science that deals with the spatial distribution of all phenomena on the earth's surface. The word geography was adopted in the 3d century bc by the Greek scholar Eratosthenes and means “earth description.” Geographic study encompasses the environment of the surface of the earth and the relationship of humans to this environment, which includes both physical and cultural geographic features. Physical geographic features include the climate, land and water, and plant and animal life. Cultural geographic features include artificial entities, such as nations, settlements, lines of communication, transportation, buildings, and other modifications of the physical geographic environment. Geographers make use of the disciplines of economics, history, systematic botany, geology, and mathematics in their studies.

BRANCHES OF GEOGRAPHY

The science may be divided into two fundamental branches: systematic and regional geography. Systematic geography is concerned with individual physical and cultural phenomena. Regional geography is concerned with various areas of the surface of the earth for the purpose of determining the peculiar combinations of physical and cultural features that characterize each region and distinguish one region from another. Because the division is based only on a difference in approach to geographic studies, the two branches are interdependent and ordinarily are combined in practical applications. Each branch is further subdivided into several fields to permit specialization in particular aspects of the comprehensive study.

Systematic Geography.

This branch encompasses the major classifications of physical geography and cultural geography. Each classification comprises the specialized fields dealing with the spatial aspects of specific phenomena, rather than with the phenomena, per se, that constitute the focus of disciplines other than geography.

Physical geography.

Physical geography includes the following fields: geomorphology, allied to GEOLOGY (q.v.) and dealing with the form and structure of the surface of the earth; climatology, allied to METEOROLOGY, (q.v.) and concerned with climatic conditions; biogeography, allied to BIOLOGY, (q.v.) and dealing with plant and animal life; soils geography, allied to podology (see SOIL,; SOIL MANAGEMENT,) and concerned with the distribution of soil; hydrography, allied to hydrology and dealing with the distribution of seas, lakes, rivers, and streams in relation to the utilization of their waters; oceanography, which deals with the waves, tides, and currents of oceans and the ocean floor (see OCEAN AND OCEANOGRAPHY,); and cartography, allied to mathematics and geodesy and dealing with graphic representation and measurement of the surface of the earth.

Cultural geography.

This classification, sometimes called human geography, embraces virtually all phases of human social life in relation to the physical earth. Economic geography deals with the industrial use of the geographic environment. Natural resources, such as mineral and oil deposits, forests, grazing lands, and farmlands, are studied with reference to their situation, productivity, and potential. Manufacturing industries rely on geographic studies for information concerning raw materials, labor, supply, and ease of distribution. Marketing studies concerned with plant locations and sales potential are based on geographic considerations. The establishment of transportation facilities, trade routes, and resort areas frequently depends on the results of geographic studies.

Cultural geography also includes political geography, which is allied to POLITICAL SCIENCE, (q.v.). This field deals with human social activities that are related to the locations and boundaries of cities, nations, and groups of nations.

Military geography constitutes a continuing study for the purpose of providing military leaders with an intimate knowledge of all areas in which they may be required to operate. Among the many other fields of cultural geography are ethnography, allied to ETHNOLOGY, (q.v.), historical geography, urban geography, demography, and linguistic geography.

Regional Geography.

This branch of geography is concerned with the differences and similarities among the various regions of the earth. Regional geography seeks explanations for this variety among places by studying in each area the peculiar combination of spatially related features that distinguishes it from bordering areas.

Studies in regional geography may be restricted to the intensive development of a small area (the study of which is called microgeography) or may include large areas, such as Asia, Latin America, or the Mediterranean region. The broad areas, called macrodivisions, are based on the similarity of certain cultural criteria within each region.

In each of the large cultural regions, numerous smaller areas with further distinguishing characteristics may be identified. For example, a particular area may be differentiated from its surrounding areas by language, by the predominant type of agriculture, by the terrain, by the market orientation, or by the combination of two or more such characteristics.

TOOLS AND METHODS OF GEOGRAPHY

Before the 19th century geographic writing could be characterized as descriptive, that is, it was largely the simple recording of observations and data. As more accurate methods of obtaining and analyzing data were developed, geographic writings became more explanatory, and after the mid-20th century, more theoretical.

It remains the geographer's goal, however, to describe the human habitat on the surface of the earth. To do this it is necessary to record the results of both systematic and regional studies. Geographers have compiled many charts, graphs, and textbooks that record detailed observations of individual geographic features of the earth as a whole and of local regions. When used for comparative purposes, this type of material is easiest to understand if it is supported by graphic representations such as maps. See MAP,.

Data Collection.

Data may be collected in the field or from secondary sources, such as censuses, statistical surveys, maps, and photographs. Advances made since World War II in the design of aerial cameras and high-resolution lenses, in aerial photogrammetric techniques, including the use of special infrared and other films, and in techniques for obtaining three-dimensional views of the landscape from the air have made possible more detailed studies of the earth and its resources. Geographers have also made use of radar, artificial satellites, bathysphere descents, and deep drilling into the earth's crust to obtain information about the environmental features of the earth. With the great increase in available data produced by these advances, geographers have begun to use the computer both to list and to analyze data.

Mapping.

The map is the most important tool of geography and may be used to record either simple data or the results of a geographic study. In addition to providing a wealth of factual information, the map permits a visual comparison between areas because it may be designed to indicate, by means of symbols, not only the existence but also the form of all geographic features of a given area.

A standard pattern of cultural map symbols has been developed for identifying such cultural features as homes, factories, and churches; dams, bridges, and tunnels; railways, highways, and travel routes; and mines, farms, and grazing lands.

Quantitative Methods.

Techniques that employ mathematical or statistical processes to analyze data are known as quantitative methods. The use of quantitative methods enables geographers to treat a larger amount of data and a larger number of variables in a more objective manner. Frequently, geographers collect data and then advance a theoretical explanation for an observed phenomenon. They then test this theory using quantitative methods. Sometimes the theories are expressed as mathematical statements, called models. Nevertheless, in geography, where the human variable is almost always present, theories are not expected to be universally precise, but rather to explain an observed tendency.

HISTORY OF GEOGRAPHY

Hundreds of individuals have contributed to the development of geography, and the fruits of their work have accumulated for several thousand years. Numerous travelers, surveyors, explorers, and scientific observers have added to this growing store of information. Only during the last two centuries, however, has it been possible to collect and record really accurate geographic information. The major conceptual framework that guides present-day geographers is of even more recent derivation, having originated in the 19th century.

Early Geographers.

The earliest geographers were concerned with exploring unknown areas and with describing the observable features of individual places. In antiquity such ancient peoples as the Chinese, Egyptians, and Phoenicians made long journeys and recorded their observations of strange lands. One of the first known maps was made on a clay tablet in Babylonia as early as 2300 bc. By 1400 bc the shores of the Mediterranean Sea had been explored and charted, and during the next thousand years Britain was visited, and most of the African coastline was navigated.

The ancient Greeks, however, gave the Western world its first important knowledge relating to the form, size, and general nature of the earth.

Aristotle in the 4th century bc was the first to demonstrate that the earth was actually round. He based his hypothesis on the arguments that all matter tends to fall together toward a common center, that the earth throws a circular shadow on the moon during an eclipse, and that in traveling from north to south new constellations become visible and familiar ones disappear. The Greek geographer Eratosthenes calculated with amazing accuracy the circumference of the earth.

The Greeks' travels, conquests, and colonizing activities in the Mediterranean region resulted in the accumulation of considerable geographic information and stimulated geographic writing.

The early Roman geographers produced a number of massive works on geography, notably a 17-volume encyclopedia by the Greek geographer and historian Strabo that served as a valuable source of information for military commanders and public administrators of the Roman Empire.

In the 2d century ad the Alexandrian astronomer Ptolemy synthesized accumulated Greek and Roman geographic learning. In his famous Geographike syntaxis he divided the equatorial circle into 360 degrees and constructed an imaginary north-south, east-west network over the surface of the earth to serve as a reference grid for locating the relative positions of known landmasses, such as islands and continents. Although he elected to use less accurate measurements of the circumference of the earth than those of Eratosthenes, Ptolemy nevertheless contributed useful descriptions and maps of the known world. His maps clearly indicated his understanding of the problems involved in representing a spherical earth on a plane surface.

Medieval Geography.

During the Middle Ages little travel and exploration and practically no advancement in geography took place. Among Europeans only the Vikings were active in exploration. The Arabs, however, interpreted and tested the works of the earlier Greek and Roman geographers and explored southwestern Asia and Africa. As early as the 8th century Muslim scholars were translating the works of the Greek geographers into Arabic; only after these Arabic texts had been translated into Latin did Greek geographic learning become known in the Christian world. Among the major figures of Arab geography were al-Idrisi, who was known for his detailed maps, and Ibn Batuta and Ibn Khaldun, both of whom wrote about their extensive travels. The Mongols and Chinese also learned much about Asia, but their findings on the whole remained unknown to the Western world.

The trips of the Venetian Marco Polo in the 13th century, the Crusades of the 12th and 13th centuries, and the Portuguese and Spanish voyages of exploration of the 15th and 16th centuries opened up new horizons and stimulated geographic writings. Among the most notable of the accounts of voyages and discoveries that were published in the 16th century were those by the Venetian Giambattista Ramusio (1485– 1557), by Richard Hakluyt in England, and by Theodore de Bry (1528–98) in what is now Belgium. No longer could the concept of a spherical earth be considered heretical, as ecclesiastical authorities previously had contended, for exploration proved beyond a doubt the global nature of the earth.

Geography from the 17th to the 19th Century.

Important in the history of geographic method is Geographia generalis (1650) by the German geographer Bernhardus Varenius. Varenius suggested that geography be divided into three separate branches, the first dealing with the form and dimensions of the earth; the second with tides, climates, seasons, and other variables depending upon the relative position of the earth in the cosmos; and the third dealing with comparative studies of particular regions on the globe. His work remained a standard authority for more than a century.

The first comprehensive geographic work printed in English was published in 1625 by the English geographer Nathaniel Carpenter (1589–1628?), who emphasized the spatial interrelationships of the physical features on the earth's surface. His approach subsequently became an important geographic point of view.

Many other European contributors increased geographic knowledge during the following two centuries. In the 18th century the German philosopher Immanuel Kant played a decisive role in placing geography within the framework of science. Kant divided knowledge gained from observation into two categories. One category, comprising phenomena perceived in accordance with a logical system, resulted in such classifications as the orders, genera, and species of plants and animals, regardless of when or where they occur. The other category included phenomena perceived in terms of time and space, with classification and description according to time viewed as history, and classification and description according to space viewed as geography. Kant subdivided geography into six branches, one of which, physical geography, was considered basic to the five other branches. The other branches recognized by Kant were mathematical, moral, political, commercial, and theological geography.

Alexander von Humboldt and Carl Ritter, both of Germany, made major contributions to geographic theory in the early 19th century. An extensive traveler and a brilliant field observer, Humboldt applied his knowledge of physical processes to the systematic classification and comparative description of phenomena observed in the field and devised methods for measuring the phenomena he observed. Humboldt produced a number of superb geographic studies based on his travels in America. His work Kosmos (1844), which describes the physical geography of the earth, is considered one of the great geographic works of all time.

The views of Ritter differed in part from those of Humboldt. Whereas Humboldt utilized the systematic approach of treating physical features as separate phenomena, Ritter contributed greatly to the regional approach to geography. He laid stress on the comparative study of particular areas and on the associated features that characterized those areas. His 19-volume work Die Erdkunde im Verhaltnis zur Natur und Geschichte des Menschen (Geography and Its Relation to Nature and the History of Man, 1822–59) is a masterly treatment of Asia and parts of Africa. Ritter was a keen field observer, well trained in natural sciences and history. He called his work comparative geography, considering it analogous to comparative anatomy, and proceeded from observation to observation to arrive at laws and principles. Although his approach was largely regional rather than systematic, Ritter acknowledged that without systematic studies regional studies would be impossible.

Another German geographer, Friedrich Ratzel, also made significant contributions to geographic thinking. He is best known for his work Anthropogeographie (1882), which attempted to show that the distribution of people on the earth had been determined by natural forces. Describing geography as the science of distribution, he favored the study of restricted areas, which he claimed would provide the basis for generalizations about larger areas or about the world as a whole. The German geographers Ferdinand von Richthofen and Alfred Hettner (1859–1942) welded the ideas of Humboldt, Ritter, and Ratzel into a coherent system. Die Geographie: Ihre Geschichte, ihr Wesen, und ihre Methoden (Geography: Its History, Its Nature, and Its Methods, 1927), by Hettner, is a valuable work on the history of geographic methodology.

Outstanding among French geographers of the late 19th century was Paul Vidal de la Blache, who opposed the idea that the physical environment strictly determines human activities. He viewed human beings as determining agents operating in a physical environment, which could be molded to their needs in accordance with their development. He favored studies of small areas, stressing spatial differentiations as a result of both physical and cultural processes.

Greatly facilitating the emergence of geographic learning in the 19th century was the establishment of geographic societies, many of which sponsored geographic study and exploration and published periodicals devoted to geographic study. Among the earliest of these societies were those at Paris (1821), Berlin (1827), and London (Royal Geographical Society, 1830). Of particular significance to geography in the U.S. was the founding of the American Geographic Society in 1852 and the National Geographic Society in 1888. International geographic conferences were initiated in 1871 at Antwerp.

The 20th Century.

During the first half of the 20th century, numerous geographic writers—British, American, French, and German—continued to carry on the tradition of their German and French predecessors. Studies of small areas all over the world, based on field observations, extended the frontiers of geographic knowledge, but the traditions and methodology inherited from the late 19th century remained essentially unaltered. Beginning in the 1950s, however, geographers made increasing use of quantitative methods. The change in methodology in the 1950s and '60s was so rapid that it is sometimes called the quantitative revolution. The goals of the geographer have remained basically the same, although the tendency now is to find practical applications for geographic studies.

Location theory, which is concerned with the analysis of variables that influence the location of an entity (such as a town or a factory), has been in the vanguard in its use of quantitative methods. The seminal work of location theory, done by the German agriculturalist Johann Heinrich von Thünen (1783–1850), is strikingly modern in its methodology. Thünen devised a method of analysis to explain the relationship of several variables that influence the location of agricultural activities. He also constructed a model of this arrangement under ideal conditions. In the 1930s the German geographer Walter Christaller proposed a central place theory to explain the location of urban centers in quantitative terms. The value of the work of these men was not fully realized until the 1950s.

By the 1960s the unity of the discipline had given way to diversity, and a certain amount of friction developed between geographers who used the quantitative approach and those who used a more descriptive approach. In the 1970s the descriptive approach was used with new vigor, and proponents revived interest in the field when they turned to studies such as the human perception of geographic phenomena, regional studies, and medical geography. The quantitative and descriptive approaches have not only continued to coexist, but have been mutually influential. See also GEOPHYSICS,.        J.H.T., JOHN H. THOMPSON, M.A., Ph.D. & G.J.M., GEOFFREY J. MARTIN, Ph.D.

For additional information on individual geographers, see biographies of those whose names are not followed by dates.

For further information on this topic, see the Bibliography, sections 861. Geography–863. Travel guides, 866. Exploration, geographic.