Map

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World map by Gerard van Schagen, Amsterdam, 1689 World Map 1689.JPG
World map by Gerard van Schagen, Amsterdam, 1689
World map from CIA World Factbook, 2016 Map of the world by the US Gov as of 2016.svg
World map from CIA World Factbook , 2016

A map is a symbolic depiction emphasizing relationships between elements of some space, such as objects, regions, or themes.

Contents

Many maps are static, fixed to paper or some other durable medium, while others are dynamic or interactive. Although most commonly used to depict geography, maps may represent any space, real or fictional, without regard to context or scale, such as in brain mapping, DNA mapping, or computer network topology mapping. The space being mapped may be two dimensional, such as the surface of the earth, three dimensional, such as the interior of the earth, or even more abstract spaces of any dimension, such as arise in modeling phenomena having many independent variables.

Although the earliest maps known are of the heavens, geographic maps of territory have a very long tradition and exist from ancient times. The word "map" comes from the medieval Latin : Mappa mundi, wherein mappa meant 'napkin' or 'cloth' and mundi 'the world'. Thus, "map" became a shortened term referring to a two-dimensional representation of the surface of the world.

History

Tabula Rogeriana, one of the most advanced early world maps, by Muhammad al-Idrisi's, 1154 TabulaRogeriana upside-down.jpg
Tabula Rogeriana , one of the most advanced early world maps, by Muhammad al-Idrisi's, 1154

The history of cartography traces the development of cartography, or mapmaking technology, in human history. Maps have been one of the most important human inventions for millennia, allowing humans to explain and navigate their way through the world. The earliest surviving maps include cave paintings and etchings on tusk and stone, followed by extensive maps produced by ancient Babylon, Greece and Rome, China, and India. In their most simple form maps are two dimensional constructs, however since the age of Classical Greece maps have also been projected onto a three-dimensional sphere known as a globe. The Mercator Projection, developed by Flemish geographer Gerardus Mercator, was widely used as the standard two-dimensional projection of the earth for world maps until the late 20th century, when more accurate projections were formulated. Mercator was also the first to use and popularise the concept of the atlas as a collection of maps.

Geography

Celestial map by the cartographer Frederik de Wit, 17th century Planisphaeri coeleste.jpg
Celestial map by the cartographer Frederik de Wit, 17th century

Cartography or map-making is the study and practice of crafting representations of the Earth upon a flat surface (see History of cartography), and one who makes maps is called a cartographer.

Road maps are perhaps the most widely used maps today, and form a subset of navigational maps, which also include aeronautical and nautical charts, railroad network maps, and hiking and bicycling maps. In terms of quantity, the largest number of drawn map sheets is probably made up by local surveys, carried out by municipalities, utilities, tax assessors, emergency services providers, and other local agencies. Many national surveying projects have been carried out by the military, such as the British Ordnance Survey: a civilian government agency, internationally renowned for its comprehensively detailed work.

In addition to location information, maps may also be used to portray contour lines indicating constant values of elevation, temperature, rainfall, etc.

Orientation

The Hereford Mappa Mundi, Hereford Cathedral, England, circa 1300, a classic "T-O" map with Jerusalem at the center, east toward the top, Europe the bottom left and Africa on the right Hereford-Karte.jpg
The Hereford Mappa Mundi , Hereford Cathedral, England, circa 1300, a classic "T-O" map with Jerusalem at the center, east toward the top, Europe the bottom left and Africa on the right

The orientation of a map is the relationship between the directions on the map and the corresponding compass directions in reality. The word "orient" is derived from Latin oriens, meaning east. In the Middle Ages many maps, including the T and O maps, were drawn with east at the top (meaning that the direction "up" on the map corresponds to East on the compass). The most common cartographic convention is that north is at the top of a map.

Map of Utrecht, Netherlands (1695). Atlas de Wit 1698-pl044-Utrecht-KB PPN 145205088.jpg
Map of Utrecht, Netherlands (1695).

Maps not oriented with north at the top:

Scale and accuracy

Many maps are drawn to a scale expressed as a ratio, such as 1:10,000, which means that 1 unit of measurement on the map corresponds to 10,000 of that same unit on the ground. The scale statement can be accurate when the region mapped is small enough for the curvature of the Earth to be neglected, such as a city map. Mapping larger regions, where the curvature cannot be ignored, requires projections to map from the curved surface of the Earth to the plane. The impossibility of flattening the sphere to the plane without distortion means that the map cannot have a constant scale. Rather, on most projections, the best that can be attained is an accurate scale along one or two paths on the projection. Because scale differs everywhere, it can only be measured meaningfully as point scale per location. Most maps strive to keep point scale variation within narrow bounds. Although the scale statement is nominal it is usually accurate enough for most purposes unless the map covers a large fraction of the earth. At the scope of a world map, scale as a single number is practically meaningless throughout most of the map. Instead, it usually refers to the scale along the equator.

Cartogram of the EU - distorted to show population distributions as of 2008 EU Pop2008 1024.PNG
Cartogram of the EU – distorted to show population distributions as of 2008

Some maps, called cartograms, have the scale deliberately distorted to reflect information other than land area or distance. For example, this map (at the right) of Europe has been distorted to show population distribution, while the rough shape of the continent is still discernible.

Another example of distorted scale is the famous London Underground map. The basic geographical structure is respected but the tube lines (and the River Thames) are smoothed to clarify the relationships between stations. Near the center of the map, stations are spaced out more than near the edges of the map.

Further inaccuracies may be deliberate. For example, cartographers may simply omit military installations or remove features solely to enhance the clarity of the map. For example, a road map may not show railroads, smaller waterways, or other prominent non-road objects, and even if it does, it may show them less clearly (e.g. dashed or dotted lines/outlines) than the main roads. Known as decluttering, the practice makes the subject matter that the user is interested in easier to read, usually without sacrificing overall accuracy. Software-based maps often allow the user to toggle decluttering between ON, OFF, and AUTO as needed. In AUTO the degree of decluttering is adjusted as the user changes the scale being displayed.

Projection

Geographic maps use a projection to translate the three-dimensional real surface of the geoid to a two-dimensional picture. Projection always distorts the surface. There are many ways to apportion the distortion, and so there are many map projections. Which projection to use depends on the purpose of the map. [4]

Symbology

The various features shown on a map are represented by conventional signs or symbols. For example, colors can be used to indicate a classification of roads. Those signs are usually explained in the margin of the map, or on a separately published characteristic sheet. [5]

Some cartographers prefer to make the map cover practically the entire screen or sheet of paper, leaving no room "outside" the map for information about the map as a whole. These cartographers typically place such information in an otherwise "blank" region "inside" the map cartouche, map legend, title, compass rose, bar scale, etc. In particular, some maps contain smaller "sub-maps" in otherwise blank regions—often one at a much smaller scale showing the whole globe and where the whole map fits on that globe, and a few showing "regions of interest" at a larger scale to show details that wouldn't otherwise fit. Occasionally sub-maps use the same scale as the large map—a few maps of the contiguous United States include a sub-map to the same scale for each of the two non-contiguous states.

Design

The design and production of maps is a craft that has developed over thousands of years, from clay tablets to Geographic information systems. As a form of Design, particularly closely related to Graphic design, map making incorporates scientific knowledge about how maps are used, integrated with principles of artistic expression, to create an aesthetically attractive product, carries an aura of authority, and functionally serves a particular purpose for an intended audience.

Designing a map involves bringing together a number of elements and making a large number of decisions. The elements of design fall into several broad topics, each of which has its own theory, its own research agenda, and its own best practices. That said, there are synergistic effects between these elements, meaning that the overall design process is not just working on each element one at a time, but an iterative feedback process of adjusting each to achieve the desired gestalt.

Types

Map of large underwater features. (1995, NOAA) Ocean gravity map.gif
Map of large underwater features. (1995, NOAA)
Geological map of the Moon The geologic map of the Moon at 1-2.5M scale.png
Geological map of the Moon

Maps of the world or large areas are often either 'political' or 'physical'. The most important purpose of the political map is to show territorial borders; the purpose of the physical is to show features of geography such as mountains, soil type, or land use including infrastructures such as roads, railroads, and buildings. Topographic maps show elevations and relief with contour lines or shading. Geological maps show not only the physical surface, but characteristics of the underlying rock, fault lines, and subsurface structures.

Electronic

A USGS digital raster graphic. Topographic map example.png
A USGS digital raster graphic.

From the last quarter of the 20th century, the indispensable tool of the cartographer has been the computer. Much of cartography, especially at the data-gathering survey level, has been subsumed by Geographic Information Systems (GIS). The functionality of maps has been greatly advanced by technology simplifying the superimposition of spatially located variables onto existing geographical maps. Having local information such as rainfall level, distribution of wildlife, or demographic data integrated within the map allows more efficient analysis and better decision making. In the pre-electronic age such superimposition of data led Dr. John Snow to identify the location of an outbreak of cholera. Today, it is used by agencies of humankind, as diverse as wildlife conservationists and militaries around the world.

Relief map of the Sierra Nevada Maps-for-free Sierra Nevada.png
Relief map of the Sierra Nevada

Even when GIS is not involved, most cartographers now use a variety of computer graphics programs to generate new maps.

Interactive, computerized maps are commercially available, allowing users to zoom in or zoom out (respectively meaning to increase or decrease the scale), sometimes by replacing one map with another of different scale, centered where possible on the same point. In-car global navigation satellite systems are computerized maps with route planning and advice facilities that monitor the user's position with the help of satellites. From the computer scientist's point of view, zooming in entails one or a combination of:

  1. replacing the map by a more detailed one
  2. enlarging the same map without enlarging the pixels, hence showing more detail by removing less information compared to the less detailed version
  3. enlarging the same map with the pixels enlarged (replaced by rectangles of pixels); no additional detail is shown, but, depending on the quality of one's vision, possibly more detail can be seen; if a computer display does not show adjacent pixels really separate, but overlapping instead (this does not apply for an LCD, but may apply for a cathode ray tube), then replacing a pixel by a rectangle of pixels does show more detail. A variation of this method is interpolation.
A world map in PDF format. World.pdf
A world map in PDF format.

For example:

Climatic

Mean Annual Temperature map of Ohio from "Geography of Ohio" 1923 Geography of Ohio - DPLA - aaba7b3295ff6973b6fd1e23e33cde14 (page 27) (cropped).jpg
Mean Annual Temperature map of Ohio from "Geography of Ohio" 1923

The maps that reflect the territorial distribution of climatic conditions based on the results of long-term observations are called climatic maps. These maps can be compiled both for individual climatic features (temperature, precipitation, humidity) and for combinations of them at the earth's surface and in the upper layers of the atmosphere. Climatic maps show climatic features across a large region and permit values of climatic features to be compared in different parts of the region. When generating the map, spatial interpolation can be used to synthesize values where there are no measurements, under the assumption that conditions change smoothly.

Climatic maps generally apply to individual months and the year as a whole, sometimes to the four seasons, to the growing period, and so forth. On maps compiled from the observations of ground meteorological stations, atmospheric pressure is converted to sea level. Air temperature maps are compiled both from the actual values observed on the surface of the earth and from values converted to sea level. The pressure field in the free atmosphere is represented either by maps of the distribution of pressure at different standard altitudes—for example, at every kilometer above sea level—or by maps of baric topography on which altitudes (more precisely geopotentials) of the main isobaric surfaces (for example, 900, 800, and 700 millibars) counted off from sea level are plotted. The temperature, humidity, and wind on aero climatic maps may apply either to standard altitudes or to the main isobaric surfaces.

Isolines are drawn on maps of such climatic features as the long-term mean values (of atmospheric pressure, temperature, humidity, total precipitation, and so forth) to connect points with equal values of the feature in question—for example, isobars for pressure, isotherms for temperature, and isohyets for precipitation. Isoamplitudes are drawn on maps of amplitudes (for example, annual amplitudes of air temperature—that is, the differences between the mean temperatures of the warmest and coldest month). Isanomals are drawn on maps of anomalies (for example, deviations of the mean temperature of each place from the mean temperature of the entire latitudinal zone). Isolines of frequency are drawn on maps showing the frequency of a particular phenomenon (for example, the annual number of days with a thunderstorm or snow cover). Isochrones are drawn on maps showing the dates of onset of a given phenomenon (for example, the first frost and appearance or disappearance of the snow cover) or the date of a particular value of a meteorological element in the course of a year (for example, passing of the mean daily air temperature through zero). Isolines of the mean numerical value of wind velocity or isotachs are drawn on wind maps (charts); the wind resultants and directions of prevailing winds are indicated by arrows of different lengths or arrows with different plumes; lines of flow are often drawn. Maps of the zonal and meridional components of wind are frequently compiled for the free atmosphere. Atmospheric pressure and wind are usually combined on climatic maps. Wind roses, curves showing the distribution of other meteorological elements, diagrams of the annual course of elements at individual stations, and the like are also plotted on climatic maps.

Maps of climatic regionalization, that is, division of the earth's surface into climatic zones and regions according to some classification of climates, are a special kind of climatic map.

Climatic maps are often incorporated into climatic atlases of varying geographic ranges (globe, hemispheres, continents, countries, oceans) or included in comprehensive atlases. Besides general climatic maps, applied climatic maps and atlases have great practical value. Aero climatic maps, aero climatic atlases, and agro climatic maps are the most numerous.

Extraterrestrial

Maps exist of the Solar System, and other cosmological features such as star maps. In addition maps of other bodies such as the Moon and other planets are technically not geo graphical maps. Floor maps are also spatial but not necessarily geospatial.

Topological

In a topological map, like this one showing inventory locations, the distances between locations are not important. Only the layout and connectivity between them matters. Inventory Locations Represented as a Map.png
In a topological map, like this one showing inventory locations, the distances between locations are not important. Only the layout and connectivity between them matters.

Diagrams such as schematic diagrams and Gantt charts and tree maps display logical relationships between items, rather than geographical relationships. Topological in nature, only the connectivity is significant. The London Underground map and similar subway maps around the world are a common example of these maps.

General

General-purpose maps provide many types of information on one map. Most atlas maps, wall maps, and road maps fall into this category. The following are some features that might be shown on general-purpose maps: bodies of water, roads, railway lines, parks, elevations, towns and cities, political boundaries, latitude and longitude, national and provincial parks. These maps give a broad understanding of the location and features of an area. The reader may gain an understanding of the type of landscape, the location of urban places, and the location of major transportation routes all at once.

List

Some countries required that all published maps represent their national claims regarding border disputes. For example:

In 2010, the People's Republic of China began requiring that all online maps served from within China be hosted there, making them subject to Chinese laws. [10]

See also

General
Map designing and types
Map history
Related topics

Related Research Articles

<span class="mw-page-title-main">Cartography</span> Study and practice of making maps

Cartography is the study and practice of making and using maps. Combining science, aesthetics and technique, cartography builds on the premise that reality can be modeled in ways that communicate spatial information effectively.

<span class="mw-page-title-main">Geographic information system</span> System to capture, manage and present geographic data

A geographic information system (GIS) is a type of database containing geographic data, combined with software tools for managing, analyzing, and visualizing those data. In a broader sense, one may consider such a system to also include human users and support staff, procedures and workflows, body of knowledge of relevant concepts and methods, and institutional organizations.

<span class="mw-page-title-main">Map projection</span> Systematic representation of the surface of a sphere or ellipsoid onto a plane

In cartography, map projection is the term used to describe a broad set of transformations employed to represent the two-dimensional curved surface of a globe on a plane. In a map projection, coordinates, often expressed as latitude and longitude, of locations from the surface of the globe are transformed to coordinates on a plane. Projection is a necessary step in creating a two-dimensional map and is one of the essential elements of cartography.

<span class="mw-page-title-main">Topography</span> Study of the forms of land surfaces

Topography is the study of the forms and features of land surfaces. The topography of an area may refer to the land forms and features themselves, or a description or depiction in maps.

2.5D perspective refers to one of two things:

<span class="mw-page-title-main">Contour line</span> Curve along which a 3-D surface is at equal elevation

A contour line of a 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 plane section of the three-dimensional graph of the function parallel to the -plane. More generally, a contour line for a function of two variables is a curve connecting points where the function has the same particular value.

<span class="mw-page-title-main">World map</span> Map of most or all of the surface of the Earth

A world map is a map of most or all of the surface of Earth. World maps, because of their scale, must deal with the problem of projection. Maps rendered in two dimensions by necessity distort the display of the three-dimensional surface of the earth. While this is true of any map, these distortions reach extremes in a world map. Many techniques have been developed to present world maps that address diverse technical and aesthetic goals.

Animated mapping is the application of animation, either a computer or video, to add a temporal component to a map displaying change in some dimension. Most commonly the change is shown over time, generally at a greatly changed scale. An example would be the animation produced after the 2004 tsunami showing how the waves spread across the Indian Ocean.

<span class="mw-page-title-main">Thematic map</span> Type of map that visualizes data

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 visualize selected properties of geographic features that are not naturally visible, such as temperature, language, or population. In this, they contrast with general reference maps, which focus on the location of a diverse set of physical features, such as rivers, roads, and buildings. Alternative names have been suggested for this class, such as special-subject or special-purpose maps, statistical maps, or distribution maps, but these have generally fallen out of common usage. Thematic mapping is closely allied with the field of Geovisualization.

The history of cartography refers to the development and consequences of cartography, or mapmaking technology, throughout human history. Maps have been one of the most important human inventions for millennia, allowing humans to explain and navigate their way through the world.

<span class="mw-page-title-main">Pictorial map</span> Map that uses pictures to represent features

Pictorial maps depict a given territory with a more artistic rather than technical style. It is a type of map in contrast to road map, atlas, or topographic map. The cartography can be a sophisticated 3-D perspective landscape or a simple map graphic enlivened with illustrations of buildings, people and animals. They can feature all sorts of varied topics like historical events, legendary figures or local agricultural products and cover anything from an entire continent to a college campus. Drawn by specialized artists and illustrators, pictorial maps are a rich, centuries-old tradition and a diverse art form that ranges from cartoon maps on restaurant placemats to treasured art prints in museums.

<span class="mw-page-title-main">Terrain cartography</span> Representation of surface shape on maps

Terrain cartography or relief mapping is the depiction of the shape of the surface of the Earth on a map, using one or more of several techniques that have been developed. Terrain or relief is an essential aspect of physical geography, and as such its portrayal presents a central problem in cartographic design, and more recently geographic information systems and geovisualization.

Critical cartography is a set of mapping practices and methods of analysis grounded in critical theory, specifically the thesis that maps reflect and perpetuate relations of power, typically in favor of a society's dominant group. Critical cartographers aim to reveal the “‘hidden agendas of cartography’ as tools of socio-spatial power”. While the term "critical cartography" often refers to a body of theoretical literature, critical cartographers also call for practical applications of critical cartographic theory, such as counter-mapping, participatory mapping, and neogeography.

<span class="mw-page-title-main">Orienteering map</span>

An orienteering map is a map specially prepared for use in orienteering events. It is a large-scale topographic map with extra markings to help the participant navigate through the course.

Planetary cartography, or cartography of extraterrestrial objects (CEO), is the cartography of solid objects outside of the Earth. Planetary maps can show any spatially mapped characteristic for extraterrestrial surfaces.

Cartographic generalization, or map generalization, includes all changes in a map that are made when one derives a smaller-scale map from a larger-scale map or map data. It is a core part of cartographic design. Whether done manually by a cartographer or by a computer or set of algorithms, generalization seeks to abstract spatial information at a high level of detail to information that can be rendered on a map at a lower level of detail.

Cartographic propaganda is a map created with the goal of achieving a result similar to traditional propaganda. The map can be outright falsified, or created using subjectivity with the goal of persuasion. The idea that maps are subjective is not new; cartographers refer to maps as a human-subjective product and some view cartography as an "industry, which packages and markets spatial knowledge" or as a communicative device distorted by human subjectivity. However, cartographic propaganda is widely successful because maps are often presented as a miniature model of reality, and it is a rare occurrence that a map is referred to as a distorted model, which sometimes can "lie" and contain items that are completely different from reality. Because the word propaganda has become a pejorative, it has been suggested that mapmaking of this kind should be described as "persuasive cartography", defined as maps intended primarily to influence opinions or beliefs – to send a message – rather than to communicate geographic information.

<span class="mw-page-title-main">Map symbol</span> Graphic depiction of a geographic phenomenon

A map symbol or cartographic symbol is a graphical device used to visually represent a real-world feature on a map, working in the same fashion as other forms of symbols. Map symbols may include point markers, lines, regions, continuous fields, or text; these can be designed visually in their shape, size, color, pattern, and other graphic variables to represent a variety of information about each phenomenon being represented.

<span class="mw-page-title-main">Cartographic design</span> Process of designing maps

Cartographic design or map design is the process of crafting the appearance of a map, applying the principles of design and knowledge of how maps are used to create a map that has both aesthetic appeal and practical function. It shares this dual goal with almost all forms of design; it also shares with other design, especially graphic design, the three skill sets of artistic talent, scientific reasoning, and technology. As a discipline, it integrates design, geography, and geographic information science.

<span class="mw-page-title-main">Proportional symbol map</span> Thematic map based on symbol size

A proportional symbol map or proportional point symbol map is a type of thematic map that uses map symbols that vary in size to represent a quantitative variable. For example, circles may be used to show the location of cities within the map, with the size of each circle sized proportionally to the population of the city. Typically, the size of each symbol is calculated so that its area is mathematically proportional to the variable, but more indirect methods are also used.

References

Citations
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  2. The orientation of the world in the African thought
  3. Watson, Clare, 'Radically Different': This Could Be The Most Accurate Flat World Map Ever Made , Science Alert, March 8, 2022
  4. "Commonly Used Map Projections" . Retrieved 8 August 2022.
  5. Ordnance Survey, Explorer Map Symbols Archived 3 April 2016 at the Wayback Machine ; Swisstopo, Conventional Signs Archived 28 May 2008 at the Wayback Machine ; United States Geological Survey, Topographic Map Symbols Archived 1 June 2008 at the Wayback Machine .
  6. Albrecht, Jochen. "Maps projections" . Retrieved 13 August 2013.
  7. Jill Saligoe-Simmel,"Using Text on Maps: Typography in Cartography"
  8. Chappell, Bill (12 April 2014). "Google Maps Displays Crimean Border Differently In Russia, U.S." NPR.org . Retrieved 6 September 2018.
  9. Wagstaff, Jeremy (23 March 2012). "Google charts a careful course through Asia's maps". Reuters . Retrieved 6 September 2018.
  10. Guanqun, Wang (19 May 2010). "China issues new rules on Internet map publishing". Xinhua News Agency . Archived from the original on 27 May 2016. Retrieved 27 July 2016.
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