What is the significance of a physical map

Many computerized maps allow the viewer to zoom in and out, changing the scale of the map. A person may begin by looking at the map of an entire city that only shows major roads and then zoom in so that every street in a neighborhood is visible.

Symbols Cartographers use symbols to represent geographic features. For example, black dots represent cities, circled stars represent capital cities, and different sorts of lines represent boundaries, roads, highways, and rivers.

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 , or key, that gives the scale of the map and explains what the various symbols represent. Some maps show relief, or changes in elevation. A common way to show relief is contour lines, also called topographic lines.

These are lines that connect points that have equal elevation. If a map shows a large enough area, contour lines form circles. A group of contour line circles inside one another indicates a change in elevation. As elevation increases, these contour line circles indicate a hill.

As elevation decreases, contour line circles indicate a depression in the earth, such as a basin. Grids Many maps include a grid pattern, or a series of crossing lines that create squares or rectangles.

The grid helps people locate places on the map. On small-scale maps, the grid is often made up of latitude and longitude lines. Latitude lines run east-west around the globe , parallel to the Equator , an imaginary line that circles the middle of the Earth.

Longitude lines run north-south, from pole to pole. Latitude and longitude lines are numbered. The intersection of latitude and longitude lines, called coordinates , identify the exact location of a place. On maps showing greater detail, the grid is often given numbers and letters. The boxes made by the grid may be called A, B, C, and so on across the top of the map, and 1, 2, 3, and so on across the left side.

The user finds the park by looking in the box where column B and row 4 cross. Title, date, author, and sources usually appear on the map though not always together. A map of areas threatened by a wildfire, for instance, would have a date, and perhaps even a time, to track the progress of the wildfire. A historical map of the ancient Sumerian Empire would have a date range of between 5, B. Assessing accuracy and objectivity also requires checking sources.

A map of a school district may list the U. Orientation refers to the presence of a compass rose or simply an arrow indicating directions on the map. If only an arrow is used, the arrow usually points north. Map Projections Transferring information from the spherical , or ball-shaped, surface of Earth onto a flat piece of paper is called projection. A globe, a spherical model of Earth, accurately represents the shapes and locations of the continents.

But if a globe were cut in half and each half were flattened out into a map, the result would be wrinkled and torn. The size, shape, and relative location of land masses would change. Projection is a major challenge for cartographers. Every map has some sort of distortion.

The larger the area covered by a map, the greater the distortion. Features such as size, shape, distance, or scale can be measured accurately on Earth, but once projected on a flat surface only some, not all, of these qualities can be accurately represented.

For example, a map can retain either the correct sizes of landmasses or the correct shapes of very small areas, but not both. This determines which projection to use. For example, conformal maps show true shapes of small areas but distort size. Equal area maps distort shape and direction but show true relative sizes of all areas.

There are three basic kinds of projections: planar, conical, and cylindrical. Each is useful in different situations. Imagine touching a globe with a piece of cardboard, mapping that point of contact, then projecting the rest of map onto the cardboard around that point. They are often used for maps of one of the poles. Imagine you wrapped a cone around Earth, putting the point of the cone over one of the poles.

That is a conical projection. The cone intersects the globe along one or two lines of latitude. When the cone is unwrapped and made into a flat map, latitude lines appear curved in circles or semicircles.

Lines of longitude are straight and come together at one pole. In conical projection, 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, conical projections are often used for maps of the United States, most of which lies in the mid-latitudes. The cylinder touches Earth along one line, most often the Equator.

When the cylinder is cut open and flattened into a map, the regions near the Equator are the most accurate. Regions near the poles are the most distorted. Surveying and Remote Sensing Cartographers rely on survey data for accurate information about the planet. Surveying is the science of determining the exact size, shape, and location of a piece of land. Surveyors gather information from regions both above sea level and beneath bodies of water. Surveying can be done on foot. Surveyors use many instruments to measure the features, or topography , of the land.

A compass, measuring device, and theodolites are often used by surveyors doing field work. A theodolite is an instrument that measures angles. A surveyor may calculate the angle of hills, valleys, and other features by using a theodolite, which is usually mounted on a tripod , or three-legged platform. Today, many surveyors use remote sensing to collect data about an area without actually physically touching it.

Industrial mineral maps show information about industrial mineral mines like stones, aggregates, clay, they include commodity being mined, type, size of mines in acreage, operator details. They will also show metallic minerals waste management in the mine areas etc. Coal mines maps show information on coal mines and mined areas. They include information such as mine status mine owner type, seam thickness, they can include overlay information on oil and gas activity in the region.

These are maps that show abandoned mines by region, they show individual sites, the commodity that was mined there, date and method of closure, cost of closure, depth and size of mine shafts, whether coal was present, etc.

Aggregate resources mines Maps. Aggregate resources mines maps show sand and construction aggregate mining operations, they include information on location, operators, material mined, mining dates total are and reclaimed area. Fault activities interactive maps allow users to identify locations and classifications of geological fault lines and recent activities on each fault segment surface rupture areas and whether or not faults are visible on the surface. Volcanoes and Volcanic Activities Maps.

Volcanic and volcanic activity maps are GIS geological survey maps that show current alerts of volcanoes by location and activity level. They show volcano status by color levels, green being normal, yellow advisory, orange watch, and red warning. Earthquake hazard zone maps are interactive maps threat detail the risk of earthquake-related hazards in different areas, they show fault lines, landslide zones, liquefaction zones, they also include areas that have not yet been evaluated.

Carbon dioxide storage maps detail information on storage assessment for sedimentary basins and includes potential storage, individual formations, and detailed stratigraphic charts. Geohazards maps show geohazards like earthquakes, active faults, historical epicenters, expected shaking and liquefaction hazards, tsunami, inundation, volcanoes, landslides, floods, and coastal erosions. Tsunami evacuation information Maps. Tsunami evacuation maps give information about tsunami evacuation procedures by locality which includes evacuation zones, evacuation routes, evacuation assembly areas local landmarks.

Hurricanes path maps track hurricane and tropical cyclones around the world and have information that date as far back as They show category, wind speed and a minimum pressure of each hurricane at different points and much more.

Landslide maps display landslide locations and reports and vary both historically and recent landslides. Physical maps show the location of recreational parks including game parks, they show vegetation, fun activities, and much more.

Elevation maps depict geographical elevations in different geographical zones in relation to the sea level. Town and municipalities maps show various towns and their municipalities and all related features including population density, road network emergency facilities, etc.

Cities maps show different cities of the world their positions physical features infrastructure transportation network streets buildings and locations. Political boundaries maps are physical maps that show the boundaries of different administrative zones in relation to population and availability of services. Geographical planning maps show future plans of a region in relation to its geopolitical location, geographical features availability of natural resources like water, etc.

Civil engineering maps show civil works in urban centers, bridges, waterways, roads, tramways, and any other man-made features. Large scale architectural works encompass large tracts of land. Architectural maps help locate every component of the works.

The geological maps show, different colors for different types of rocks to help prospectors and developers understand the [physical location. Mountain maps give locations of all the major mountains in the world, they show elevation, geographical features, wildlife, vegetation, topography, snow and ice conditions and much more. Physical maps help us know ourselves in relation to our physical environment they are a rich source of information to everybody. Notify me of follow-up comments by email.

Notify me of new posts by email. This site uses Akismet to reduce spam. Learn how your comment data is processed. Maps serve two map functions; they are a spatial database and a communication device.

The science of making maps is called cartography. Basic map characteristics tell the reader where an object is location and what the object is its attributes. A map is an image of an area, usually of the Earth or part of the Earth. A map is different from an aerial photograph because it includes interpretation. If a map is on a piece of paper or a computer screen, it has to be projected. Maps contain lots of information. Most maps will have the five following things: a Title, a Legend, a Grid, a Compass Rose to indicate direction, and a Scale.

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.

It could be hand drawn or printed. It helps us identify the places and locations within an area helping us to navigate from one place to another. They are- title, direction, legend symbols , north areas, distance scale , labels, grids and index, citation — which make it easier for people like us to understand the basic components of maps.

Physical Maps — illustrate the physical features of an area, such as the mountains, rivers and lakes. Topographic Maps — include contour lines to show the shape and elevation of an area. They can also be used to show elevation, land use, infrastructure, and many other man-made features. Physical maps that show boundaries are also known as political maps. Physical map: A map of the locations of identifiable landmarks on chromosomes.

Physical distance between landmarks is measured in base pairs. The physical map differs from the genetic map, which is based purely on genetic linkage data. The definition of a physical map is a depiction of the geographic features of an area. An example of a physical map is an aerial view South America showing the forests in green, the mountains in gray, the streams in blue and the oceans in deep blue.

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. The roads and city streets can faintly be seen through the translucent colors of the geologic units.

The western portion of the map is underlain by Quaternary sediments, while the eastern portion is underlain by folded and intensely faulted bedrock. Dotted lines show the probable traces of faults buried below the Quaternary sediments. Geologic maps of this area can be important first tools in conducting an earthquake hazard assessment. Graymer, U. 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 Cross-Section illustrating the subsurface structure of rocks in the map area above.

This cross-section represents a southwest-northeast slice through the map area, showing folds, faults, a sediment lens and a view of the creeping portion of the Hayward Fault. 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. They do the fieldwork, prepare the maps, publish them, and offer them to the public in digital and paper formats. Zip Code Map: This map shows some of the zip codes in the state of Connecticut. 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. Weather Map showing projected high temperatures for Sunday, July 29, This is one of the many types of weather maps prepared by the National Weather Service of the United States and published online for anyone to use.

Visit their website at weather. 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.

Species Distribution Maps show where certain plant or animal species can be found. This map shows where different types of bears live in North America. The area normally inhabited by a plant or animal species can be mapped.

These maps are made by compiling the locations where qualified people have repeatedly observed that species in the wild.

The resulting maps show by color or pattern the geographic area where that species is encountered. These maps are known as "species distribution maps" or "geographic range maps. That map was made by overlaying the geographic ranges of black bears, grizzly bears, and polar bears on a single map. Because the geographic ranges of these three species overlap, it is possible to be in an area where a person might encounter one, two, or even three different species.

There are also areas of North America where a person would not expect to encounter a bear. The resulting map is shown in the accompanying image. Income Map: Map showing the median household income of the United States using individual counties as enumeration units. Map by the United States Census Bureau. Click to enlarge. 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.