SPATIAL communication IS A dynamic flow process from one ar to another. It is a general concept that may refer to the activity of humans such as intraurban commuters or intercontinental migrants, but may additionally refer to web traffic in goods such as raw materials or to operation of intangibles such together information.

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While the beginning of the term might be traced to French geographers that the early 20th century, Edward Ullman's as Spatial communication is normally cited together the seminal declare of the concept. In Ullman's conception there to be “three bases for spatial interaction” or an ext fundamentally, three factors for why points move: complementarity, transferability, and intervening opportunity.

Complementarity describes the existence of a demand or deficit at one location and also a supply or surplus at one more without which over there is no financial rationale for any kind of movement. A workplace such as a factory or office tower is an instance of a location with a demand for labor, if a residential ar provides a source that workers. A sawmill calls for logs, when a forest provides them. To it is adapted a an allegory from physics, complementarity is like a potential gradient through goods and human being flowing from a greater energy state, where they are in surplus, come a lower power state, whereby they are in deficit. Indigenous the kingdom of physical, wind is the flow of air in between complementary atmospheric zones: from a high-pressure cell to a low-pressure cell.


The security surplus-deficit connection is commodity-specific, and also if the deficit is specifically specified, the direction and distance of movement will depend on the location where there is a surplus of just that kind of good. Complementary relationships may be the inspiration for interaction between distant regions, such as the circulation of petroleum over countless miles from the MIDDLE east to Europe, and within regions, such together the flow of shoppers native residential neighborhoods to small convenience stores over a distance of less than a mile or two.

David Ricardo's classical economic concept of “comparative advantage” gives a relative measure of the degree of financial complementarity between two countries based on their chance costs. All other points being equal, one nation will violin goods to another nation when that can develop a unit quantity at a reduced relative cost than the importing nation. In a similar vein, john Dunning's eclectic concept of foreign direct investment predicts that foreign investment will take place when a for sure in one country has such a powerful “firm-specific advantage” the it have the right to overcome the barriers to entry in a foreign nation market in which there is a “location-specific advantage” in factor costs such together land, labor, or capital. Thus, foreign direct investment operation from regions with a excess of capital to regions with a resources deficit, creating the international ownership lineaments the make-up the multinational corporation.

Transferability describes the expense of overcoming distance measured in real economic terms of one of two people time or travel cost. The expense of overcoming street is known as the “friction the distance.” If the friction of distance is too great, interaction will no occur in spite of a complementary supply-demand relationship. Friction of distance counts on prevailing transport technology and the price that energy. In general, the friction of distance has lessened over time, which is the prime factor in globalization and the appearance of megacities. Daily commuter flows, for example, room always subject come a take trip time constraint; a couple hours is a typical maximum because that the one-way daily journey to work. High-value, low-weight products such as jewelry are imminently transferable and exported ~ above a global scale, when heavy, low-value items such as concrete blocks space usually used an extremely close to whereby they are produced.

Intervening opportunity is the 3rd basis for interaction although it frequently is thought about as the reason for a absence of interaction in between two complementary locations. Complementarity will just generate a circulation if there is no intervening, or closer, location. The circulation of goods that would certainly otherwise occur between two complementary locations might be diverted to a 3rd location if it to represent an intervening opportunity: a closer complementary different with a cheaper as whole cost of transportation.

However, Ullman listed that the trade-diverting effect of an intervening opportunity could eventually facilitate communication between much more distant complementary locations. In his example, the nearest (intervening) source that logs would justify building and construction of a brief logging railway native the mill to the forest source and when it to be harvested, the railway would certainly be extended to the following intervening opportunity and so on until it ultimately reached a an ext distant complementary location. Flows to the an ext distant safety location might never have actually been established had the transportation facilities not been built in a series that incremental extensions to a collection of intervening opportunities.

Important forms of spatial communication such as traffic flows and also migration might be predicted and explained based on an analogy through Newton's design of the gravitational attraction between celestial bodies. Assuming that there is no intervening opportunity, the degree of complementarity between any kind of two regions is proportional come the product that the populations of the origin and destination regions.

The concept of spatial interaction deserve to be traced to French geographers' notions the geographie de circulation, including both the movement of physical objects and the communication of intangible ideas. However its fullest advancement as the most fundamental of all geographic concepts came in the middle 1950s as the seminal donation of Ullman.

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Prior come Ullman, had been conceptualized as a method of describing the areal differentiation of sites. With the spatial communication concept, Ullman shifted attention to case as a second and equally important locational attribute. Areal differentiation emerged together the result of transportation and trade that permitted specialization in specific economic activities and concentrations of various social groups.