Some of the reasons behind these patterns are thought of in terms of the area's site and its situation - two of the most important concepts in the study of urban geography.
SiteThe site is the actual location of a settlement on the earth and is composed of the physical characteristics of the landscape specific to the area. Site factors include things like landforms (i.e. is the area protected by mountains or is there a natural harbor present?), climate, vegetation types, availability of water, soil quality, minerals, and even wildlife.
Historically, these factors led to the development of major cities worldwide. New York City, for example, is located where it is because of several site factors. As people arrived in North America from Europe, they began to settle in this area because it was a coastal location with a natural harbor. There was also an abundance of fresh water in the nearby Hudson River and small creeks as well as raw materials for building supplies. In addition, the nearby Appalachian and Catskill Mountains provided a barrier to movement inland.
The site of an area can also create challenges for its population and the small Himalayan nation of Bhutan is a good example of this. Located within the world's highest mountain range, the terrain of the country is extremely rugged and hard to get around. This, combined with the incredibly harsh climate in many areas of the country has made much of the population settle along rivers in the highlands just south of the Himalayas. In addition, only 2% of the land in the nation is arable (with much of it located in the highlands) making living in the country highly challenging.
SituationSituation is defined as the location of a place relative to its surroundings and other places. Factors included in an area's situation include the accessibility of the location, the extent of a place's connections with another, and how close an area may be to raw materials if they are not located specifically on the site.
Though its site has made living in the nation challenging, Bhutan's situation has allowed it to maintain its policies of isolation as well as its own highly separated and traditionally religious culture.
Because of its remote location in the Himalayas getting into the country is challenging and historically this has been beneficial because the mountains have been a form of protection. As such, the heartland of the nation has never been invaded. In addition, Bhutan now controls many of the most strategic mountain passes in the Himalayas including the only ones into and out of its territory, leading to its title as the "Mountain Fortress of the Gods."
Like an area's site however, its situation can also cause problems. For example Canada's Eastern Provinces of New Brunswick, Newfoundland and Labrador, Nova Scotia, and Prince Edward Island are some of that country's most economically downtrodden areas due in large part to their situations. These areas are isolated from the rest of Canada making manufacturing and the little agriculture possible too expensive. In addition, there are very few close natural resources (many are off the coast and due to maritime laws the government of Canada itself controls the resources) and many of the traditional fishing economies they did have are now crashing along with the fish populations.
The Importance of Site and Situation in Today's CitiesAs shown in the examples of New York City, Bhutan, and Canada's East coast, an area's site and situation play a significant role in its development both within its own boundaries and on a world stage. This has occurred throughout history and is part of the reason why places like London, Tokyo, New York City, and Los Angeles were able to grow into the prosperous cities that they are today.
As nations around the world continue to develop, their sites and situations will play a large role in whether or not they will be successful and though today's ease of transportation and new technologies such as the Internet are bringing nations closer together, the physical landscape of an area as well as its location in relation to its desired market will still play a large role in whether or not such areas will grow to become the next great world city.