Types of Maps
There are thousands of types of maps. Here are some of the most popular.
Article by: Hobart M. King, Ph.D., RPG
and Map Junkie
|Different Types of Maps|
Millions of Unique Maps
Millions of unique maps are in use throughout the world. Most of these maps can be placed into one of two groups: 1) reference maps; and, 2) thematic maps.
Reference maps show the location of geographic boundaries, physical features of Earth, or cultural features such as places, cities, and roads. Political maps, physical maps, road maps, topographic maps, time zone maps, geologic maps, and zip code maps are all examples of reference maps. A variety of reference maps have been created for almost every country of the world.
Thematic maps show the variation of a topic (the theme) across a geographic area. Weather maps showing daily high temperatures across the United States are familiar examples of a thematic map. They are made by starting with a reference map of the United States. Then temperature data is plotted atop of the reference map using colors to communicate the temperature forecast. Income maps and resource maps are other types of thematic maps.
In the sections of this article below, you will find several examples of commonly used reference maps and thematic maps.
|Political Boundary Maps|
“Political maps” are among the most widely used reference maps. They are mounted on the walls of classrooms throughout the world. They show the geographic boundaries between governmental units such as countries, states, and counties. They show roads, cities and major water features such as oceans, rivers and lakes.
Political maps help people understand the geography of the world. They are usually the first type of map that students are introduced to in school. They are also known as “reference maps” because people refer to them again and again as they have questions.
Political maps are often printed on paper or another physical medium, but they can also be produced in digital form, suitable for viewing online. Every day millions of people visit search engines to find political reference maps. Some of the most popular searches are for “united states map”, “world map”, “europe map”, and “florida map”.
Thousands of different political reference maps have been prepared to show the current geography of the United States. There are maps of the entire nation, maps for each of the 50 states, maps of the 3142 counties (parishes in Louisiana, and boroughs in Alaska) that make up the states. Most counties, boroughs and parishes are further subdivided into even smaller political units. An incredible number of political maps have been prepared just to display the geography of the United States.
The maps most commonly seen in classrooms and offices are political maps of the world, countries and continents. They are often annotated with push pins, sticky notes, photographs, marker flags and string to show the travels of a family, locations of a business, or other locations and activities worthy of display.
Physical maps are designed to show the natural landscape features of Earth. They are best known for showing topography, either by colors or as shaded relief. Physical maps often have a green to brown to gray color scheme for showing the elevation of the land. Darker greens are used for near-sea-level elevations, with the color grading into tans and browns as elevations increase. The color gradient often terminates in shades of gray for the highest elevations.
Rivers, lakes, seas and oceans are usually shown in blue, often with a light blue color for the most shallow areas and darkening in a gradient or by intervals for areas of deeper water. Glaciers and ice caps are shown in white colors.
Physical maps usually show the most important political boundaries, such as state and country boundaries. Major cities and major roads are often shown. This cultural information is not the focus of a physical map, but it is often included for geographic reference and to increase the utility of the map for many users.
|Digital Road, Street and Highway Maps|
Road, Street and Highway Maps
The digital mapping revolution caused an explosion of map creation in the 1990s. In 1996, MapQuest, the first popular online mapping service, allowed anyone with internet access the ability to create customized maps of almost any location in the United States.
Within a few months, millions of people had become “cartographers”. They were soon producing more unique maps in a single day than had been created during the entire history of paper cartography!
Today, Google Maps is the world's most popular online mapping system. In addition to maps, the service also provides travel route directions. It can create directions for people who are driving, taking public transportation, walking, cycling or taking a plane.
Billions of unique maps, millions of travel routes, and millions of street views are created each day with Google Maps. It is the first place millions of people go to plan any type of travel.
Google has another product named "Google Earth" that allows people to view streets, roads and satellite images within a single interface. Google Earth is a free download - the software installs on your computer and fetches the image directly from the Google Earth server.
Finally, for people who want printed maps, the DeLorme Atlas & Gazetteer is a series of books that contain state-wide map coverage for individual states (or pairs of small adjacent states). The maps present a combination of road, topography, cultural and recreational information. These "hybrid maps" are a favorite of people who work and play outdoors in rural areas.
Topographic maps are reference maps that show the shape of Earth’s surface. They usually do this with lines of equal elevation known as “contour lines”, but elevation can also be shown using colors (second map), color gradients, shaded relief and a number of other methods.
Topographic maps are frequently used by hunters, hikers, skiers, and others seeking outdoor recreation. They are also essential tools of the trade for geologists, surveyors, engineers, construction workers, landscape planners, architects, biologists and many other professions - especially people in the military.
Topographic maps also show other important natural features such as lakes, rivers and streams. Their locations are determined by topography, making them important natural elements of topographic maps.
Important cultural features are also shown on topographic maps. These include roads, trails, buildings, place names, bench marks, cemeteries, churches, schools and much more. A standardized set of special symbols has been developed for this use.
Topographic maps have traditionally been printed on large sheets of paper with their four boundaries being lines of longitude and latitude. The United States Geological Survey is the most widely known organization for producing them. They produce a series of 7.5-minute topographic maps covering most areas of the United States (a 7.5-minute map shows an area that is 7.5 minutes of longitude by 7.5 minutes of latitude). These maps and maps of many other scales are available from USGS in both print and digital form.
Commercial publishers of topographic maps include the DeLorme Atlas (paper maps in books with state-wide coverage) and MyTopo (a source of digital and paper maps in traditional topographic and topophoto formats - we are affiliates of MyTopo and receive a commission on referred sales).
Time Zone Maps
Time zones are regions of the world where people set their clocks to display the same time of day. This synchronization of time has many commercial, navigational, and social benefits.
By international agreement there are 24 time zones around the world. These 24 zones are shown in the accompanying time zone map. In each of these zones, 12:00 noon occurs at the approximate time of the solar mid-day. The actual solar noon occurs a little earlier in the east side of the time zone and a little later in the west. This variation is caused by Earth's rotation.
Time zone maps are reference maps that people use to determine the time in different parts of the world. For example if a person in New York City wants to phone a person in Los Angeles, he can look at a time zone map and determine that New York City time is three hours ahead of Los Angeles time. This helps people to avoid placing calls outside of business hours and helps people in different time zones schedule meetings and phone calls at mutually agreeable times. Time zones are usually superimposed on a political map of the world or a map of a large single country such as the United States.
Geologic maps show the types of rocks and sediments present immediately below the surface of a geographic area. Sediment cover is shown in shades of yellow, and rock units are shown in a variety of colors, often based upon their lithology. Rock unit contacts, faults, folds, and strike and dip measurements are plotted in black.
Geologic maps are important data sources for many types of work. Certain types of rock are used for construction materials, and a geologic map shows where they are located at the surface. Other types of rock might contain valuable minerals, and a geologic map can be used as a preliminary tool for deciding where to drill or prospect.
Areas near volcanoes might be underlain by lava flows, lahar deposits, pyroclastic flows or other volcanic products. Geologic maps can be used to conduct a preliminary volcanic hazard assessment of an area.
Construction projects require good foundation materials and sources of crushed stone and other materials. Geologic maps can be used for the preliminary work of identifying potentially stable sites near economic sources of suitable construction materials.
|Geologic Map Cross-Section|
Geologic maps are made by geologists in the field who identify, sample, and measure the rocks. Because rocks are not exposed in all locations - especially in areas with heavy vegetation - they are often based upon fragmentary information. This fragmentary information can be supplemented when construction projects, landslides, stream erosion and other events expose rock beneath previously unobserved areas. As a result, geologic maps can be refined and updated as new information is obtained.
Most geologic maps are usually accompanied by at least one cross-section that illustrates what is expected to be seen if a “slice through the Earth” was cut across the map area. These cross-sections illustrate the geologic structures inferred by mapping the rocks and sediments above.
In the United States, most geologic maps available for public use or purchase are prepared by the United States Geological Survey and the State Geological Surveys. They do the fieldwork, prepare the maps, publish them, and offer them to the public in digital and paper formats.
|Zip Code Map|
Zip Code Maps
Zip Code Maps are maps that show the approximate boundary of zip code areas used by the United States Postal Service. They are usually plotted over a base map that shows the roads and streets within the zip code area.
The United States Postal Service assigns zip codes for a section of a street, a collection of streets, an establishment, a structure, a group of post office boxes, or the area serviced by a single post office for the delivery of mail. Rather than consisting of geographic areas, zip codes are more in conformance with a group of mail delivery routes. In sparsely populated areas, a single zip code can cover many square miles, but in cities a zip code can be assigned to a single building or to an organization with a campus of buildings.
Businesses make valuable use of zip code maps by matching them to zip code tabulation data compiled by the United States Census Bureau. This data characterizes the population within a zip code by age, gender, race, national origin, income, housing, and much more. Companies can use this information to determine if they want to market to people within that zip code and how they want to market. They can also coordinate their mailings with the United States Postal Service to deliver their marketing materials to zip codes where demographic data suggests a high density of potential customers.
People use an incredible number of weather maps. They are used to show predicted temperatures, predicted precipitation, storm warnings of various kinds, wind speed and direction, chance of precipitation, type of precipitation, snow accumulation, frost prediction and many other aspects of weather.
All of these weather maps are continuously updated to communicate the most current information. They are the world's most frequently consulted thematic maps. Weather maps are presented in newspapers, television programs and especially on websites. Delivering weather maps on websites and through web apps gives people around the world instant access to weather information.
Many weather maps are animated maps that show historical or projected changes in the weather. These are extremely useful for people who need to know how changes in weather will impact their travel, workday, recreation, and many other plans.
Income maps are a very common type of thematic map. They show variations of income across a geographic area. The standard mapped variable for an income map is median household income.
Income tends to be highly geographic because rural portions of a state or country often have lower median household income than urban areas. Within urban areas, income can also be highly variable because neighborhoods tend to be populated by people with similar income levels.
The United States Census Bureau is a regular producer of income maps for the United States and individual states. After each major census, the Bureau updates its set of income maps and makes them available to the public. The Census Bureau also makes "change in income maps". These show which geographic areas have experienced economic growth or economic decline over a specific time interval.
Thematic maps are often made to communicate the geographic distribution of natural resources. These maps might show countries with the highest diamond production or the geographic extent of an oil or gas field. The map shown here illustrates the geographic pattern of solar generating capacity for the United States.
Resource maps are important because they help governments understand their natural resource assets and the natural resource assets of their allies and potential enemies. Resource maps help mining companies target their exploration efforts. They are also important for assessing the transportation opportunities and problems associated with the distribution of resources and the location of where they are consumed.
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