Research On Scale Structure Of Urban System In Gansu Province

Urban system is an important criterion for regional competition and regional division of labor,the rationality of its scale structure is directly related to the function of towns and the promotion of regional competitiveness.In recent years,with the acceleration of urbanization process,Gansu Province,as the golden section of the Silk Road,is facing the pressure of underdevelopment of urban system,unbalanced of scale structure,small scale and weak strength,etc.,which makes the administrative division be broken.Comprehensive consideration of the rationality of the urban system has become the research direction of urban construction and development,related planning and urbanization development and transformation.In view of this,this paper studies the evolution dynamic mechanism,spatial differentiation characteristics,evolution types and laws of the scale structure of urban system in Gansu Province.The evaluation of influencing factors and rationality has important reference significance.In this paper,the scale structure of urban system in Gansu Province is taken as the research object.First of all,it combs the theoretical basis of the research on scale structure,including the definition of core concept,the theory of rationality judgment,the dynamic mechanism of evolution and the construction of theoretical model.Secondly,with the help of urbanization,the panel data from 2001 to 2016 are selected to explain theevolution status and existing problems of scale structure.Then,the first law theory,Gini index theory and position order scale theory are used to measure the scale structure of urban system,and the three-dimensional diagnosis model is constructed from three dimensions: scale distribution,scale compactness and scale efficiency.The spatial division of scale structure is explored.The different characteristics and evolution types summarize the evolution law of the rationality of scale structure.Finally,based on the multiple linear regression model,the effects of industrial structure,ecological environment,location conditions and urban functions on the evolution of scale structure are empirically analyzed.The results show that the symbiotic effect of institutional change,the adhesive effect of urban function,the coupling effect of industrial structure,the flexible effect of traffic location and ecological environment,the synergy of these four effects constitute the dynamic mechanism of the evolution of scale structure.The urban system as a whole shows the hierarchical evolution trend of the continuous expansion of the scale of each grade of cities and towns,the orderly growth of the low scale,and the phenomenon of scale grade faults in some regions,but the urban scale order is basically stable.The distribution of urban scale has fractal characteristics,the first role of the first city is weakening,the Gini index of economic scale is declining and the Gini index of population scale is stable.The temporal and spatial evolution characteristics of the threestages of development,which are medium reasonable,low reasonable and unreasonable,form the evolution types of optimal type,fluctuating type and inferior type,which show the evolution law of large "S" shape,which rises as a whole,fluctuates in short term and even decreases in interval.The industrial structure promotes the concentration of urban scale distribution,the ecological environment hinders the pace of population scale distribution and agglomeration,weakens the agglomeration force of economic and land scale distribution,and the traffic location suppresses the excessive concentration of urban scale distribution.The function of cities and towns aggravates the monopoly role of the first city.