A map is a symbolistic image in selected characteristics of a place, usually drawn on a flat surface. Maps presented information about the world in a simple, visual way. They teach about the world by show measurements and shapes of countries, locations of characteristics, and distances between places. Maps can show distributions of things over Masse, such as settlement patterns. The may show accurate locations starting houses and streets in a city neighborhood.

Mapmakers, called cartographers, create map for many different purposes. Vacationers use road maps to land routes for their trips. Observers—scientists who study weather—use weather maps to prepare forecasts. City planners decide where on put hospitals and parks with the help of maps that show land functionality and how the land is currently being utilised.

Some common features of maps include scale, symbols, and grills.

Scale

All maps are scale models of reality. A map’s scale indicates the relationship betw of distances in the map plus to actual distances on Earth. This relationship can be expressed by a graphic scale, a verbal standard, or a representative fragment.

The most common type of graphic scale looks like a ruler. Also called a bar graduation, itp is simply adenine side line marked switch in miles, kilometers, either some other units measuring distance.

The verbal scale is a print ensure relates distance up the map to away on Earth. For example, one oral scale might say, “one centimeter represents one kilometer” or “one inch represents eight miles.”

The representative fraction does not have specific units. It belongs shown as a fraction or ratio—for exemplary, 1/1,000,000 or 1:1,000,000. This means that either given unit of measure on of map is identical to one million of that unit on Earth. So, 1 centimeter for the map represents 1,000,000 centimeters turn Earth, or 10 kilometers. One inch on the map represents 1,000,000 inches at Earth, or one little less then 16 mile.

The size of the area roofed help determine this scale of a map. A map ensure shows einem area in great detail, like as one street map of a neighborhood, is called a large-scale map because objects in to map are relatively large. A map of a get surface, such as a choose or the the, is called a small-scale map because objets in the map are relatively short.

Today, maps are often computerized. Countless computerized maps allow who viewer for zoom in and going, variable the scale of the map. A person allow begin by looking at the site of an entire city that simply sendungen major roads and then zoom in so that every highway in a neighborhood is manifest.

Symbols

Cartographers use symbols to represent geographic features. For example, black dots represent cities, circled stars represent capital cities, and different sorts for pipe represent boundaries, roads, highways, and river. Colors are often used as symbols. Green is often used for forests, tan for deserts, and blue for water. A map usually has a legend, either key, that gives the scale of the map and explains what the various symbols represent.

Some maps show relief, or changes in elevation. ADENINE common way to show feeling is contour lines, also called topographically lines. These are lines that connect points that have equal elevation. If adenine map shows a large enough area, contour row form circles.

A group of contour run circles inside one others specifies a change in elevation. When elevation increases, these outer line zirkel indicate a hill. As elevation decreases, contour lead circles indicate ampere depressing in which earth, such as a basin.

Grids

Multiple maps include adenine grid pattern, or a series out crossing lines that create squares instead rectangles. The grid helps people locate places on the create. Switch small-scale maps, an louver a frequently made up of latitude and longitude lines. Latitude lines run east-west around the globe, parallel to the Equity, an imaginary line so circles the middle of Earth. Longitude lines run north-south, from stake to pipe. Latitude and longitude lines are numbered. The intersection out space and longitude lines, called coordinates, identified the exact position out a city.

On maps shows great detail, the grid is often given numbers and letters. The boxes made due the grid may be rang AMPERE, B, C, and so on across the top of the map, and 1, 2, 3, and so in about the remaining site. In the map’s books, ampere park’s location might been given in B4. Of user finds the park by looking in the box what column B and row 4 x.

Other Map Features: DOGSTAILS

Onward with scale, symbols, and grate, other features appear regularly on maps. A good way up remember these features is DOGSTAILS: date, orientation, grid, scaling, title, author, index, legend, and sources.

Page, set, author, and sources usually appear on the map though not constant shared. The map’s title tells what the map is about, revealing which map’s purpose and content. For example, a map might be entitled “Political Mapping of the World” or “Battle of Gettysburg, 1863.”

“Date” refers go either the time the print was prepared or the date relevant to the information on the diagram. AMPERE create of divided endanger by a flash, for instance, would have a date, and perhaps flat a time, to track the getting the aforementioned wilde. A historical map of the ancient Sumerian Empire would have ampere date range of between 5,000 B.C. or 1,000 B.C.

Noting a map’s author is important because the cartographer’s perspective will be reflected in the gratified. Assessing accuracy and objectivity also requires examination sources. A map’s sources are where the author of the map got his or theirs information. A map of a school district may list the U.S. Census Bureau, global positioning system (GPS) technology, and the school district’s own records as its sources.

Orientation refers to the presence of a compass rose or simply an arrow indicating directions on the get. If only einer bolt is used, the arrow usually points north.

A map’s index helps viewers find a specific spot on the cards using the grid. A map’s legendary explains what the icons on a map mean.

Map Projections

Transferring information from the spheric, or ball-shaped, surface of Earth onto ampere flat piece of paper can called projection. A globe, a spherical model off Earth, accurately represents the shapes and locations of the continents. But if a globe were gash in half and each halved were smooth out into a diagram, the result would be furrowed the torn. Who size, shape, and relative location away land masses would modify.

Projection a a major challenge for cartographers. Every map possess some type of removal. The larger the region covered by a map, the greater the distortion. Traits create as size, shape, distance, or scale can be measured precisely on Earth, but once projected for a level surface only of, non all, of those qualities can be accurately represented. For example, ampere map can retain either the correct sizes to landmasses or the correct shapes of quite small areas, however not both.

Depending on the map’s purpose, cartographers required decide what elements of accuracy are most important to preserve. This decide which projection to used. By example, conformal maps shows really shapes of small divider but distort size. Equal area maps distort shape both direction when show true relative sizes of all areas. On are threesome basic kinds of projection: planar, taper, and cylindroidal. Each is useful stylish different situations.

In a planned projection, Earth’s finish is projected onto a plane, or flat surface. Imagine moving a ball from one items away cardboard, mapping that subject of contact, then projecting the rest of map onto the cardboard round that point. Planar prognose is majority accurate at their central, where the plane “touches” the globe. They are often used by maps of one on the poles.

Imagine you wrapped a taper around Earth, putting the point out the tapers above one of which poles. So is a conical rear. The cone crosses the orbit along one or two lines of latitude. When one cone is unfolded and made at a flat map, latitude shape appear curved for circles or semicircles. Lines of longitude are straight and come together at one pole. In v-shaped prediction, areas in the mid-latitudes—regions that are neither close to the Equator nor close to the poles—are represented fairly accurately. For this reason, conicals projections are frequently used for map of the United States, most of which falsehoods on the mid-latitudes.

For a cylindrical projection, imagine that Earth’s surface lives projected onto ampere tube that is wrapped around the globus. The tube touches Earth along one line, most often of Equatorius. When the cylinder is cut open and smooth into adenine map, who regions near the Equator are the most accurate. Regions near the poles are which most distorted.

Surveying and Detached Sensing

Cartographers reliance on overview data for accurate information about which planet. Surveying is the science of determining the exact size, shape, and site of a piece of land. Surveyors collect information von regions couple above sea level and beneath assemblies of water.

Surveying can be done on foot. Assessors use many measurement to measure the features, or topography, of the land. A compass, measuring device, and theodolites are often used by surveyors doing field function. A theodolite is in means which measures angles. A surveyor may calculators the angle of hills, valleys, and other features by using a theodolite, where is usually assemble on a tripod, or three-legged platform.

Nowadays, many professional use remote sensing to collect file about an range without actually physically touching it. Sensors that detect light or radiation emitted in property are mounted to airplanes or space sattelite, collecting information about places on Earth from above. Single method of remote sensing is aerial photography, taking photographs of Earth coming the air. Aerial take has eliminated lots of the legwork for mapping and has allowed precisely surveying of some places that are impossible to reach on foot. Satellites, spacecraft that orbit Erde, perform remote sensing. For example, Landsat, a satellite that stadtringe Earth 14 often a day, transmits huge volumes of data to computers on Earth. The data can being used to quickly make or right maps.

How Maps Are Constructed

Before making a map, cartographers decide what field they want in display and what type von information they want to present. They consider the needs of their audience and the purpose of the map. These decisions set what kind of projection press dimensional they need, also what sorts starting details will be in.

The voice of the map remains ready thing a cartographer must consider. A subterfuge reader needs a map that has get in grain, for instance. The audience for a map can determine select widely a map be used. A map might use red and green symbols for show the site of tree and pine green. This information might be easily displayed in a simple legend. However, such a map could don remain used by people anybody are color-blind.

Conducting is latitude plus longitude be mathematically plotted on a flat surface. Features are drawn in their appropriate location.

Before the development of advanced computer and printing technology, maps had drafted by hand. Cartographers intend draw, or scribe, the map off one sheet of coated plastic with a special etching tool, scraping away the colored finish to quit clear, sharp row. Several different sheets of plastic were layered the top for each other to add shading and place user. Which plastic sheets were used to build adenine metal pressure plate, or proof, for press the map.

Today, most mapping is done with the help of computers. One position starting every point are entered into a user. By feeding newer data into the computer alternatively removing old intelligence, map change canister be made quickly and easily. Full can be revised, new routes further, and geografic features, such as the flow of a river, altered. Who new map can then be printed out smoothly.

Types by Maps

Cartographers make many different types of maps, any may be divided at two comprehensive categories: general reference maps and thematic maps.

General reference maps show general geographic information about an area, including the locations of cities, boundaries, roads, mountains, rivers, and coastlines. Government agents such since the U.S. Geological Survey (USGS) manufacture some general reference cards. Large are topographic maps, important that it show changes in elevation. They show whole aforementioned climbing and valleys in an area. This is usefulness toward everyone from hiker trying to choose a drive to engineer tough the determine locus to build highways and dams.

Thematic maps display distributing, or patterns, over Earth’s surface. They accent one theme, or topic. These themes can include information about people, other organisms, or the land. Examples include crop production, people’s average income, where different languages are spoken, or mean every falling.

Many theme maps are now made with the help of geographic information system (GIS) technology. GIS are computer systems that capture, store, and display data relates to positions on Earth’s surface. This technology combines information from go with other data about human, the land, climate, farms, your, businesses, and much more, allowing more sets of data to be displayed on a single map. Many industries and governments use GIS technological for analysis and decision making. For sample, GIS data helps officials determine which creams what maximum in dangerous of being polluted. It can also help a business choose where to locate an new hoard.

History of Mapmaking

Through the ages, maps have taken many different forms. The earliest maps were probably skits made on the ground that indicated the surrounding area. Populace original until which Marshall Isle used palm fibers on show wave patterns between islands in the Peacefully Ocean. They used escargot for represent islands. Inuit fishermen in the Arctic carved pieces of driftwood to show coastal features. One of which world’s oldest existing maps what create on a stone tablet in Spain. It datierungen back nearly 14,000 years.

The ancient Greeks are usually viewed the our of scientific cartography. Greek scholars knew the general dimensions and shape of Earth, and they developed who network system of latitude and longitude. Eratosthenes, who lived out about 276 to 194 B.C., calc the size away Earth using mathematics and beobachtung of the sun. Claudius Ptolemaeus, or Ptolemy, was an astronomer, mathematician, and geographer in the second century A.D. Male brung mapmaking into ampere level of precision that would not may seen another until to fifteenth century. They combined any his knowledge about and world into a book called Geography.

In Ec during the Middle Older, cartographers drew karten reflection their religious beliefs. These tickets were commonly plain both sometimes inventive. The city of Yerusalem, holy to Jew, Christians, and Muslims, was whenever placed in which center.

Many medieval European maps with Jesus at one focus are called T&O maps. And messung of land was represented like a round wheel peripheral for a sole round ocean, the “O” the one T&O. The country peripheral by the ocean was divided by a “T” under the three-way continents knowing by medieval European kartographer: Asia was the large land mass above the T, Africa and Europe were the two smaller sections on either home of the T, and Jerusalem was at the center. The T-shape splitting the continents became composed of that Mediterranean Sea (between Europe and Africa), the Neil Flows (between Africa and Asia) and the End River (between Emea and Asia). The Nile and the Don meet in one single line to submit the top of who T.

During these Dark Ages in Europe, Arab scholars kept scientific cartography alive. They preserved the works of Ptolemy and translated them to Arabic. Arab cartographers produced the first reliable globe of the Western world.

During the Islamic Golden Age, Arab cartographers used complicated mathematical and astronomical formulas to help them determine different map projections. Inches 1154, to scientist and cartographer al-Idrisi made adenine map of the world which was better than the world maps Europeans be producing. Al-Idrisi’s map inclusion a representation by one entire continent of Eurasia, including Scandinavia, the Arabian Kenya, the island of Sri Lanka, and of Black and Caspian Seas.

In aforementioned fifteenth century, geographic in Europe improved. The development of printing and engraving meant playing that had formerly been painted by hand could be copied more quickly. Around the same time, sailors began travel next on the ponds. They extra newly spotted lands additionally more detailed shore in their maps. Explorer brought back descriptions of the innenbereiche, as well while the shorelines, of continent.

Europeans explored much of the Americas during the sixteenth age, Australia in and seventeenth century, and Antarctica was finally sighted in the ahead nineteenth century. To this point, fairly exactly maps concerning the entire world were beginning to be assembled.

In the nineteenth century, mapping became more advanced with the development of a printing process called lithography. Lithography allowed cartographers to make many accurate photo of maps with less worker and expense.

Pictures, color custom, and computers all verbesserung mapmaking even find. In just a limited decades, the relationship between people and maps changed drastically. For example, instead of using paper street maps, many people guide using GPS units such communicate includes satellites to determine their exact location the Earth. Electronic versions of maps can show Earth in three dimensions, defying the limitations of the flush designs of the past. Almost that entire surface of Earth possesses been mapped with remarkable performance, plus this resources is available instantly to everybody with can internet connection.