Analysis Of The Spatial Form And Vitality Of Historical Urban Area

Since the founding of People’s Republic of China,especially since the reform and opening up,there has been unprecedented large-scale urban construction and renewal,which has significantly improved the quality of the living environment,but has brought unprecedented urban problems.Many historic cities in China are facing a double decay of physical form and social vitality.Specifically,there are significant problems of hollowing out,aging,poverty,old infrastructure,deterioration of living environment,and lack of public space in the historic city;at the same time,there are phenomena such as excessive tourism,red gentrification,and reduced recognition of places.The vitality of historic urban areas is the result of the isomorphism of the historic urban form and the social activities it carries.With the process of urban renewal,the original functional type and spatial pattern of the historic city can no longer meet the needs of modern life,and necessary adjustments must be made to meet the needs of residents and urban development under the premise of respecting the original urban history and culture.Numerous studies have shown that the organic renewal of urban form elements can significantly affect the distribution of spatial vitality.The historical urban areas of Qingdao and Dalian,which evolved from China’s modern "leasehold",have formed distinctive and unique historical landscapes.Due to the lack of systematic analysis of the spatial structure characteristics of the historic urban areas of Qingdao and Dalian in the past,there are problems such as inappropriate zoning,destruction of spatial texture,and damage to the authenticity and integrity of the historic urban areas,which in turn destroy the vital elements on which the historic urban areas are based.In recent years,China’s urban development pattern has been gradually changing from one of the most popular to one of the most popular.In recent years,China’s urban development model has gradually shifted from the extensible "incremental development" to the connotative "stock renewal".In the context of "stock regeneration",it has become an important issue to guide the stock regeneration of historical cities to reasonably and effectively measure and analyze the spatial vitality characteristics of historical urban areas,and to formulate regeneration planning strategies to improve spatial quality and reshape vitality spaces.At the same time,the advancement of "big data" era provides new means to reveal,analyze and solve urban complexity problems by using new spatial information technology and massive high-precision data.This thesis takes urban spatial vitality as the research content,and selects Qingdao and Dalian historical urban areas formed by the modern Lend-Lease cities as the research objects,and studies the inner spatial production mechanism and spatial vitality distribution characteristics of Qingdao and Dalian historical urban areas from two levels of theoretical research and empirical application.In the theoretical study,the theories and domestic and foreign research progresses related to urban spatial vitality and spatial production,as well as the history of urban development in the lease areas,are sorted out and summarized,the definition and components of urban spatial vitality are clarified,and the dual connotation of the internal generation mechanism and external representation of spatial vitality in the historic urban areas is determined.In the empirical study,the inner generation mechanism of urban spatial forms is first analyzed,namely,the planning characteristics and cultural inner association of colonialism in the recent leasehold.Drawing on Kevin Lynch’s urban imagery analysis,the thesis selects typical neighborhoods and controlling nodes established in the planning of Qingdao and Dalian concessions to represent the spatial centers of political power,religious power,police power and transportation power in the concessions,respectively,and analyzes the network centrality,line of sight control and spatial isolation of urban space.Afterwards,we used urban spatial morphology data and nighttime remote sensing light data to establish the basic data set for quantitative research on urban spatial vitality,and constructed the urban spatial vitality intensity index system and urban spatial morphology index system based on Jacobs’ urban vitality theory,analyzed the distribution characteristics of urban spatial vitality from urban scale,neighborhood scale and building node scale respectively,and conducted high and low clustering,and specifically divided The four main types of vitality distribution are classified,and the vitality renewal strategies are discussed according to different spatial vitality characteristics.The results of the study show that: 1)at the level of theoretical research,the internal historical mechanism of spatial vitality in the historical urban areas of the modern cities of the leasehold,represented by Qingdao and Dalian,is the "power-space" production mechanism;people and activities are the main body of spatial vitality and the external manifestation of urban spatial vitality,and nighttime The open source data such as remote sensing light data reflect the distribution characteristics and clustering characteristics of urban spatial vitality more accurately;the material spatial form,as the material carrier of people and activities,is the composition and influence element of urban spatial vitality,and the evaluation of urban spatial vitality based on Jacobs’ theory reflects the problem of regeneration of historical urban vitality faced in different urban contexts more realistically.2)The results of the spatial network analysis based on the power spatial characteristics of Qingdao and Dalian The results of the spatial characteristics of power in the historical urban areas show that colonial planning,as a technical means of authoritarian rule,has both coercive and scientific characteristics;the spatial form of the leasehold is influenced by the spatial network organization of power,and the power operation mechanisms such as class oppression,zoning segregation and social surveillance of the colonizers all constitute the deep structure of the urban spatial form to different degrees;the political,religious,police and transportation nodes of(3)At the level of the construction and analysis methods of the spatial vitality index system,the influence of physical space form on the composition of vitality mainly originates from six aspects: architectural functional diversity,road scale,architectural age diversity,concentration,accessibility and boundary vacuum elements.Among them,the indicators of building functional diversity and concentration have the most significant contribution to urban spatial vitality and are the primary spatial characteristics that affect the intensity of urban spatial vitality;the indicators of accessibility and boundary vacuum elements have a smaller contribution to urban spatial vitality and are the secondary spatial characteristics that affect the scale intensity of urban spatial vitality.4)The results of the spatial vitality analysis based on Arc GIS show that today’s cities spatial vitality elements are not only the product of specific urban texture or certain economic income level,but also the result of the interactive combination of different spatial form characteristics,i.e.more street activities and vitality are not singularly concentrated in the city center characterized by higher population density and mixed uses.The spatial vitality of the historic urban areas of Qingdao and Dalian both follow a polycentric spatial pattern,with different combinations of indicators of urban vitality distributed throughout the region.The cluster of high vitality values corresponds to the oldest historic city center area,which has the source of all vitality indicators.In the fringe zones away from the central city,medium and high potential vibrancy characteristics are similarly identified due to the topographically planned street patterns that create conditions for urban vibrancy.The medium and high vitality spaces are significantly separated by the multi-level road network and show regional differences;the low vitality spaces are clustered in the large port areas,green areas and hills in the urban fringe zone,and are mostly wedged into the overall vitality space in the form of holes.This thesis attempts to explore urban spatial vitality from the perspective of the interaction between people and space by using historical documents,spatial network analysis and big data statistics.Based on the historical planning characteristics,an explanatory framework of the spatial production mechanism of the modern leasehold is constructed,and the inner generation mechanism of spatial forms is quantitatively analyzed through spatial network analysis;quantitative evaluation indexes and methods of urban spatial vitality are established based on Jacobs’ theory,and the combination of different spatial elements affecting urban spatial vitality is unearthed.This thesis proposes a rational allocation and renewal of spatial vitality elements on the basis of respecting the structural characteristics of Qingdao’s urban space during the German-occupied period,the integrity of historical landscape features and historical information.The study helps planners to combine morphological features that are conducive to vibrant historic streets,historic urban environments and neighborhoods,thus promoting communities,local spatial practices and neighborhoods,and providing useful references for the preservation and organic renewal of historic urban areas.