of central city,and upgrading industry structure,which have a certain directive significance to the developments of Regional Central City.The empirical study shows that,the unidimensional measure cannot guarantee the measure effectiveness,while multi-dimensional measures can provide effective premise.The effectiveness is determined by standard setting and influencing factors of easures,selection criteria of measure indices,classification method of measure indices,and integral approaches of multidimensional measures,and originates in 4aspects: measures setting in accordance with the mechanism of USP,the completeness and mutual exclusivity of measures,the commensurability of measure indices,and the commensurability of measure indices.