2. Suburbanization or suburbanization, referred to as suburbanization. This is a decentralized process in which population, employment and service industries move from the center of a big city to the suburbs. The so-called suburb refers to the adjacent area outside the administrative boundary of the central city, mainly the urban edge outside the core of the urbanized area. Suburbanization includes three kinds of emigration: one is population emigration, which is mainly caused by the huge population pressure in the city center and the adverse impact of this pressure on the living environment. Second, industrial relocation, mainly because there is a large area of low-cost land outside the city center, which can better allocate transportation facilities such as railways, ports and highways. Thirdly, the retail industry moves out, which is a measure that the downtown business is forced to take in the face of fierce competition from suburban businesses after the population and industry move out. Suburbanization does not mean the decline of big cities, but the transformation of cities from high-density concentration to low-density expansion. In this transformation, the built-up area is expanding and the urban population is increasing.
3. As a phenomenon of higher education, "University Town" first appeared in some countries with developed higher education, such as Britain and America. It usually refers to the continuous expansion of the university's own scale in the process of university development. Some universities gather together, and the surrounding university or university campus itself becomes a town with a certain scale, which is usually called "University Town".
The Education Dictionary interprets "University Town" as a community built around universities. The population is generally 500-65438+million, which provides a good learning environment and convenient accommodation, transportation and other conditions for college students. Such as Polonia in Italy, Cambridge and Oxford in Britain, Tsukuba in Japan, etc. The function of the university town is mainly to provide social security for the university's infrastructure and logistics system, and attract universities to run schools in the city through certain mechanisms. There are two main ways to form foreign university towns: one is naturally formed, such as Boston in the United States, Oxford and Cambridge in the United Kingdom, which are naturally formed after more than 100 years of history; The other is active construction, such as Missouri in the United States and Tsukuba University Town in Japan, which was jointly built by the state, local governments, universities and enterprises with the rapid development of higher education after World War II.
4. Central Business District (CBD) refers to the area where the main business activities are carried out in a country or a big city. Its concept first appeared in the United States of 1923, and was defined as "business gathering place" at that time. Subsequently, the connotation of CBD has been continuously enriched, and it has become the economic development center of a city, a region and even a country. Generally speaking, CBD highly concentrates the city's economic, technological and cultural forces. As the core of the city, it should have many functions such as finance, trade, service, exhibition and consultation, and be equipped with perfect municipal transportation and communication conditions. The more famous CBD cities in the world are Manhattan, new york, City of London, La Defense, Shinjuku, Tokyo, Central, Hong Kong and so on.
CBD is the business card of an international metropolis, which has a strong cross-regional and even transnational economic radiation, such as new york Manhattan, the City of London, La Defense, Tokyo Shinjuku, Hong Kong Central and Shenzhen Futian CBD. The central business district is the symbol and symbol of urban modernization, the functional core of the city, and the dense area of urban economy, science and technology and culture, which is generally located in the golden zone of the city. A large number of financial, commercial, cultural, service and a large number of business offices, hotels, apartments and other facilities have been concentrated. It has the most perfect modern infrastructure such as transportation and communication and a good environment, and a large number of companies, financial institutions and enterprise consortia carry out various business activities here. For example, there is a commercial center in Sydney, and the commercial centers in Hong Kong are in Central and Tsim Sha Tsui. The United States and Canada call the central business district "urban business district", because in the past, residential areas were all on the mountain, while shopping streets were all under the mountain. Japan and South Korea call CBD "capital" or "busy street". CBD is mostly located in the main core area of a country or region, where there are all kinds of first-class buildings and perfect public facilities, such as Grade A commercial buildings, shopping malls, government and public institutions, entertainment facilities and so on. In addition, the traffic accessibility in this area is extremely high, and expressway, railways, ports and airports are all located in convenient locations around this area, making it extremely convenient for citizens to travel between regions. CBD generally covers an area of 3 to 5 square kilometers, and some are even larger, with a total construction area ranging from five to six million square meters to tens of millions of square meters. CBD is not only the functional core of a city, but also an important symbol of a modern metropolis, and its central land price is often much higher than that of the surrounding areas of CBD. CBD highly concentrates the city's economic, technological and cultural forces, and has many functions such as finance, trade, service, exhibition and consultation. The specific function of CBD requires that the buildings in this area must be high-density and modern. Therefore, CBD has gathered many magnificent and patchwork super high-rise buildings, and has very convenient transportation, modern information exchange system and a large number of office, catering, service and accommodation facilities. Generally speaking, offices account for 50% of the total construction area, commercial, catering and commercial-residential buildings account for about 40%, and other service facilities and necessary supporting facilities account for about 10%.