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Geographical Models

Before treating computer graphics and geographical information systems (GIS), which purists consider only tools, mention should be made of the criticism of academic geography as being mere description, with a lack of theories. Traditionalists would argue that all places on the Earth are different, that therefore description of these variations represents reality, and that geographers need only address themselves to the "real" world. These practitioners often reject models, two of the most successful of which in geography have been Central Place Theory in human geography, and the Köppen system of world climates in physical geography, which are examined, as examples, below.

Central Place Theory arose from studies of the distribution of settlements in the eighteenth century in Germany where it was postulated that places of varying size and function on a "uniform plain" would be arranged in hexagonal hierarchies. This has proved to be essentially the case, for example, on the delta of the Nile in Egypt, and elsewhere, as demonstrated by cartography and remote sensing. An elaboration of this is in the location of functional areas within cities, as exemplified by the case of Chicago. However, critics have observed that both concentric and sector patterns are evident in Chicago and that what obtains in a relatively modern city in the American Midwest does not necessarily apply to European and especially Asian cities. Chicago, with its location on the shores of one of the Great Lakes, is unique because of its special geographical setting and other factors.

More successful has been the Köppen system of climatic classification, which also had its origins in Europe, through the work of Wladimir Köppen (1846–1940) in the nineteenth and twentieth centuries. When long-term information was available from weather stations worldwide, it was observed that patterns were repeated in separate, but expected locations around the globe. Thus, to take one example, between approximately 30° and 40° latitude on the west coasts of all the continents, a Mediterranean climate was recognized. This climatic type is characterized by having high-sun (summer) drought and almost all of its precipitation in the low-sun (winter) months, the opposite of what would be expected. Thus in addition to the type example in Europe and the Middle East, it was found that California in the northern hemisphere, and Central Chile, Southwest Africa, and Southwest Australia in the southern, have "Mediterranean" climates. On the basis of climatic similarities, scholars have attempted to refine the Köppen system so that six major, and a total of sixteen, sub-types are now recognized globally. Being based to some extent on "native" vegetation, and not altogether on climate, critics consider the Köppen system to be a technical grouping rather than a true classification. Nevertheless, the Köppen system has proved to be a powerful teaching device that has not been superseded by other classifications. Although largely similar, each of the geographically separated Mediterranean areas have differences owing to local factors but, in comparison with other areas, they are more alike than different. This is also true of the other subtypes of the Köppen climatic classification. Critics assert that all places on Earth have some, if only minor, differences and thus cannot be classified.

The two examples of theoretical geography given above, with their origins in the past, have been fine-tuned and have become part of the curricula of geography departments, more than most other theories in a field that has been characterized as more empirical than theoretical. Since the mid-1970s, two developments have revolutionized geography—the computer and space exploration—as much as any previous advances.

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Science EncyclopediaScience & Philosophy: Gastrula to Glow dischargeGeography - The Nature Of Geography, Geographical Determinism, Military And Public Geography, Geographical Theories, The Limits In Geography