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In modern mapping, a topographic map is a type of map characterized by large-scale detail and quantitative representation of relief, usually now using contour lines, but historically using a variety of methods. Traditional definitions require a topographic map to show both natural and man-made features. A topographic map is typically published as a map series, made up of two or more map sheets that combine to form the whole map. A contour line is a line connecting places of equal elevation. The Canadian Centre for Topographic Information provides this definition:〔Centre for Topographic Information, (Topo Maps: Frequently Asked Questions )〕 Other authors define topographic maps by contrasting them with another type of map; they are distinguished from smaller-scale "chorographic maps" that cover large regions,〔P. D. A. Harvey, ''The History of Topographical Maps: Symbols, Pictures and Surveys'', Thames and Hudson, 1980, ISBN 0-500-24105-8, p. 9. "By a topographical map, we mean a large-scale map, one that sets out to convey the shape and pattern of landscape, showing a tiny portion of the earth's surface as it lies within one's own direct experience, and quite distinct from the small-scale maps that show us the features of whole provinces, nations and continents."〕〔Art & Architecture Thesaurus entry for (topographic maps ).〕 "planimetric maps" that do not show elevations,〔Committee on Nomenclature of the American Society of Photogrammetry, "Definitions of terms used in photogrammetric surveying and mapping: preliminary report", ''Photogrammetric Engineering'', 8, 247-283, 1942. "Topographic Map. A map that presents the horizontal and vertical positions of the features represented; distinguished from a planimetric map by the addition of relief in measurable form." This definition is used in many glossaries of map terminology.〕 and "thematic maps" that focus on specific topics.〔M.-J. Kraak and F. Ormeling, ''Cartography: Visualization of Spatial Data'', Longman, 1996, ISBN 0-582-25953-3, p. 44. "Traditionally, the main division of maps is into topographic and thematic maps. Topographic maps supply a general image of the earth's surface: roads, rivers, buildings, often the nature of the vegetation, the relief and the names of the various mapped objects."〕 However, in the vernacular and day to day world, the representation of relief (contours) is popularly held to define the genre, such that even small-scale maps showing relief are commonly (and erroneously, in the technical sense) called "topographic".〔 The study or discipline of topography is a much broader field of study, which takes into account all natural and man-made features of terrain. ==History== Topographic maps are based on topographical surveys. Performed at large scales, these surveys are called topographical in the old sense of topography, showing a variety of elevations and landforms.〔The range of information is indicated by the title of a map produced in 1766: ''A Topographical Map of Hartfordshire from an Actual Survey in which is Express'd all the Roads, Lanes, Churches, Noblemen and Gentlemen's Seats, and every Thing remarkable in the County'', by Andrew Dury and John Andrews, reprinted by Hertfordshire Publications in 1980. This showed the relief by using hachures.〕 This is in contrast to older cadastral surveys, which primarily show property and governmental boundaries. The first multi-sheet topographic map series of an entire country, the ''Carte géométrique de la France'', was completed in 1789.〔Library of Congress, (Geography and Maps: General Collections )〕 The Great Trigonometric Survey of India, started by the East India Company in 1802, then taken over by the British Raj after 1857 was notable as a successful effort on a larger scale and for accurately determining heights of Himalayan peaks from viewpoints over one hundred miles distant.〔 〕 Topographic surveys were prepared by the military to assist in planning for battle and for defensive emplacements (thus the name and history of the United Kingdom's Ordnance Survey). As such, elevation information was of vital importance.〔Peter Barber, ''The Map Book'', Weidenfeld & Nicolson, 2005, ISBN 0-297-84372-9, pp. 232, 250.〕 As they evolved, topographic map series became a national resource in modern nations in planning infrastructure and resource exploitation. In the United States, the national map-making function which had been shared by both the Army Corps of Engineers and the Department of the Interior migrated to the newly created United States Geological Survey in 1879, where it has remained since.〔 〕〔 〕 1913 saw the beginning of the International Map of the World initiative, which set out to map all of Earth's significant land areas at a scale of 1:1 million, on about one thousand sheets, each covering four degrees latitude by six or more degrees longitude. Excluding borders, each sheet was 44 cm high and (depending on latitude) up to 66 cm wide. Although the project eventually foundered, it left an indexing system that remains in use. By the 1980s, centralized printing of standardized topographic maps began to be superseded by databases of coordinates that could be used on computers by moderately skilled end users to view or print maps with arbitrary contents, coverage and scale. For example, the Federal government of the United States' ''TIGER'' initiative compiled interlinked databases of federal, state and local political borders and census enumeration areas, and of roadways, railroads, and water features with support for locating street addresses within street segments. TIGER was developed in the 1980s and used in the 1990 and subsequent decennial censuses. Digital elevation models (''DEM'') were also compiled, initially from topographic maps and stereographic interpretation of aerial photographs and then from satellite photography and radar data. Since all these were government projects funded with taxes and not classified for national security reasons, the datasets were in the public domain and freely usable without fees or licensing. TIGER and DEM datasets greatly facilitated Geographic information systems and made the Global Positioning System much more useful by providing context around locations given by the technology as coordinates. Initial applications were mostly professionalized forms such as innovative surveying instruments and agency-level GIS systems tended by experts. By the mid-1990s, increasingly user-friendly resources such as online mapping in two and three dimensions, integration of GPS with mobile phones and automotive navigation systems appeared. As of 2011, the future of standardized, centrally printed topographical maps is left somewhat in doubt.〔 〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Topographic map」の詳細全文を読む スポンサード リンク
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