PLANE TABLE METHOD OF MAP MAKING

PLANE TABLE METHOD OF MAP MAKING

PLANE TABLE METHOD 01

PLANE TABLE METHOD 02

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TRIANGULATION METHOD OF MAP MAKING

TRIANGULATION METHOD - 01

TRIANGULATION METHOD - 02

TRIANGULATION METHOD – 03

TRIANGULATION METHOD OF MAP MAKING

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MAP COLOURS

Map Colors

The Role of Colors on Maps

By Matt Rosenberg

Cartographers utilize color on a map to represent certain features. Color use is often consistent across different types of maps by different cartographers or publishers. Map colors are (or should be, for a professional looking map) always consistent on a single map.

Many colors used on maps have a relationship to the object or feature on the ground. For example, blue is almost always the color chosen for fresh water or ocean (bust blue may not just represent water).

Political maps, which show more human created features (especially boundaries), usually use more map colors than physical maps, which represent the landscape often without regard for human modification.

Political maps will often use four or more colors to represent different countries or internal divisions of countries (such as states). Political maps will also use such colors as blue for water and black and/or red for cities, roads, and railways. Political maps will also often use black to show boundaries, differing the type of dashes and/or dots used in the line to represent the type of boundary – international, state, or county or other political subdivision.

Physical maps commonly use color most dramatically to show changes in elevation. A palette of greens is often used to display common elevations. Dark green usually represents low-lying land with lighter shades of green used for higher elevations. In the higher elevations, physical maps will often use a palette of light brown to dark brown to show higher elevations. Such maps will commonly use reds or white or purples to represent the highest elevations on the map.

With such a map that uses shades of greens, browns, and the like, it is very important to remember that the color does not represent the ground cover. For example, just because the Mojave Desert is shown in green due to the low elevation, it doesn’t mean that the desert is lush with green crops. Likewise, the peaks of mountains shown in white does not indicate that the mountains are capped in ice and snow all year long.

On physical maps, blues are used for water, with darker blues used for the deepest water and lighter blues used for more shallow water. For elevations below sea level, a green-grey or red or blue-grey or some other color is used.

Road maps and other general use maps are often a jumble of color. They use map colors in a variety of ways…

• Blue – lakes, rivers, streams, oceans, reservoirs, highways, local borders
• Red – major highways, roads, urban areas, airports, special interest sites, military sites, place names, buildings, borders
• Yellow – built-up or urban areas
• Green – parks, golf courses, reservations, forest, orchards, highways
• Brown – deserts, historical sites, national parks, military reservations or bases, contour (elevation) lines
• Black – roads, railroads, highways, bridges, place names, buildings, borders
• Purple – highways, (also used on U.S.G.S. topographic maps to represent features added to the map since the original survey)

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CONTOUR LINES

Contour lines

A line on a map that joins points of equal elevation.

They can be any colour chosen by the map maker. OS maps use an orangy brown.

CLICK THE FOLLOWING LINK TO GET TO KNOW MORE ABOUT CONTOUR LINES

Contour lines

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SCALE & TYPES OF SCALES IN MAP

Map Scale – Measuring Distance on a Map

Measuring Distances on a Map: Map Scale

By Matt Rosenberg

A map represents a portion of the earth’s surface. Since an accurate map represents the land, each map has a “scale” which indicates the relationship between a certain distance on the map and the distance on the ground. The map scale is usually located in the legend box of a map, which explains the symbols and provides other important information about the map. A map scale can be printed in a variety of ways.

A ratio or representative fraction (RF) indicates how many units on the earth’s surface is equal to one unit on the map. It can be expressed as 1/100,000 or 1:100,000. In this example, one centimeter on the map equals 100,000 centimeters (1 kilometer) on the earth. It also means that one inch on the map is equal to 100,000 inches on the land (8,333 feet, 4 inches or about 1.6 miles). Or even 1 paperclip on the map is equal to 100,000 paperclips on the ground. Other common RFs include 1:63,360 (1 inch to 1 mile) and 1:1,000,000 (1 cm to 10 km).

A word statement gives a written description of map distance, such as “One centimeter equals one kilometer” or “One centimeter equals ten kilometers.” Obviously, the first map would show much more detail than the second because one centimeter on the first map covers a much smaller area then on the second map.

The first two methods of indicating map distance would be ineffective if the map is reproduced by a method such as photocopying and the size of the map is modified. If this occurs, and one attempts to measure an inch on the modified map, it’s not the same as an inch on the original map.

A graphic scale does solve this problem because it is simply a line marked with distance on the ground which the map user can use along with a ruler to determine scale on the map. In the U.S., a graphic scale often includes both metric and U.S. common units. As long as the size of the graphic scale is changed along with the map, it will be accurate.

Maps are often known as large scale or small scale. A large scale map refers to one which shows greater detail because the representative fraction (e.g. 1/25,000) is a larger fraction than a small scale map which would have an RF of 1/250,000 to 1/7,500,000. Large scale maps will have a RF of 1:50,000 or greater (i.e. 1:10,000). Those between 1:50,000 to 1:250,000 are maps with an intermediate scale. Maps of the world which fit on two 8 1/2 by 11 inch pages are very small scale, about 1 to 100 million.

scale

scale, in cartography, the ratio of the distance between two points on a map to the real distance between the two corresponding points portrayed. The scale may be expressed in three ways: numerically, as a ratio or a fraction, e.g., 1:100,000 or 1/100,000; verbally, e.g., “one inch to one mile” (not “one inch equals one mile”); and graphically, by marking distances on a sample line. The last method has the advantage that the scale remains true even if the map is enlarged or reduced mechanically. The first method is particularly useful since any unit of measurement may be used; e.g., if one uses metric units, a scale of 1:100,000 would mean that one centimeter on the map represents one kilometer on the earth’s surface (since 100,000 centimeters equals one kilometer). The more the size of features on the map approaches the features’ actual size on the earth’s surface, the larger the scale of the map is said to be. A large-scale map usually shows more detail than does a small-scale map, but covers a smaller area than does a small-scale map of the same size.

MAP SCALES & UNITS

This handout was designed to help you understand the relationships between different map scales, map units, distance, and area. You should understand the logic behind how these are used and how they should appear on real topographic maps. On your upcoming lab exam, you should also be able to convert one type of map scale into another, and calculate size differences (scale factor, area factor) between different maps.
A. Review of Common Types of Map Scales

All map scales are an expression of the numerical relationship between the MAP and the LAND that is represented. The MAP unit is always mentioned first.

1. Verbal Scale: The verbal scale is just a sentence stating that “1 Map Unit = X Land Units”. For reasons of convenience, a mixture of units is commonly used, such as

1 inch  = 1 mile

However, there are NO requirements that the units must be different! The expression “1 inch = 63,360 inches” is still a verbal scale. A mixture of map and land units makes the verbal scale difficult to compare between different maps – it must be converted first to a Representative Fraction (see below).
2. Representative Fraction (R.F.): An R.F. scale is a ratio, or fraction, that expresses the mathematical relationship between MAP and LAND, such as

1 : 24,000

which means “1 map unit is equivalent to 24,000 land units.” Because an R.F. carries no units (inches, centimeters, etc.), it means that the R.F. scales can be compared between different maps. Converting an R.F. scale to a verbal scale is very easy; simply select ONE unit and apply it to BOTH map and land numbers. The above example can be written as a verbal scale as “1 inch = 24,000 inches” or “1 meter = 24,000 meters,” etc. (Note: YOU CANNOT MIX UNITS in an R.F.! Doing so will change the numerical relationship of the R.F.)
3. Graphic Scale: The graphic scale is a bar chart or “ruler” that is drawn at the bottom of a topographic map. This is the scale that you should use when asked to measure distances on the map. Be Careful: Note that the zero mark is not located at the left end of the graphic scale. For your convenience, the graphic scale extends to the left of the zero mark to indicate fractions of units, such as 1/10 of a mile. You may measure distances by marking off the 2 end points on the edge of a sheet of paper and aligning the edge of the paper against the graphic scale (make sure one of your marks is on the zero).

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TYPES OF MAPS

There are several types of maps. Each show different information. Most maps include a compass rose, which indicates which way is north, south, east and west. They also include a scale so you can estimate distances. Here’s a look at some different types of maps.

Climate maps

give general information about the climate and precipitation (rain and snow) of a region. Cartographers, or mapmakers, use colors to show different climate or precipitation zones.

Economic or resource maps

feature the type of natural resources or economic activity that dominates an area. Cartographers use symbols to show the locations of natural resources or economic activities. For example, oranges on a map of Florida tell you that oranges are grown there.

Physical maps

illustrate the physical features of an area, such as the mountains, rivers and lakes. The water is usually shown in blue. Colors are used to show relief—differences in land elevations. Green is typically used at lower elevations, and orange or brown indicate higher elevations.

Political maps

do not show physical features. Instead, they indicate state and national boundaries and capital and major cities. A capital city is usually marked with a star within a circle.

Road maps

show major—some minor highways—and roads, airports, railroad tracks, cities and other points of interest in an area. People use road maps to plan trips and for driving directions.

Topographic maps

include contour lines to show the shape and elevation of an area. Lines that are close together indicate steep terrain, and lines that are far apart indicate flat terrain.

Planimetric Map. A planimetric map presents only the horizontal positions for the features represented. It is distinguished from a topographic map by the omission of relief, normally represented by contour lines. Sometimes, it is called a line map.

Topographic Map. A topographic map portrays terrain features in a measurable way, as well as the horizontal positions of the features represented. The vertical positions, or relief, are normally represented by contour lines on military topographic maps. On maps showing relief, the elevations and contours are measured from a specific vertical datum plane, usually mean sea level.

Photomap. A photomap is a reproduction of an aerial photograph upon which grid lines, marginal data, place names, route numbers, important elevations, boundaries, and approximate scale and direction have been added.

Military City Map. A military city map is a topographic map (usually at 1:12,550 scale, sometimes up to 1:5,000), showing the details of a city. It delineates streets and shows street names, important buildings, and other elements of the urban landscape important to navigation and military operations in urban terrain. The scale of a military city map depends on the importance and size of the city, density of detail, and available intelligence information.

Special Maps. Special maps are for special purposes such as trafficability, communications, and assault maps. They are usually in the form of an overprint in the scales smaller than 1:100,000 but larger than 1:1,000,000. A special purpose map is one that has been designed or modified to give information not covered on a standard map. The wide range of subjects that could be covered under the heading of special purpose maps prohibits, within the scope of this manual, more than a brief mention of a few important ones. Some of the subjects covered are:

• Terrain features.
• Drainage characteristics.
• Vegetation.
• Climate.
• Coasts and landing beaches.
• Roads and bridges.
• Railroads.
• Airfields.
• Urban areas.
• Electric power.
• Fuels.
• Surface water resources.
• Ground water resources.
• Natural construction materials.
• Cross-country movements.
• Suitability for airfield construction.
• Airborne operations.

 

If military maps are not available, use substitute maps. The substitute maps can range from foreign military or commercial maps to field sketches. The NGA can provide black and white reproductions of many foreign maps and can produce its own maps based upon intelligence.

Foreign Maps. Foreign maps have been compiled by nations other than our own. When they must be used, the marginal information and grids are changed to conform to our standards, if time permits. The scales may differ from our maps, but they do express the ratio of map distance to ground distance and can be used in the same way. The legend must be used since the map symbols almost always differ from ours. Because the accuracy of foreign maps varies considerably, they are usually evaluated in regard to established accuracy standards before they are issued to our troops.

Atlases. Atlases are collections of maps of regions, countries, continents, or the world. Such maps are accurate only to a degree and can be used for general information only.

Geographic Maps. Geographic maps provide an overall idea of the mapped area in relation to climate, population, relief, vegetation, and hydrography. They also show the general location of major urban areas.

Tourist Road Maps. Tourist road maps are maps of a region in which the main means of transportation and areas of interest are shown. Some of these maps show secondary networks of roads, historic sites, museums, and beaches in detail. They may contain road and time distance between points. The scale should be carefully considered when using these maps.

City/Utility Maps. City/utility maps are maps of urban areas showing streets, water ducts, electricity and telephone lines, and sewers.

TOPOGRAPHIC MAPS

Topographic maps show a 3 dimensional world in 2 dimensions by using contour lines. Many people have trouble reading these maps, because they have mountains and valleys are represented with concentric circles and lines. Many hikers use topographic maps, especially in areas where there are no roads with signs. Geologists depend on topographic maps to record the types of rocks. Engineers use topographic maps when they are planning roads, buildings, or other human–made structures. Imagine designing a city without considering where hills and valleys are located!

GEOLOGIC MAPS

A geologic map is a map of the different types of rocks that are on the surface of the Earth. By mapping different rock types, geologists can determine the relationships between different rock formations which can then be used to find mineral resources, oil, and gravel deposits. Also, you want to know what type of rock you are building on or else you might have a Leaning Tower of Pisa or a pile of rubble after a strong earthquake.

BIOGEOGRAPHIC MAPS

Scientists involved in the study of animals, plants, and other living organisms use maps to illustrate where these groups live or migrate. It is important to many zoologists to know where the organisms that they study live and where they move to. People who monitor endangered species need to know if the ranges of migration have become larger or smaller through time.

ENVIRONMENTAL MAPS

These types of maps include maps that look at human’s activity in urban and metropolitan areas and the environment in which we all live. Maps that illustrate physiographic features such as forests, grassland, woodland, tundra, grazing land, ocean floors, and ocean sediments could be included in this large grouping.

Meteorological maps that show climate, weather and wind are types of environmental maps. Meteorologists, oceanographers, geographers, city planners, and many other professionals depend greatly on these maps to record and forecast their specific field.

 5 TYES OF MAPS:

There are basically 5 types of maps. They are climate maps, economic or resource maps, environmental maps, political maps, topographic maps.

Climate maps give information about climatic and precipitation conditions prevalent in a region. Precipitation – rain AND/OR snow.

Economic or resource maps feature the type of natural resources or economic activities known in that area.

Physical maps show the physical features of an area, such as mountains and rivers. They usually use colors such as blue, green and orange. Green is usually used for low-lying areas and orange is used for higher altitudes.

Political maps indicate state and national boundaries.

Road maps show the major highways, railway tracks, airports and places of interest within a country, county, state, province or city.

Topographic maps are maps which use contour lines to highlight the shape and elevation of an area. Closer contours mean a steeper terrain, and if the lines are far apart from each other- it indicates a flatter terrain.

such as globle warming as you know are states are moving slowley in life so the types of maps can change.

TYPES OF MAPS

Well there are quite a few types of maps and it depends on where you are and where you’re going.

Thematic Maps: show features, population, and rainfall

Inventory Maps: concentrate on a specific feature and show precise location

Political Maps: boundries of countries, provinces, and states

Mobility Maps: help people find their way on land, water, and air

Transit: routes of buses, trains, subways, public transportation.

Charts: help ships and planes

Types of Maps

There are different types of maps meant for various purposes. Most of us are only aware of the political and road maps, however, there’s more to maps than we know. Read on to know more.

We depend on maps all the time, to guide us and help us reach our destination. The GPRS system is gaining popularity and myriads of people are depending on this system to find their way around. Even in malls we depend on the map of the mall provided to find the store we want (especially the food court!).

Maps are ingenious inventions of man, without which we would have had to spend scores of hours locating places and wasting precious time by getting lost. All this time wastage can be avoided today by referring to maps and obeying the instructions with respect to the direction given on it. Maps are actually representations of the Earth’s surface that depicts where what is located on the earth and the respective distance from one place to another. It gives you a bird’s eye view of places, distances, direction and size. Moreover, what’s best is that these maps are sheets of paper that can be rolled and carried around wherever you go. There are different types of maps suited for various needs. Let’s have a look at the different types of maps and their uses.

Different Kinds of Maps and Their Uses

The different types of maps and their uses are as follows:

Climate Maps or Weather Maps
Not all maps are used to find places, locate landmarks and streets, instead there are weather maps as well that help weather forecast. They are depictions of weather patterns prevalent in particular areas. The information presented on these climate maps can be jotted down and used for various purposes. These maps actually map factors such as temperature, precipitation, seasonal variations and various geographical features that help distinguish the several climate zones (arid, equatorial, warm-temperature, snow and polar). The data on these maps keep constantly changing due to changing climatic conditions. To attain this climate information, various data fields such as satellite images, radar, etc. are used, which are then combined to form one picture that can be printed out or viewed digitally. Read more on how to read a weather map.

Physical Maps
These maps are special maps depicting physical characteristics of a place, for example, it denotes the various landforms like mountain ranges, valleys, deserts, plains, etc. and water bodies like rivers, lakes, seas, oceans, etc. The elevations of mountain ranges are shown by the various lines, shading patterns, spots, tints, etc. in different colors on the maps. Blue color is used to depict the water.

Political maps
Political maps are maps we are all familiar with. These maps represent the different nations across the globe along with the state divisions, their capitals and important cities. Thanks to these maps we can learn more about nations and their cities.

Economic or Resource Maps
These are the maps that are used to represent the economic resources or natural resource wealth of a particular region across the globe. Symbols are used on the map to denote a particular resource. For example, the presence of oranges on the map tells us that Florida is rich in oranges, whereas, the presence of wheat on the map quickly tells us that wheat is grown in abundance in Maryland. Other resources like coal, petroleum, oil, metals, etc. also have their respective symbols that tell us where they are found in abundance. Thus, at one glance, one can find out the resources of different places.

Road maps
This is another type of map we are all familiar with. Going for a holiday by road and not taking a map is like going to the Alps in your summer clothes. In fact road maps also help us find places in our own city. Road maps represent street directions to places across the city. This road to road direction helps us find our way really easily.

Topographic maps
Some of us have had the privilege of learning how to read these maps at school itself. These maps feature contour lines that denote shape and elevation of a particular region. This means if the region houses steep terrain, the lines will be close to each other, while flat terrain is denoted by lines separated by a larger distance. These maps are very important for construction and road work. Moreover, even geologists use the help of these maps to collect data and record types of rocks.

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CONVENTIONAL SIGNS

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. These signs are usually explained in the margin of the map, or on a separately published characteristic sheet

A map is a birds eye view of a piece of land draw on a mangerbal piece of paper only accret to the day it was printed., almost everything that appears on a map, except a written name, is a conventional sign.

Conventional signs are designed to enable the maximum amount of information to be put on a map in the clearest way possible.

Why are symbols used in maps?
Because there’s not enough room to print the words of the items represented by the symbols.

For simplicity and due to space constraints. It makes the map easier to understand. In addition, if full names of features were to be used on maps, it would be too messy to read.

Since a map is a reduced representation of the real world, map symbols are used to represent real objects. Without symbols, we wouldn’t have maps.

Both shapes and colors can be used for symbols on maps. A small circle may mean a point of interest, with a brown circle meaning recreation, red circle meaning services, and green circle meaning rest stop. Colors may cover larger areas of a map, such as green representing forested land and blue representing waterways.

To ensure that a person can correctly read a map, a Map Legend is a key to all the symbols used on a map. It is like a dictionary so you can understand the meaning of what the map represents.

LIST OF CONVENTIONAL SIGNS (CLICK THE BELOW GIVEN LINK)

CONVENTIONAL SIGNS

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MAP READING

Map Reading Basics

By Matt Rosenberg

Maps are the basic tools of geography. They enable us to depict spatial phenomenon on paper. There are conventions used in cartography which allow a map to be read efficiently and quickly.

A good map will have a legend or key which will show the user what different symbols mean. For instance, a square with a flag on top usually represents a school and roads are represented by a variety of widths and combinations of lines. Often a dashed line represents a border. Note, however, that map symbols used in the United States are often used for different things in other countries. The symbol for a secondary highway on a USGS Topographic map is equivalent to a railroad in Switzerland. Make sure to read the legend and you’ll understand the symbols.

Every map is a representation of a larger portion of the earth. Read the feature about scale to learn more about how to determine the distance on earth represented on the map.

Without a north arrow, it is difficult to determine the orientation of a map. With a north arrow (pointing in the correct direction), a user can determine direction. Some maps, such as topographic maps, will point to “true north” (the north pole) and to magnetic north (where your compass points, to northern Canada). Usually, you won’t see something quite as detailed as a compass rose but a map does need to provide orientation.

A neatline is the border of a map. It helps to define the edge of the map area and obviously keeps things looking “neat.”

Since the map is a flat representation of the curved surface of the earth, all maps are inherently inaccurate. There are a variety of projections which have been formulated for different uses.

A map’s title provides important clues about the cartographer’s intentions and goals. You can hope to expect entirely different information on a map titled “Unemployment in Jefferson County” versus “Topography of Mount St. Helens.”

Color appears so often on maps that we often take it for granted that mountains are brown and rivers are blue. Just as there are many types of color maps, there are also many different color schemes used by cartographers. The map user should look to the legend for an explanation of colors on a map.

Our expectations of colors on a map leads to some problems when it is used for elevation. Elevation is often represented as a sequence of dark greens (low elevation or even below sea level) to browns (hills) to white or gray (highest elevation). Since many people associate green with a fertile region, many map users will see lower elevations, which may be deserts, and assume those areas are filled with lush vegetation. Also, people may see the reds and browns of mountains and assume that they are barren, Grand Canyon-type landscapes of desolation but the mountains may be forested and covered in brush.

Additionally, as water always appears bright blue on a map, the user is often inclined to visualize any water on a map as pristine and clear blue – even though it might be entirely different color due to pollution.

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MAP – MEANING

  MAP

A map is a flat, two-dimensional representation of an area. Usually maps present a view from above. Normally the space they represent is a geographic area (cities, towns, countries or neighbourhoods, for example), but maps can in theory represent non-geographical things (a “map” of the circulatory system) or even things with no physical reality at all (a “map” of someone’s consciousness).

A globe is a three-dimensional map of the earth overlayed on a sphere. Other differences include the fact that any large map, being an attempt to display part of the surface of a sphere (the earth) on a flat sheet of paper, is always distorted to some degree, while a globe is not.

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