Try to summarize and discuss the development and evolution of western urban planning theory from modern times to 1950s.

★ The development and evolution of western urban planning theory from modern times to 1950s;

18th century, after the industrial revolution, the spatial environment and material form of modern western cities have undergone profound changes. The industrial revolution has led to the worldwide urbanization, and the concentration of a large number of people in cities has promoted the continuous expansion of urban scale, resulting in urban housing, employment, environment and other problems. At the same time, the revolutionary development of modern urban functions and the application of new transportation and communication tools have greatly changed the physical environment and spatial scale of modern cities, and urban society has a greater degree of openness. The speed of urban spontaneous diffusion and growth is beyond people's expectation, and it is beyond people's ability to control by conventional means. In order to solve these contradictions, planners choose to find solutions from different angles and put forward various urban planning ideas and theories.

1. "Garden City" Theory

1898 British Howard put forward the theory of "garden city". In his book Tomorrow-The Road to Peace for Real Reform, he proposed that "the city should be combined with the countryside" and elaborated his theory in detail with a diagram of "garden city". The planned population is 32,000, with an area of 404.7㎡. The urban area is composed of a series of concentric circles and six radiation lines, with 20hm2 park as the center, followed by public buildings, parks, shops, schools and houses. There are 2033.4 hm2 of agricultural and animal husbandry land on the outskirts of the city. He regarded the city as a whole, connected with the relationship between urban and rural areas, and put forward the views of population density, urban economy and urban greening, which played an important role in the establishment of modern urban planning discipline.

Howard believes that the deterioration of urban environment is caused by urban expansion, and the infinite expansion of cities and land speculation are the root causes of urban disasters. He suggested limiting the spontaneous expansion of the city and making the urban land belong to the unified organization of the city; The excessive concentration of urban population is due to the "magnetic force" that attracts population concentration. If the "magnetism" of the city can be controlled and transplanted consciously, the city will not expand blindly. The combination form of "urban-rural", that is, garden city, has both the advantages of urban and rural areas, but has no disadvantages of both.

Therefore, Howard's garden city includes two parts: the city and the country. The city is surrounded by agricultural land; Urban residents often get the supply of fresh agricultural products nearby; There is a nearby market for agricultural products, but the market is not limited to the local area. Residents of rural cities live and work here. All land belongs to all residents collectively, and rent must be paid for the use of land. All the income of the city comes from rent; The value-added gained from construction and settlement on the land is still owned by the collective. It is necessary to limit the size of the city so that every household can get close to the rural natural space very conveniently.

The meaning of garden city:

Garden city is a city designed for health, life and industry. Its scale can provide rich social life, but it should not exceed this level. There should be a permanent agricultural belt around, and the land in the city should be owned by the public and entrusted by a Committee.

The influence of garden city:

In view of the urban problems in modern society, Howard put forward a groundbreaking planning idea; It puts forward a series of original opinions on urban planning issues such as urban scale, layout structure, population density and green belt, and is a relatively complete urban planning ideological system. Garden city theory has played an important role in enlightening modern urban planning thoughts, and has had a great influence on some later urban planning theories, such as "organic evacuation" theory and satellite city theory. After the 1940s, Howard's thoughts were also reflected in some important urban planning schemes and urban planning laws and regulations.

2. Athens Charter and Machu Picchu Declaration

1922, Corbusier wrote the book "The City of Tomorrow" and put forward the renovation plan of Paris. It advocates reducing the building density in the city center and increasing the population density. Buildings develop to high-rise buildings, increase the width of roads and open spaces and green spaces on both sides, and boldly change the traditional structural layout of big cities.

1933, the International Association of Modern Architecture (CIAM) held a meeting in Athens and formulated the Outline of Urban Planning, which was later called the Athens Charter. The Outline first proposes that the city and its surrounding areas should be studied as a whole, and the purpose of urban planning is to solve the normal operation of the four major activities of living, work, entertainment and transportation.

1977 65438+In February, a group of famous architects and planners gathered in Lima, Peru, to evaluate the practice of the Athens Charter. They think that some principles of the Athens Charter are correct, but they think that their planning pursues the method of functional zoning, ignoring the various connections between people in the city, and should create a comprehensive and multifunctional living environment. After the meeting, the Machu Picchu Declaration was published, which also raised the issue of harmony between living environment and natural environment.

Frenchman le corbusier boldly introduced the concept of industrialization into urban planning. He put forward the theory of "bright city" to describe the advanced state of urban life. The theory of "bright city" advocates transforming the city with a brand-new planning concept, and envisages building high-rise buildings, modern transportation networks and large green spaces in the city to create a sunny modern living environment for mankind. He believes that the main problem of big cities is that the population density in the center of the city is too high. Urban mobile traffic is increasingly developed, the number is increasing and the speed is getting faster and faster, but the existing urban road system and planning methods conflict with this requirement; There are too few urban green spaces, and the conditions of sunshine ventilation and leisure sports are too poor. Therefore, we should focus on planning and improve the existing space of the city through technical means to adapt to this situation. He advocated improving the building height in the central area of the city, thinking about high-rise development and increasing population density. He also believes that the traffic problem is caused by the increase of vehicles, and the road area is limited. The closer to the city center, the more concentrated the traffic, while the city develops from the inside out. The closer to the city center, the narrower the road. He advocates that there should be more central open space and green space, and increase the width of roads and parking lots, as well as the direct connection between vehicles and houses, reduce street intersections or organize layered three-dimensional traffic.

The Machu Picchu Charter signed in 1977 reexamines the thought of functional rationalism, promotes social culture, and emphasizes that material space is only one aspect that affects urban life, and the decisive factors should be urban culture, social communication and political structure, thus giving more consideration to the cultural function and "humanistic care" of the city and proposing "preservation and protection of cultural relics and historical heritage".

It took 44 years from the Athens Charter to the Machu Picchu Charter. In this process, urban planning has gradually changed from the functional rational thought of paying attention to material form planning to the concept of paying attention to urban humanities and ecological functions. The implementation of the plan should be able to adapt to the constant changes of urban material and culture. Every specific city and region should formulate standards and policies suitable for its own characteristics, create suitable living space for people, and pursue the unity of architecture, city and landscaping.

3. Neighborhood units and community planning

In 1930s, the United States and Europe put forward the theory of "neighborhood units". "Neighborhood unit" is the basic unit of the residential area. Primary schools are set up in the residential area so that children do not have to cross the road to go to school, thus controlling and calculating the population utilization scale. Later, I considered the public facilities needed for daily life. After World War II, Europe developed into the theory of "community planning". Generally, the residential area is divided into ten traffic lanes, which becomes the basic unit of the residential area. Residential buildings, public buildings and green spaces are comprehensively arranged, and general living services can be solved in residential areas.

4. Organic evacuation theory

In order to solve the "urban disease" caused by urban expansion, Eli saarinen put forward the theory of organic evacuation in the book "City-Its Development, Decline and Future" published in 1934. Inspired by the phenomenon of cell growth of biological organisms, he believes that the expanded urban area can be divided into areas used by different concentration points and areas needed for different activities. He changed disorderly concentration into orderly dispersion, divided dense areas into market towns or regions, separated by green belts, and let urban residents get close to nature.

The theory of "organic evacuation" is a theory of urban development and layout structure put forward by Finnish architect E. Sha Lining to alleviate the disadvantages caused by excessive concentration of cities.

Sha Lining systematically expounded the theory of organic evacuation in his book City, Its Growth, Decline and Future written in 1942. He believes that today's declining cities need revolutionary evolution based on reasonable urban planning principles, so that cities have a good structure and are conducive to healthy development. Sha Lining put forward the viewpoint of urban structure of organic evacuation. He believes that this structure should not only conform to the essence of human habitation, but also facilitate people to live a harmonious social life and feel the pulse of the city without being divorced from nature.

The urban development mode of organic evacuation can make people live in an environment with both urban and rural advantages. Sha Lining believes that as an organism, the internal order of a city is actually consistent with a living organism. If part of the order in the body is destroyed, it will lead to paralysis and necrosis. In order to save today's city from decline, it is necessary to completely renew the city materially and spiritually. We can't let the city condense into messy blocks any more, but we should distribute the population and jobs in the city to areas far from the center for rational development according to the functional needs of organisms. Organic evacuation theory holds that there is no reason to arrange heavy industry in the city center, and light industry should also be evacuated. Of course, many businesses and urban administrative departments must be located in the center of the city. The large area of land vacated by the industrial relocation in the downtown area should be used not only to increase green space, but also for technicians, administrators and business people who have to work in the downtown area to enjoy family life nearby. A large number of businesses, especially the daily life supply departments crowded in the downtown area, will leave the crowded downtown area with the evacuation of the downtown area. Many families crowded in the downtown area will be evacuated to the new area, which will get a more suitable living environment. The population density in the central area will also decrease.

The two basic principles of organic evacuation are: the daily life and work of individuals, that is, the area called "daily activities" in Sha Lining, are arranged centrally; Where "accidental activities" are not frequent, they need not be confined to a certain location, but scattered. Daily activities should be concentrated in a certain range as far as possible, and the traffic required for activities should be reduced as much as possible. It is not necessary to use all mechanized means of transportation. It doesn't hurt to go back and forth to the occasional place, although the distance is long, because there are unobstructed traffic arteries in the peripheral green space of daily activities, so you can travel quickly at a higher speed.

According to the theory of organic evacuation, people should mainly walk in their daily lives and give full play to the role of modern means of transportation. This theory also holds that it is not the modern means of transportation that paralyzes the city, but the poor organization of urban functions, which forces people who work in the city to spend a lot of time and energy running back and forth every day, resulting in urban traffic congestion.

After the Second World War, the theory of organic evacuation has had an important impact on the process of building new cities, rebuilding old cities and even the evacuation and expansion of big cities to the suburbs in Europe and America. Since the 1970s, cities in some developed countries have been excessively evacuated and expanded, which has led to new problems such as increased energy consumption and the decline of old urban centers.

5. Regional planning theory

With the development of cities and the complexity of urban problems, people realize that we can't talk about cities as a unit, but we must study social, economic, resources, transportation and other aspects from the regional and geographical scope. From a regional perspective, the overall thinking and planning adjustment of social and economic development and productivity layout are carried out. Western regional planning theory developed from the late 20th century, and British Gajdys put forward the concepts of cluster cities and regional planning. Some countries in the United States and Europe implement economic zone planning, and big cities also study the region as an economic unit, social unit and urban system, and plan the metropolitan area.

(B) Review the evolution of urban planning concepts

Three schools of western modern urban planning;

1) with e? The planning thought of "Garden City" represented by ebenezer howard emphasizes the dispersion of cities. (pre-theory)

2) Eli? Le Corbusier, as the representative, advocates the planning idea of strengthening urban agglomeration by using advanced industrial technology. (function)

3) Ilir? With Sha Lining as the representative, it advocates the planning concept of following the law of urban development and implementing organic evacuation. (spirit)

(3) Development trend

After World War II, urban planning has made new progress. Urban planning has extended from architecture and engineering technology to humanities, which has become the result of multi-disciplinary integration and cross-participation.

In the future society, other trends will be more noticeable. First, in the face of capital globalization and the information age, local governments have become the main battlefield of planning work, and rigid administrative orders will be replaced by territorial scientific governance. Planners play a more important role in communication, coordination and compromise. Second, a mature civil society will be the main force to promote the transformation of the political system to openness, decentralization and transparency. Thirdly, looking at the history of modern urban planning for more than one hundred years, it has changed from a technical role of advocating scientific rationality to a role of organizing public opinions and coordinating different interest groups in public affairs.

(4) Conclusion

Urban planning depicts the grand blueprint of urban development, and the large-scale urbanization brought by the industrial revolution has brought unprecedented impact to the city, so people began to explore the road of urban development from different angles. From Utopia to Garden City, to the publication of Athens Charter and Machu Picchu Charter. In order to adapt to the development of the city, urban planning is constantly developing and improving.