Research On Complex Problem Of Urban Evolution And Habitant Distribution

Information technique revolution have speed up the step of economic global,and further speed up the process of urbanization development since 1980'.Buturbanization also has brought some negative effects when it has brought economicsglory to us, such as traffic jam and environment pollution, etc. Therefore, it has animportant meaning to city' sustainable development that know the law of urbandevelopment and changing, instruct city planning whit scientific method.Nowadays, the urbanization is being at accelerated development stage in ourcountry. It necessarily affects the changing and reorganization of urban spatialstructure that city' population grow rapidly. The research in this paper make use ofchance of the research on habitants reorganization. The innovations of housing andlabor force resource system have already spread gradually in each big andmedium-sized city. Consequently, the freedom of habitant choosing job anddwelling place and house commercializing necessarily have been the resultsfollowing the development of market economy. Because the main body of theoriginal dwelling form in our country was public-own system, habitants had noright to choice where they lived and was restricted by the their companies underthis system. Therefore, the traits of habitants' jobs and their locus were very similarin the same zone, which was determined by characteristic of the staff's dwelling.Now the commercial houses have no above traits and habitants can choice freelytheir dwellings. Outcome, housing environment, humanistic ethos, accessibility ofjob commuting and suiting children's convenience of going to school have been theprimary factors that influence habitants' choice. The initial staff's housing zonedistributed necessarily has been commercialized by degrees after house innovationand the concomitant limit was eliminated, which made the difference between twozones unobvious and formed the uniform commercial houses system. So thehabitant reorganization came into being, which must affect habitants' distributionand traffic planning of urban greatly. Simultaneity, the evolving process of habitants' reorganization and their tripdistribution will bring many complexity problems, as follows.(1) Alteration of habitants' configuration such as culture, outcome, career andstatus structure and so on.(2) Alteration of trip distribution such as trip direction and trip distance, which willcause the alteration of traffic flow and flow direction that are able to make theinitial traffic system changing and break the original balance.(3) Obvious difference among zones resulting from the multiple influence factorsand psycho logic slant, which will have an effect on a city's sustainabledevelopment.Above problems should be ascribed to many reasons, but the most importantone is habitants' organization freely. In big and medium cities of our country thesephenomena are not distinct now, but these problem must become obvious andinfluence urban sustainable development along with the reinforcing constantlydominant status of market economy, the widening urban extension and thechanging interior structure.Urban system is a subsystem of social system and have complexity charactersof the social system. In view of present complexity science, the present conditionand environment of urban have contained complex and delicate interdependentrelation among social economic factor in fact and is a complex system that is filledup with vitality.The source of habitants' reorganization and their trip distribution complexityis the complexity of urban space structure evolution. Because the space distributionof urban habitants is a key problem to trip generation forecasting and a importantpart of urban space structure. So we only know deeply the law of urban spacestructure in condition of market economic, we can understand the law of habitants'reorganization and their trip distribution in the situation as a whole.Space distribution of urban habitant closely relates to the selection ofresidential location. The selection of residential location of urban habitant is thereason more deeply for trip generation. We can decide the generation condition ofhabitants' trip in widely extent, if we can forecast distribution condition of theselection of residential location, and the calculation of trip generation according tothis conform more with the reality of urban development.In order to research on the law of urban spatial structure applying complexitytheory, this paper have described first the basic character of complexity and havediscussed mainly dissipative structure theory and synergetics of self-organizationtheory, we will finally research some problems applying them, as follows:(1) Research on urban internal spatial structure and its evolution;(2) Research on the law of urban habitants' distribution applying consumptiontheory;(3) Research on the law of urban habitants' distribution and evolution applyingLangevin equation;(4) Research on habitant trip distribution.(1) Research on urban internal space structure and its evolution.We give first two methods describing space pattern in this part, urbanfunction distribution and density gradient change curve. We have discussed theprinciple forming urban internal space structure according to urban agglomerationeffects and land rent. We have discussed particularly the relation between theagglomeration effects and merchant and habitant decision of selection ofresidential location and formation of market equilibrium rent. Through researchon the influence technical progress, property structure upgrade and investment toevolution of urban spatial structure, we have found the reasons of urban extensionand rent curve movement upward. We have discussed finally the complexity aboutevolution of urban spatial structure which is foundation of research on distributionof urban habitant further.(2) Research on the law of urban habitants' distribution applyingconsumption theory.According to consumption theory of economy, habitants consider mainly twofactor when they select residential location, that is to say, how do get maximumutility with minimum cost. Many cost factors are summarized as assemble costand rent cost in this paper, and simplifying analysis of the problems. Habitants canget same utility in different location when they select residential location, but theutility only can be gotten under different cost level, therefore there are a lot ofun-difference utility curves. We have given the general law of selection ofresidential location expansion outward.(3) Research on the law of urban habitants' distribution and evolutionapplying Langevin equation.Langevin equation is a sort of random differential equation which is used todescribe particle's irregular movement under the action of exact force and randomforce together. We assume that habitants' actions are exact and objectivecompletely when we research on the law of habitants' distribution withconsumption theory, but the fact is not completely such in fact. Becauseinformation is incomplete, the action deciding residential location is not onlyexact but also random. Although we have obtained the same distribution law withthe exact action when the selection of residential location is seen as particle'smovement, but the meaning is different completely. The system move at nonlinearzone that is far away equilibrium state in Langevin equation's evolution by time,and there exists complex action of bifurcation. It has explained completely thecomplexity of urban habitants' distribution and the diversity of evolving result.(4)Research on habitant trip distribution.Reorganization of urban habitant bring the redistribution of urban population.The change must upset the original developing system made up of urban andtransportation that kept stable and harmonious. We will search for the tripdistribution status after habitant reorganization in the city to make the unstablesituation resume the former balance. Then we can provide exactly gist fortransportation programming that make city develop steadily. This part has putforward the simulating electron cloud and maximum information entropy modelon habitant trip distribution, and calibrated the models applying the data ofChangchun habitant trip .