② Urban internal form;
③ Evolution law of urban form. (Urban Planning Analysis)
The classical analysis of urban planning originated in Central Europe, and Germany's "morphogenesis" represented by Schlter, 1899) is its earliest theoretical basis. "Morphological gene" has been further developed in the works of M.R.G Kang Zeng (1960). Through the analysis of medieval towns in Europe, the planning and design elements are divided into streets and traffic networks composed of streets. Plots and blocks formed by them; And the building and its layout. By establishing and applying the following concepts and methods: planning unit, environmental cycle, environmental region, morphological framework, land redevelopment cycle and marginal zone. Among the above concepts and methods, "urban fringe" has the most extensive influence. This concept refers to the dynamic strip-shaped urban fringe composed of mixed land, and its existence is a common phenomenon in the historical development of cities and towns. The study of this "unstable" region is helpful to understand the development and evolution of cities and towns, and further provide suggestions for planning and management. Kang Zeen's contribution to the study of urban morphology can be summarized as five points: (1) The basic analysis system of urban planning was established; (2) It is the first time to use the whole process evolution method in English geographical documents; (3) Establish independent basic plots as research units; (4) Drawing a detailed map by using the research methods of field investigation and literature analysis; (5) Developed the concept of urban landscape (Whitehand, 1987). The Urban Morphology Research Group, established by the Department of Geography of Birmingham University in England from 65438 to the early 1980s, inherited and developed Kang Zeen's thoughts, and is one of the most active academic organizations in this field at present. In recent years, their influence has gradually expanded from the European urban morphology theory to the whole academic field of western urban research. Although the analysis and research of urban planning has developed many branches, such as the application of the principles of "planning control" and "development management", it is still of the most important significance to the practice of ancient city protection. (Theory of Urban Functional Structure)
There are two main branches of morphological theory formed in the United States: the first is Berkeley School, which appeared in the 1920s and is called the study of cultural morphology. Its main research object is residential area rather than city; The second is the Chicago School formed by the Sociology Department of the University of Chicago, which emphasizes the use of eclectic socio-economic theory to analyze urban land use. On the basis of the concentric circle theory founded by sociologist Burgess (1925), Huo Yite (1939) developed the sector theory, and Harris (1925) and You Man (1945) developed the multi-core city theory. After the 1950s and 1960s, the research on them and their followers had a wide influence in the world. As a part of the study of urban form, the theory of urban functional structure focuses on urban land, while planning and architectural design are only the carriers of urban land. In addition, compared with the theory of urban functional structure that explains the distribution of different functions in cities, Crystal's "central place theory" analyzes the spatial and scale relationship between cities. The theory of urban functional structure embodies the urban morphology method to study the relationship between urban land development from the perspective of social economics. (political and economic analysis)
The concept of political economy here broadly includes methods of macroeconomics, sociology and political science.
The method of political economy establishes the connection between the building environment and the commodity production process. Harvey, 1985), a representative scholar in this field, analyzed the contradictory relationship between the formation and change of urban landscape and the driving force of capitalist development, and established the theory of "capital loop" on this basis. He pointed out that the process of urban landscape change includes the fact of capital replacement. Ball, 1986) put forward this idea and developed the "building clause structure" model. He discussed the relevant social factors in the process of building production, including the dynamic role of developers, planning management and service objects and their relationships. Furthermore, Knox, 199 1+0) pointed out in the study that "building supply structure" covers a wider range. Through the analysis of American urban landscape, Knox proved that social and cultural factors are as important as economic factors, which affect the formation process of urban environment. The method of political economy emphasizes that the emergence and change of the built environment are closely related to the process of social production and reproduction, in which capital is the main factor, and the organizational form of urban development and the role played by relevant social institutions are also the focus of research (Wu, 1998). (Environmental Behavior Research)
Joel (Gehl, 2000), Lynch (Lynch, 1958), rapoport (Rapoport, 1990) and Wright (Witt, 1980) all established the theory of the relationship between human behavior and physical environment. Their explorations include how humans perceive specific environments and produce behavioral responses. In these studies, objective and scientific methods have replaced the old tradition of personal intuitive behavior research, and their theoretical works have changed the education and working methods of modern planning and design. In Lynch's series of studies, the method of "mental map" is used to reflect the individual's perception of the environment, and the psychological trend of the environment is analyzed with "node", "path", "landmark" and "region" as basic elements. At the same time, he used "identifiability" to describe environmental characteristics. The good building environment makes residents feel comfortable and cordial. Lynch emphasized that a good urban form should also include a series of elements: vitality and diversity (including biology and ecology), accessibility of transportation (open space, social services and work), controllability (space volume close to human body), sensation (identifiability), flexibility and social equality. Rapoport, 1990), Lozano, 1990) and Trancik, 1986) discussed people's behavioral responses to specific built environments, and analyzed that most modern urban problems are caused by "anti-city" and "anti-people" forces. Based on this point of view, they put forward that the development and evolution of the city should adapt to the local lifestyle and cultural needs, and stressed that the design should be coordinated with the environment, that is, the method of "environmental behavior". (building method)
In a large number of morphological theoretical studies, a series of methods developed by architects and urban designers provide a unique perspective for understanding urban morphology, among which typology and context studies are the most prominent. Typology originated in Italy and France, and Italian architects Mara Tori, caniggia and Rossi laid the foundation of typology. Rossi, 1982) thinks that genre is universal, it exists in all architectural fields, and genre is also a cultural factor, so it can be widely used in architectural and urban analysis. Because typology focuses on the classification of architecture and open space, it explains the urban form and hints at the future development direction. Typology has been widely used in European architectural design and urban landscape management. The focus of context research is to analyze the natural and humanistic characteristics of the material environment, with the aim of creating meaningful environmental space under different regional conditions. Context is studied in Appleyard, 198 1+0), Cullen, 196 1+0), crell (Krier, 1984), Luo (Rowe,/kloc). One of the most influential concepts is Karen's "urban landscape", which is based on two assumptions. One is that people's feelings about objective things can be recognized, and the other is that these laws can be applied to organize urban landscape elements, thus affecting people's feelings. By analyzing "serialvision", "place" and "content". Callen pointed out that in the 1960s (1950, 1960), Britain's large-scale urban renewal and construction of "creating brand-new, modern and perfect" was more valuable than the urban texture with multiple characteristics (including color, texture, scale and personality) and was worth promoting. This idea also has a profound enlightening effect on the reality of the rapid development of China city after the reform and opening up. (Research on Spatial Morphology)
According to this theory, cities are composed of basic spatial elements, which constitute different open spaces, closed spaces and various traffic corridors. The study of spatial morphology analyzes the basic geometrical features of a city from different scales, aiming at describing and quantifying these basic elements and their relationships. The study of spatial form originated from the "Research Center of Urban Form and Land Use" founded by March and Martin (1972) of Cambridge University in England. Subsequently, various concepts were developed to define and describe buildings and residential settlements (Steadman, 1983: Mitchell, 1990), among which "spatial syntax" was the most influential, which can be defined as a technical method to describe, explain and quantify the spatial structure of buildings or settlements. This method not only emphasizes the analysis of the geometric characteristics of spatial sets, but also contains social and anthropological significance (Hillier, 1983).
The urban morphology theory discussed above provides a series of methods to analyze the urban physical environment. Although they overlap, according to different research objects and methods, related theories can be classified into three categories: (compact city or new traditional development) and traffic demand management, which requires creating high building density, mixed land use, developing pedestrian and public transportation systems and a series of new design principles. As a material reference, urban form is an important part of planning research such as "sustainable development" and "urban traffic", and more perfect and reasonable urban form research should be paid full attention to. The significance of urban morphology research lies in its relationship with urban design. Although the concept of urban design has not formed a comprehensive consensus definition for more than 30 years, the understanding of urban design as an independent discipline in practice can be described as the joint participation of architecture, urban planning and landscape architecture, which endows the environment with a specific form of activity. Among them, activity refers to creating new structural elements by using existing conditions to improve the urban environment that lacks unity and integrity (Schurch, 1999). The goal of urban form is to understand the relationship between the formation process of urban structure and cultural, socio-economic and political forces. The isomorphic relationship between urban form and urban design is not only reflected in the text description, but also in the design practice, so the systematic study of urban form can be used to strengthen and integrate the theoretical basis of urban design.