topographic mapping
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In modern mapping, a topographic map or topographic sheet is a type of
map A map is a symbolic depiction of interrelationships, commonly spatial, between things within a space. A map may be annotated with text and graphics. Like any graphic, a map may be fixed to paper or other durable media, or may be displayed on ...
characterized by large- scale detail and quantitative representation of relief features, usually using
contour line A contour line (also isoline, isopleth, isoquant or isarithm) of a Function of several real variables, function of two variables is a curve along which the function has a constant value, so that the curve joins points of equal value. It is a ...
s (connecting points of equal elevation), but historically using a variety of methods. Traditional definitions require a topographic map to show both natural and artificial features. A topographic survey is typically based upon a systematic observation and published as a
map series A map series is a group of topographic map, topographic or thematic map, thematic charts or maps usually having the same scale and cartographic specifications, and with each sheet appropriately identified by its publisher as belonging to the same ...
, made up of two or more map sheets that combine to form the whole map. A topographic map series uses a common specification that includes the range of cartographic symbols employed, as well as a standard geodetic framework that defines the
map projection In cartography, a map projection is any of a broad set of Transformation (function) , transformations employed to represent the curved two-dimensional Surface (mathematics), surface of a globe on a Plane (mathematics), plane. In a map projection, ...
,
coordinate system In geometry, a coordinate system is a system that uses one or more numbers, or coordinates, to uniquely determine and standardize the position of the points or other geometric elements on a manifold such as Euclidean space. The coordinates are ...
,
ellipsoid An ellipsoid is a surface that can be obtained from a sphere by deforming it by means of directional Scaling (geometry), scalings, or more generally, of an affine transformation. An ellipsoid is a quadric surface;  that is, a Surface (mathemat ...
and
geodetic datum A geodetic datum or geodetic system (also: geodetic reference datum, geodetic reference system, or geodetic reference frame, or terrestrial reference frame) is a global datum reference or reference frame for unambiguously representing the positi ...
. Official topographic maps also adopt a national grid referencing system.
Natural Resources Canada Natural Resources Canada (NRCan; ; )Natural Resources Canada is the applied title under the Federal Identity Program; the legal title is Department of Natural Resources (). is the department of the Government of Canada responsible for natural r ...
provides this description of topographic maps: 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,
Art & Architecture Thesaurus The Art & Architecture Thesaurus (AAT) is a controlled vocabulary used for describing items of art, architecture, and material culture. The AAT contains generic terms, such as "cathedral", but no proper names, such as "Cathedral of Notre Dame." Th ...
entry fo
topographic maps
.
" planimetric maps" that do not show elevations, and "
thematic map A thematic map is a type of map that portrays the geographic pattern of a particular subject matter (theme) in a geographic area. This usually involves the use of map symbols to Geovisualization, visualize selected properties of geographic fe ...
s" that focus on specific topics. 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 Topography is the study of the forms and features of land surfaces. The topography of an area may refer to the landforms and features themselves, or a description or depiction in maps. Topography is a field of geoscience and planetary sci ...
is a much broader field of study, which takes into account all
natural Nature is an inherent character or constitution, particularly of the ecosphere or the universe as a whole. In this general sense nature refers to the laws, elements and phenomena of the physical world, including life. Although humans are part ...
and human-made features of terrain. Maps were among the first artifacts to record observations about topography.


History

Topographic maps are based on topographical surveys. Performed at large scales, these surveys are called topographical in the old sense of
topography Topography is the study of the forms and features of land surfaces. The topography of an area may refer to the landforms and features themselves, or a description or depiction in maps. Topography is a field of geoscience and planetary sci ...
, showing a variety of elevations and landforms. This is in contrast to older
cadastral survey Cadastral surveying is the sub-field of cadastre and surveying that specialises in the establishment and re-establishment of Real estate, real property boundaries. It involves the physical delineation of property boundaries and determination of dim ...
s, 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. The
Great Trigonometric Survey The Great Trigonometrical Survey of India was a project that aimed to carry out a wikt:Special:Search/survey, survey across the Indian subcontinent with scientific precision. It was begun in 1802 by the British infantry officer William Lambton ...
of India, started by the
East India Company The East India Company (EIC) was an English, and later British, joint-stock company that was founded in 1600 and dissolved in 1874. It was formed to Indian Ocean trade, trade in the Indian Ocean region, initially with the East Indies (South A ...
in 1802, then taken over by the
British Raj The British Raj ( ; from Hindustani language, Hindustani , 'reign', 'rule' or 'government') was the colonial rule of the British The Crown, Crown on the Indian subcontinent, * * lasting from 1858 to 1947. * * It is also called Crown rule ...
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 The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Northwestern Europe, off the coast of European mainland, the continental mainland. It comprises England, Scotlan ...
's
Ordnance Survey The Ordnance Survey (OS) is the national mapping agency for Great Britain. The agency's name indicates its original military purpose (see Artillery, ordnance and surveying), which was to map Scotland in the wake of the Jacobite rising of ...
). As such, elevation information was of vital importance. 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 The United States Department of the Interior (DOI) is an executive department of the U.S. federal government responsible for the management and conservation of most federal lands and natural resources. It also administers programs relatin ...
migrated to the newly created
United States Geological Survey The United States Geological Survey (USGS), founded as the Geological Survey, is an agency of the U.S. Department of the Interior whose work spans the disciplines of biology, geography, geology, and hydrology. The agency was founded on Mar ...
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 The Federal Government of the United States of America (U.S. federal government or U.S. government) is the Federation#Federal governments, national government of the United States. The U.S. federal government is composed of three distinct ...
' ''
TIGER The tiger (''Panthera tigris'') is a large Felidae, cat and a member of the genus ''Panthera'' native to Asia. It has a powerful, muscular body with a large head and paws, a long tail and orange fur with black, mostly vertical stripes. It is ...
'' initiative compiled interlinked databases of federal, state and local political
border Borders are generally defined as geography, geographical boundaries, imposed either by features such as oceans and terrain, or by polity, political entities such as governments, sovereign states, federated states, and other administrative divisio ...
s 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 model A digital elevation model (DEM) or digital surface model (DSM) is a 3D computer graphics representation of elevation data to represent terrain or overlaying objects, commonly of a planet, Natural satellite, moon, or asteroid. A "global DEM" refer ...
s (''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 The public domain (PD) consists of all the creative work to which no Exclusive exclusive intellectual property rights apply. Those rights may have expired, been forfeited, expressly Waiver, waived, or may be inapplicable. Because no one holds ...
and freely usable without fees or licensing. TIGER and DEM datasets greatly facilitated
geographic information system A geographic information system (GIS) consists of integrated computer hardware and Geographic information system software, software that store, manage, Spatial analysis, analyze, edit, output, and Cartographic design, visualize Geographic data ...
s and made the
Global Positioning System The Global Positioning System (GPS) is a satellite-based hyperbolic navigation system owned by the United States Space Force and operated by Mission Delta 31. It is one of the global navigation satellite systems (GNSS) that provide ge ...
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 Instruments used in surveying include: * Alidade * Alidade table * Cosmolabe * Dioptra * Dumpy level * Engineer's chain * Geodimeter * Graphometer * Groma (surveying) * Laser scanning * Level * Level staff * Measuring tape * Plane table * ...
and agency-level GIS systems tended by experts. By the mid-1990s, increasingly
user-friendly Usability can be described as the capacity of a system to provide a condition for its users to perform the tasks safely, effectively, and efficiently while enjoying the experience. In software engineering, usability is the degree to which a softw ...
resources such as online mapping in two and three dimensions, integration of GPS with
mobile phone A mobile phone or cell phone is a portable telephone that allows users to make and receive calls over a radio frequency link while moving within a designated telephone service area, unlike fixed-location phones ( landline phones). This rad ...
s and
automotive navigation system An automotive navigation system is part of the automobile controls or a third party add-on used to find direction in an automobile. It typically uses a satellite navigation device to get its position data which is then correlated to a position on ...
s appeared. As of 2011, the future of standardized, centrally printed topographical maps is left somewhat in doubt.


Uses

Topographic maps have many multiple uses in the present day: any type of geographic
planning Planning is the process of thinking regarding the activities required to achieve a desired goal. Planning is based on foresight, the fundamental capacity for mental time travel. Some researchers regard the evolution of forethought - the cap ...
or large-scale
architecture Architecture is the art and technique of designing and building, as distinguished from the skills associated with construction. It is both the process and the product of sketching, conceiving, planning, designing, and construction, constructi ...
;
Earth sciences Earth science or geoscience includes all fields of natural science related to the planet Earth. This is a branch of science dealing with the physical, chemical, and biological complex constitutions and synergistic linkages of Earth's four spheres ...
and many other
geographic Geography (from Ancient Greek ; combining 'Earth' and 'write', literally 'Earth writing') is the study of the lands, features, inhabitants, and phenomena of Earth. Geography is an all-encompassing discipline that seeks an understanding o ...
disciplines;
mining Mining is the Resource extraction, extraction of valuable geological materials and minerals from the surface of the Earth. Mining is required to obtain most materials that cannot be grown through agriculture, agricultural processes, or feasib ...
and other Earth-based endeavours;
civil engineering Civil engineering is a regulation and licensure in engineering, professional engineering discipline that deals with the design, construction, and maintenance of the physical and naturally built environment, including public works such as roads ...
and recreational uses such as
hiking A hike is a long, vigorous walk, usually on trails or footpaths in the countryside. Walking for pleasure developed in Europe during the eighteenth century. Long hikes as part of a religious pilgrimage have existed for a much longer time. "Hi ...
and
orienteering Orienteering is a group of sports that involve using a map and compass to navigation, navigate from point to point in diverse and usually unfamiliar terrain whilst moving at speed. Participants are given a topographical map, usually a specia ...
. It takes practice and skill to read and interpret a topographic map. This includes not only how to identify map features, but also how to interpret contour lines to infer landforms like cliffs, ridges, draws, etc. Training in map reading is often given in orienteering, scouting, and the military.


Conventions

The various features shown on the map are represented by conventional signs or symbols. For example, colors can be used to indicate a classification of roads. These signs are usually explained in the margin of the map, or on a separately published characteristic sheet. Topographic maps are also commonly called ''contour maps'' or ''topo maps''. In the United States, where the primary national series is organized by a strict 7.5-minute grid, they are often called or ''
quads The quadriceps femoris muscle (, also called the quadriceps extensor, quadriceps or quads) is a large muscle group that includes the four prevailing muscles on the front of the thigh. It is the sole extensor muscle of the knee, forming a large ...
'' or quadrangles. Topographic maps conventionally show
topography Topography is the study of the forms and features of land surfaces. The topography of an area may refer to the landforms and features themselves, or a description or depiction in maps. Topography is a field of geoscience and planetary sci ...
, or land contours, by means of
contour line A contour line (also isoline, isopleth, isoquant or isarithm) of a Function of several real variables, function of two variables is a curve along which the function has a constant value, so that the curve joins points of equal value. It is a ...
s. Contour lines are
curve In mathematics, a curve (also called a curved line in older texts) is an object similar to a line, but that does not have to be straight. Intuitively, a curve may be thought of as the trace left by a moving point. This is the definition that ...
s that connect contiguous points of the same
altitude Altitude is a distance measurement, usually in the vertical or "up" direction, between a reference datum (geodesy), datum and a point or object. The exact definition and reference datum varies according to the context (e.g., aviation, geometr ...
( isohypse). In other words, every point on the marked line of 100 m
elevation The elevation of a geographic location (geography), ''location'' is its height above or below a fixed reference point, most commonly a reference geoid, a mathematical model of the Earth's sea level as an equipotential gravitational equipotenti ...
is 100 m above mean sea level. These maps usually show not only the contours, but also any significant
stream A stream is a continuous body of water, body of surface water Current (stream), flowing within the stream bed, bed and bank (geography), banks of a channel (geography), channel. Depending on its location or certain characteristics, a strea ...
s or other bodies of
water Water is an inorganic compound with the chemical formula . It is a transparent, tasteless, odorless, and Color of water, nearly colorless chemical substance. It is the main constituent of Earth's hydrosphere and the fluids of all known liv ...
,
forest A forest is an ecosystem characterized by a dense ecological community, community of trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, ...
cover, built-up areas or individual buildings (depending on scale), and other features and points of interest such as what direction those streams are flowing. Most topographic maps were prepared using photogrammetric interpretation of
aerial photography Aerial photography (or airborne imagery) is the taking of photographs from an aircraft or other flight, airborne platforms. When taking motion pictures, it is also known as aerial videography. Platforms for aerial photography include fixed-wi ...
using a
stereoplotter A stereoplotter uses stereo photographs to determine elevations. It has been the primary method to plot contour lines on topographic maps since the 1930s. Although the specific devices have advanced technologically, they are all based on the app ...
. Modern mapping also employs
lidar Lidar (, also LIDAR, an acronym of "light detection and ranging" or "laser imaging, detection, and ranging") is a method for determining ranging, ranges by targeting an object or a surface with a laser and measuring the time for the reflected li ...
and other
Remote sensing Remote sensing is the acquisition of information about an physical object, object or phenomenon without making physical contact with the object, in contrast to in situ or on-site observation. The term is applied especially to acquiring inform ...
techniques. Older topographic maps were prepared using traditional
surveying Surveying or land surveying is the technique, profession, art, and science of determining the land, terrestrial Plane (mathematics), two-dimensional or Three-dimensional space#In Euclidean geometry, three-dimensional positions of Point (geom ...
instruments. The cartographic style (content and appearance) of topographic maps is highly variable between national mapping organizations. Aesthetic traditions and conventions persist in topographic map symbology, particularly amongst European countries at medium map scales.


Publishers of national topographic map series

Although virtually the entire terrestrial surface of Earth has been mapped at scale 1:1,000,000, medium and large-scale mapping has been accomplished intensively in some countries and much less in others. Several commercial vendors supply international topographic map series. According to 2007/2/EC
European directive A directive is a legal act of the European Union that requires member states to achieve particular goals without dictating how the member states achieve those goals. A directive's goals have to be made the goals of one or more new or changed na ...
, national mapping agencies of
European Union The European Union (EU) is a supranational union, supranational political union, political and economic union of Member state of the European Union, member states that are Geography of the European Union, located primarily in Europe. The u ...
countries must have publicly available services for searching, viewing and downloading their official map series. Topographic maps produced by some of them are available under a
free license A free license or open license is a license that allows copyrighted work to be reused, modified, and redistributed. These uses are normally prohibited by copyright, patent or other Intellectual property (IP) laws. The term broadly covers '' fr ...
that allows re-use, such as a
Creative Commons Creative Commons (CC) is an American non-profit organization and international network devoted to educational access and expanding the range of creative works available for others to build upon legally and to share. The organization has release ...
license.


See also

*
Aeronautical chart An aeronautical chart is a map designed to assist in the navigation of aircraft, much as nautical charts do for watercraft, or a roadmap does for drivers. Using these charts and other tools, pilots are able to determine their position, safe alt ...
*
Bathymetric chart A bathymetric chart is a type of isarithmic map that depicts the submerged bathymetry and physiographic features of ocean and sea bottoms. Their primary purpose is to provide detailed depth contours of ocean topography as well as provide the si ...
*
Cadastral map A cadastre or cadaster ( ) is a comprehensive recording of the real estate or real property's metes and bounds, metes-and-bounds of a country.Jo Henssen, ''Basic Principles of the Main Cadastral Systems in the World,'/ref> Often it is represente ...
*
Thematic map A thematic map is a type of map that portrays the geographic pattern of a particular subject matter (theme) in a geographic area. This usually involves the use of map symbols to Geovisualization, visualize selected properties of geographic fe ...
*
Hypsometric tints Hypsometric tints (also called layer tinting, elevation tinting, elevation coloring, or hysometric coloring) are colors placed between contour lines to indicate elevation. These tints are shown as bands of color in a graduated scheme or as a col ...
* International Map of the World * (List of) national mapping agencies *
Nautical chart A nautical chart or hydrographic chart is a graphic representation of a sea region or water body and adjacent coasts or river bank, banks. Depending on the scale (map), scale of the chart, it may show depths of water (bathymetry) and heights of ...
* Raised-relief map *
Stereoplotter A stereoplotter uses stereo photographs to determine elevations. It has been the primary method to plot contour lines on topographic maps since the 1930s. Although the specific devices have advanced technologically, they are all based on the app ...
*
Topo (climbing) In climbing, a topo (short for topology) is a graphical representation of a climbing route. Topos range from a photograph of the climb on which the line of the route is overlaid, to a detailed diagram of the key features and challenges of the cl ...
* TopoFusion *
Topographic profile A topographic profile or topographic cut or elevation profile is a representation of the relief of the terrain that is obtained by cutting transversely the lines of a topographic map. Each contour line can be defined as a closed line joining relie ...


References


External links

* USGS Topographic maps are downloadable as pdf file
from a searchable map
o
by a search if the map name is known


* ttps://topo.icaci.org The International Cartographic Association (ICA) Commission on Topographic Mapping {{Authority control Relief maps
Map A map is a symbolic depiction of interrelationships, commonly spatial, between things within a space. A map may be annotated with text and graphics. Like any graphic, a map may be fixed to paper or other durable media, or may be displayed on ...