Urban geography is a branch of human geography concerned with various aspects of cities.
location and space
spatial processes that create patterns observed in urban areas.
the site, evolution and growth, and classification of villages, towns and cities
their location and importance in relation to different regions and cities.
Economic, political and social aspects within cities are also important in urban geography
a concentration of people
with a similar way of life based on job type, cultural preferences, political views and lifestyle.
Specialized land uses, a variety different institutions and use of resources also help in distinguishing one city from another.
In addition, urban geographers also work to differentiate areas of different sizes.
Two major themes that dominate its study today.
The first of these is the study of problems relating to the spatial distribution of cities and the patterns of movement and links that connect them across space. This approach focuses on the city system.
The second theme in urban geography today is the study of patterns of distribution and interaction of people and businesses within cities. This theme mainly looks at a city's inner structure and therefore focuses on the city as a system.
Different levels of analysis. In focusing on the city system, urban geographers must look at the city:
on the neighborhood
citywide level,
as well as how it relates to other cities on a regional, national and global level..
Central place theory is a spatial theory in urban geography that attempts to explain the reasons behind the distribution patterns, size, and number of cities and towns around the world. It also attempts to provide a framework by which those areas can be studied both for historic reasons and for the locational patterns of areas today.
The theory was first developed by the German geographer Walter Christaller in 1933 after he began to recognize the economic relationships between cities and their hinterlands (areas farther away). He mainly tested the theory in Southern Germany and came to the conclusion that people gather together in cities to share goods and ideas and that they exist for purely economic reasons.
Before testing his theory however, Christaller had to first define the central place. In keeping with his economic focus, he came to the conclusion that the central place exists primarily to provide goods and services to its surrounding population. The city is in essence, a distribution center.
To focus on the economic aspects of his theory, Christaller had to create a set of assumptions. He decided for example that the countryside in the areas he was studying would be flat, so no barriers would exist to impede people's movement across it. In addition, two assumptions were made about human behavior: 1) Christaller stated that humans will always purchase goods from the closest place that offers the good, and
whenever demand for a certain good is high, it will be offered in close proximity to the population. When demand drops, so too does the availability of the good.
In addition, the threshold is an important concept in Christaller's study. This is the minimum number of people needed for a central place business or activity to remain active and prosperous.
This then brings in the idea of low-order and high-order goods. Low-order goods are things that are replenished frequently such as food and other routine household items. Because these items are purchased regularly, small businesses in small towns can survive because people will buy frequently at the closer locations instead of going into the city.
High-order goods though are specialized items such as automobiles, furniture, fine jewelry, and household appliances that are bought less often. Because they require a large threshold and people do not purchase them regularly, many businesses selling these items cannot survive in areas where the population is small. Therefore, they often locate in large cities that can serve a large population in the surrounding hinterland.
Within the central place system, there are five sizes of communities. A hamlet is the smallest and is a rural community which is too small to be considered a village. Cape Dorset (population 1200), located in Canada's Nunavut Territory is an example of a hamlet. The rank order of central places is:
Hamlet
Village
Town
City
Regional Capital
Examples of regional capitals would include Paris, France or Los Angeles, California. These cities provide the highest order goods possible and have a huge hinterland.
If visually imagined, the central place is located at the vertexes (points) of equilateral triangles. They then serve the evenly distributed consumers who are closest to the central place. As the vertexes connect, they form a series of hexagons- the traditional shape in many central place models.
This shape is ideal because it allows the triangles formed by the central place vertexes to connect and it represents the assumption that consumers will visit the closest place offering the good.
In addition, the central place theory has three orders or principles. The first is the marketing principle and it is shown as K=3 (K is a constant). In this system, market areas at a certain level of the central place hierarchy are three times bigger than the next lowest one. The different levels then follow a progression of threes, meaning that as one moves through the order of places, the number of the next level goes up three times. For example, when there are two cities, there would be six towns, 18 villages, and 54 hamlets.
There is also the transportation principle (K=4) where areas in the central place hierarchy are four times bigger than the area in the next lowest order. Finally, the administrative principle (K=7) is the last system and here, the variation between the lowest orders and highest orders increase by a factor of seven. Here, the
highest order trade area completely covers that of the lowest order, meaning that market serves a larger area.
In 1954, German economist August Losch modified Christaller's central place theory because he believed it was too rigid. He thought that Christaller's model led to patterns where the distribution of goods and the accumulation of profits were based entirely on location. He instead focused on maximizing consumer welfare and creating an ideal consumer landscape where the need to travel for any good was minimized and profits were held level, not maximized to accrue extra.
A country's leading city is always disproportionately large and exceptionally expressive of national capacity and feeling. The primate city is commonly at least twice as large as the next largest city and more than twice as significant. - Mark Jefferson, 1939
Geographer Mark Jefferson developed the law of the primate city to explain the phenomenon of huge cities that capture such a large proportion of a country's population as well as its economic activity. These primate cities are often, but not always, the capital cities of a country. An excellent example of a primate city is Paris, which truly represents and serves as the focus of France.
They dominate the country in influence and are the national focal-point. Their sheer size and activity becomes a strong pull factor, bringing additional residents to the city and causing the primate city to become even larger and more disproportional to smaller cities in the country. However, not every country has a primate city, as you'll see from the list below.
Some scholars define a primate city as one that is larger than the combined populations of the second and third ranked cities in a country. This definition does not represent true primacy, however, as the size of the first ranked city is not disproportionate to the second.
The law can be applied to smaller regions as well. For example, California's primate city is Los Angeles, with a metropolitan area population of 16 million, which is more than double the San Francisco metropolitan area of 7 million. Even counties can be examined with regard to the Law of the Primate City.
Paris (9.6 million) is definitely the focus of France while Marseilles has a population of 1.3 million.
Similarly, the United Kingdom has London as its primate city (7 million) while the second largest city, Birmingham, is home to a mere one million people.
Mexico City, Mexico (8.6 million) outshines Guadalajara (1.6 million).
A huge dichotomy exists between Bangkok (7.5 million) and Thailand's second city, Nanthaburi (481,000).
India's most populous city is Mumbai (formerly Bombay) with 16 million; second is Kolkata (formerly Calcutta) with more than 13 million; and third is less than 13 million.
China, Canada, Australia, and Brazil are additional examples of non-primate-city countries.
Utilizing the metropolitan area population of urban areas in the United States, we find that the
U.S. lacks a true primate city. With the New York City metropolitan area population at approximately 21 million, second ranked Los Angeles at 16 million, and even third ranked Chicago at 9 million, America lacks a primate city.
In 1949, George Zipf devised his theory of rank-size rule to explain the size cities in a country. He explained that the second and subsequently smaller cities should represent a proportion of the largest city. For example, if the largest city in a country contained one million citizens, Zipf stated that the second city
would contain one-half as many as the first, or 500,000. The third would contain one-third or 333,333, the fourth would be home to one-quarter or 250,000, and so on, with the rank of the city representing the denominator in the fraction.
While some countries' urban hierarchy somewhat fits into Zipf's scheme, later geographers argued that his model should be seen as a probability model and that deviations are to be expected.