Urban Planning Concepts: Metropolitan Areas, Gentrification, and Urban Sprawl
Metropolitan Area
A metropolitan area is an urban region consisting of a central city, which gives the area its name, and a series of satellite cities that may function as residential, industrial, commercial, and service centers, all organized in a centralized manner. The central city concentrates important functions that make it an organizing center of an extensive area encompassing several adjacent municipalities where the satellite cities are located.
In Spain, metropolitan areas do not have an official delimitation. In general, it is considered that the central city must have a minimum of 50,000 inhabitants, and the entire area, at least 200,000 inhabitants.
Suburban Area
A suburban area is a territory close to cities that, due to its characteristics, constitutes a transition zone between the urban core itself and the adjacent rural space. It forms the space of the urban periphery adjacent to the city, although it is part of it.
General Urban Planning Plan (PXOU)
The General Urban Planning Plan (PXOU) is the basic instrument for the integral planning of the territory of one or more municipalities. The plan projects urban development for a certain number of years, including land uses for each zone, land classification (urban, developable, and non-developable), buildability or building density, the road network, facilities, and environmental protection measures. Partial Plans specify the PXOU for each urban area, and Special Plans order specific aspects such as degraded areas or the old town.
Gentrification
Gentrification is a process of urban transformation in which the original population of a deteriorated sector or neighborhood with pauperism is progressively displaced by another with a higher purchasing power, which influences the renovation and remodeling of the neighborhood and the buildings. The term is a neologism that comes from the English “gentrification.” Gentrification begins when a group of people with a certain economic level discover a neighborhood that, despite being degraded and undercapitalized, offers a good relationship between quality and price and decide to settle in it. These neighborhoods are often located near the city center or have certain advantages, such as being located near employment centers, etc.
Urban Sprawl and Fragmentation
Most Spanish cities have elements from different periods: the historic center, the extensions, the open building, and the new peripheries. Cities are transformed by growing outwards with the creation of new residential spaces and areas of economic activity. Commercial centers, business parks, or housing estates appear. There is talk of a process of fragmentation of the urban space since it is presented as a set of spaces connected by motorways and roads. The Mediterranean city model has been replaced by the diffuse city type. The diffuse city extends horizontally and is separated into specialized and monofunctional areas:
- Residential areas
- Commercial areas
- Leisure areas
- Educational centers
This decreases human contact, exchanges, and sociability, leading to an urban typology characterized by the mix of uses and functions due to the tendency to occupy a very large territory.
Deterioration and Revitalization of Historic Centers
From the second half of the 20th century, the historic centers of many cities began to suffer progressive deterioration. Most of those who remained were the elderly with low incomes, so the center experienced a process of aging and impoverishment. All this was reflected in the urban deterioration because many houses were left empty. The previous trends were offset by revitalization processes. The historic center is beginning to be seen as an area of economic opportunities and also as a pleasant place to live. Many problems remain due to the aging of the population and the low level of income, combined with social marginalization and concentration.