Urban Development: Environmental and Socioeconomic Impacts
Urban Fringe: Industrial Sites, Facilities, and Residential Neighborhoods
The urban fringe forms a large area of nature strips or suburban surroundings of a city and its expansion. In this sector, we can distinguish three main areas:
- Large industrial sites, looking for very cheap land.
- Major facilities: supermarkets, leisure or sports centers, etc.
- Residential neighborhoods, which are basically of four types:
- Slums or shantytowns.
- Private housing developments: tower blocks and flats.
- Social housing.
- Areas with second homes or detached single-family homes.
The urban fringe has developed mainly during the twentieth century, and its growth has been directly related to immigration from rural areas. Its extension has been such in major cities that it has exceeded the natural obstacles presented by the territory and has encompassed smaller towns within it. This rapid and often uncontrolled urban growth is often called inorganic growth or “oil stain” growth. This denomination indicates that the city grows in a disconnected manner, and its peripheral nuclei start growing like a patch of oil until they join each other. This implies rapid growth and, in most cases, the loss of orthogonality of the expansion.
The positions in this sector of the city are rare. They already have similar functionality to that of the old city. On the contrary, its principal task is to serve as points from which to distribute the orders or increasing traffic in the city. Urban parks are the most characteristic aspect of the greenery. They are usually very large and their layout is irregular. They are located in more external areas of the city or peri-urban areas, like a green lung.
The peripheral area has two basic functions. It serves as a home base for most of the population in residential neighborhoods and is the place where the main industrial estates are located, as they need a lot of ground, which tends to be cheapest in this part of the city.
These peripheral areas are characterized by the presence of many interstitial spaces or vacancies. These are plots of land that have not been built because the previous buildings were demolished and have not yet been replaced, or because there is speculation on the land, waiting for a buyer to pay the price set by the seller.
Environmental and Socioeconomic Impacts of Cities
Cities generate a series of problems that can be summarized into two main categories: environmental and socioeconomic.
The most common environmental issues are:
- Deteriorating urban environment. Cities are characterized by a temperature higher than the surrounding rural areas due to the influence of factories, heating, traffic, etc. The temperature can be up to six degrees higher than the surrounding natural environment, increasing the need for water. It is necessary to refine the great quantity of wastewater generated, and it is common for large wastewater treatment plants (WWTP) to appear in the urban landscape.
- Increased air pollution. The air in cities is often very unhealthy. In Anglo-Saxon countries, this pollution and its harmful effects on the health of citizens, trees, plants, buildings, and monuments has been given the name “smog.”
- Disposal of urban waste. This is one of the major current issues. It requires heavy investments and technological development. There are two types:
- Sewage: Collected through the sewerage system and purified through treatment stations, causing serious problems of contamination and destruction of ecosystems.
- Solid waste: Primarily domestic waste, whose volume is constantly growing. Municipalities are responsible for this task, collecting it for treatment.
The environmental impacts have a clear relationship with social and economic issues. The most important are:
- Quality of life and urban planning. This is reflected in the following three issues:
- Generation of pathologies. The pace of life in cities causes anxiety or stress, nervous system disorders, aggression, etc. Pollution causes increased heart and lung diseases.
- Social exclusion and delinquency. Crime rates are higher in cities. This is related to the presence of certain social groups characterized by marginalization: drug addicts, vagrants, mafias, etc.
- Modification of demographic patterns. In cities, there is a clear reduction in the birth rate and an imbalance between population groups by sex and age. There is also a trend towards greater social isolation of individuals.
- Problems of traffic and circulation. These are reflected in the lack of parking, traffic jams, slow traffic, and deficient or incomplete operation of public transport. The solutions to these problems are the most difficult.
- Land speculation. The substantial differences in income among urban dwellers and the vast land price variability depending on the area cause clear segregation with very different levels of purchasing power. It is also quite high in areas with large avenues and shopping areas. The price will depend primarily on the demand.
Urban Morphology: Historic Center, Expansion, and Periphery
The different forms that cities present are influenced by several features, such as:
- The site of the city, the surrounding physical environment, and the topography on which it sits.
- The situation, that is, the geographical environment in general.
Morphology is the result of the combination of different types of plans: irregular or labyrinthine, radiocentric or circular, orthogonal or checkerboard. The construction of buildings also influences morphology, resulting in a distinct urban fabric and different types of built space. Finally, morphology depends on the uses to which urban land is intended, either for services, residential areas, or industrial areas.
Structure of the Urban Plan
From a historical and morphogenetic point of view, the urban plan can be divided into three major units: the historic old town center, the urban fringe or pericentral area, and the peri-urban or exterior expansion of the current city.
Historic Old Town Center
The historic center is the legacy of the pre-industrial city. It has an irregular, closed layout and various uses. This is the area of the city that in ancient times was surrounded by walls. It is characteristic of those settlements that developed during the Roman period, the Middle Ages, as well as in the times of the Renaissance and Baroque, up to the eighteenth century.
Its origin is usually associated with an early settlement or town that was located in an elevated area easy to defend or near water, either a watercourse or the sea. It tends to have a circular morphology, with narrow streets and the frequent presence of dead ends. It is characterized by poor internal communications and by the great difficulties it presents to vehicular traffic due to the narrowness and irregularity of the streets. City blocks are often irregular and of very different sizes and shapes. Squares are very numerous and in ancient times served as meeting places for markets, hawkers, shows, etc.
The historical center has no gardens, as ancient cities could not devote their limited interior space to this land use. They used to have some areas of indoor gardens to serve as a supply to the population if they had to withstand long sieges. Old towns are areas of services where administration and commerce currently dominate, especially small shops selling little bulky and light goods.
During the era of industrialization, the old town became denser, with buildings growing vertically, and some great avenues appeared inside. The area was segmented into quarters for the bourgeoisie, while others of much lower quality appeared for the working class.
In the 1960s, considerable destruction of much of the urban fabric took place, old buildings were replaced, and some areas were renovated for use by tertiary activities. This caused the saturation of both buildings and vehicle traffic, and also resulted in excessive internal segregation of space.
Since the mid-1970s, policies of integrated rehabilitation have been followed, through the granting of institutional support for the defense of traditional uses and the creation of many pedestrian streets. During these last decades, historical sites have suffered in many cases from urban policies aimed at the alignment of facades and the appearance of broad avenues that break the traditional irregular road network in these sectors.
Expansion and the Widening of the City
This area appeared after the demolition of the walls in the mid-nineteenth century. The growth of the city was generally conducted following a regular grid plan. Originally, it was characterized by low density in construction and the presence of bourgeois homes, but later it became denser due to vertical or height growth in order to satisfy certain tertiary functions.
The expansions have often been conditioned by the old layout of the walls, whose form has been adapted. On the other hand, they have been carried out in those places where the topography has allowed the extension of the city through areas with few obstacles to prevent their expansion. Its road network is characterized by orthogonality, but also by the emergence of the first-round belts. These are located along the circular contour of the walls, occupying the space left by them after demolition, or consolidating the road that once surrounded them.
City blocks usually have a sharp constructive monotony. This is due to the fact that, being planned for the first General Plan, it was decided to build on a similar model in most cases. Squares remained a fundamental element in the urban fabric. In this case, two types were constructed: the model of English squares with small gardens in the center, or continuing the legacy of Castilian town squares, a monumental building that is a great exponent of the new bourgeois mentality on the city.
In this area are the first large urban parks. The railway is a key element in this part of the city. But then this leads to serious problems, because the tracks become an obstacle if the city cannot easily overcome them, preventing normal urban growth and especially traffic. Cemeteries are another key element of the urban city in the nineteenth century.
Around the expansion in its suburbs, industrial areas began to emerge, as well as slums in the urban periphery. They were characterized by a diverse background with a closed, dense layout and low-quality housing. Also in this era of the late nineteenth century came the first landscaped neighborhoods, the so-called garden city, built mainly consisting of houses with green areas around them.
It is currently undergoing a process of transformation of obsolete industrial facilities and the replacement of old working-class districts with districts for the middle and upper-middle class.