The structural model of the North American city is in the tradition of the city models of the Chicago School and illustrates the essential social, economic and functional, but also ethnic characteristics of the North American city. It shows typical ring-zonal, sectoral and multi-core structures and illustrates the expansion and relocation of uses and population groups in the urban region.
Downtown is characterized by a checkerboard layout and the juxtaposition of residential areas from population groups that have very different socio-economic statuses, including homelessness. In addition to residential areas, it is functionally characterized by a mix of upscale service facilities and small industry. It has a well-developed transport infrastructure for rolling and stationary traffic. Processes of gentrification are an indicator of recent fringe-core shifts of the residential population to refurbished, newly built or redesigned residential areas within the downtown area.
In the urban structure model, a pronounced functional differentiation is made clear: in the form of district formation in the downtown area as well as in the form of residential areas, commercial areas and supply centers. Both the traditional industrial areas and the high-tech corridors are sector-oriented on main traffic axes. The spatial concentration of companies in office and business parks, which are distributed over the entire city area, is typical. This shows processes of the core-to-edge shift in both business and living. The dominance of private transport – which contributes significantly to an extreme expansion of the urban area with a dense network of motorways – is clearly recognizable as a feature of North American cities.
What is not explicitly described in the structural model is the fact that the choice of where to live is influenced by certain factors, for example land and property prices, the image of a district and the desire for social and ethnic homogeneity. The gated communities – mostly located in the urban outskirts – are to be read as an indicator for the increasing social disparities and also for an increasing privatization of the cities.
It is also not explicitly shown that the edge cities as urban workplaces and supply centers in urban areas can cause the central business district to lose importance and can increase the urban sprawl of the areas on the edge of the metropolitan areas (urban sprawl).
Bakken Formation, North Dakota – fracking
The Bakken Formation is a geological unit in North Dakota that extends over an area of approximately 500,000 square kilometers; this corresponds to 1.5 times the area of Germany. The map shows a small section of this area of around 60 km × 50 km. This can be located, for example, using the small town of Williston or the Sakakawea reservoir on the Missouri.
The dynamism of economic development in the region becomes clear when one compares the population of Williston in the 2010 Census with estimates for 2013. Within a few years, the population grew by 42 percent from 14,700 to 20,900. In the same period, the population of Watford City almost doubled from 1,700 to 3,300. The cause of the development is the boom in fracking in the region, which creates jobs for the numerous people who have moved there and offers good earning potential.
The region’s economy was originally based on agriculture in the northern Great Plains, with the cultivation of spring wheat and extensive grazing dominating. A geographical peculiarity resulted from the location on the Missouri. Near Williston, Lake Sakakawea changes into an alluvial landscape with swamps and alluvial forests, the character of which is determined by fluctuations in the water balance.
Today the area is covered by a large number of wells that produce oil. The model shows the principle. The term fracking stands for “hydraulic fractioning”. It enables the extraction of crude oil that is diffusely distributed and embedded in the storage rock. For this purpose, a mixture of water, sand-ceramic particles and chemicals, the so-called fracking fluid, is pressed into the storage rock at high pressure. Cracks form there. The petroleum it contains mixes with the fracking fluid and flows back to the surface of the earth, where it is separated from the fracking fluid. Furthermore, the crude oil is transported away and processed like conventionally extracted crude oil. The USA has strongly advanced the oil production with fracking, on the one hand,
The chemicals used in fracking are one of the biggest criticisms. They are used, for example, as corrosion protection, lubricants and liquefaction aids. Critics fear, for example, pollution of the groundwater, which is necessary for supplying the population or for irrigated agriculture. Should poisons get into the groundwater, such damage could hardly be remedied. Another point of criticism is the high water requirement for fracking. This is a problem especially in arid areas.
Although fracking has only been practiced as a production method for a few years, a temporal and spatial change is already evident in the Williston area. In the east and west are areas in which numerous wells have already been exhausted and shut down. New boreholes are mainly in the central subspace. There is no active drilling in the prairie and wildlife sanctuaries south of Lake Sakakawea. However, these areas are surrounded by drilling sites and there are some idle wells in the protected areas.
Typical costs for the production of crude oil with fracking are between 30 and 85 US dollars per barrel. This explains why phases with low oil prices on the world market, such as 2014/2015, have a direct impact on production. If the price on the world market falls below the production costs for a long time, this becomes uneconomical.
While US oil production was 9 million barrels per day at the beginning of 2013, it was 7 million barrels at the end of 2013. During this period, the oil price began to fall from its 2011/2012 high, but had not yet reached its 2014/2015 low. In 2014, around a quarter of the drilling rigs came to a standstill. They are used to carry out the first and most expensive work step in fracking, drilling into the rock layers. The development of oil prices on the world market will therefore be decisive for the future of fracking in North Dakota.