Maps and Map
Reading
Map is two-dimensional representation of the threedimensional world we are in. All maps will have the same
basic features in common and map reading is all about
learning to understand their particular “language”.
Map-is any geographic image or physical
representation of the environment, drawn to scale,
usually on a flat surface.
The term chart is most often applied to maps of the
sea, or at least, to maps used by sailors and fliers. In a
broader term, map refers more particularly to a
representation of land. The science of making maps is
called cartography.
The word map comes from the Latin word mappa
meaning “napkin” or “cloth” and the word chart comes
from the Greek chartos which means “leaf” or “sheet of
paper”.
Kinds of Maps
1. Terrain representation maps
Maps of this kind includes hachure, contour, layer tint, and
shaded relief maps.
a) Physiographic diagrams or landform maps – present
oblique views of mountains, hills and other elevated
features.
b) Block diagrams – are three dimensional perspective
representation of the earth’s crust showing the
surface of the earth and cross- sections of the
subsurface formations.
c) Relief or Physical maps – show natural feature such
as mountains, ocean, rivers and islands.
Terrain Representation Map
2. Topographic maps
A topographic map is a type of map
characterized by large-scale detail and
quantitative representation of relief, usually using
contour lines in modern mapping, but historically
using a variety of methods. Traditional definitions
require a topographic map to show both natural
and man-made features.
A topographic map uses markings such as
contour lines to simulate the three-dimensional
topography of the land on a two-dimensional
map.
Topographic Map
3. Cadastral maps
Show land boundaries and
subdivisions and are used primarily
to describe property and to define
ownership. Commonly includes
details of the ownership, the tenure,
the precise location (some include
GPS coordinates), the dimensions
(and area), the cultivations if rural,
and the value of individual parcels of
land.
Cadastral Map
4. General Atlas maps
Individual states, countries and regions are usually covered by
atlas maps. They include such information as elevation and
terrain, roads and railroads, locations of cities and towns
regional drainage patterns, selected spot elevations and
locations of historical or archeological interest.
5. Political maps
Includes political boundaries, political affiliations, place – names
such as capital cities and other important towns and selected
physical features.
A political map is a map that shows lines defining countries states
or territories. It is unlike other maps in that its purpose is to show
borders. A political map also makes a deliberate political
statement about which areas of the earth belong to a country or
state.
Atlas Map
5. Political maps
Includes political boundaries, political affiliations,
place – names such as capital cities and other
important towns and selected physical features.
A political map is a map that shows lines defining
countries states or territories. It is unlike other
maps in that its purpose is to show borders. A
political map also makes a deliberate political
statement about which areas of the earth belong to
a country or state.
Political Map
6. Thematic maps
Maps of this type normally illustrate one particular subject and may
be quantitative or qualitative.
a) Quantitative thematic maps – illustrate statistical data and
can be presented using :
1. Isorithmns – which are having lines connecting points of equal
value (ex. map of equal average precipitation)
2. Graduated circle maps – where sizes indicate totals
(ex. petroleum production)
3. Cloropleth maps – where shading or coloring indicates value
or amounts
4. Dot maps – showing distribution by dots with assigned values
5. Superimposed diagrams
b) Qualitative thematic maps – illustrate distribution on which no
percentage, ratios or other absolute quantities are involved.
Simply show the distribution of a particular quality such as
climate, soils, as vegetation.
QUANTITATIVE THEMATIC MAP
QUALITATIVE THEMATIC MAP
7. Flow maps
Direction of movement is
shown on maps of this
type. Some such maps
have set line widths or
lengths to indicate fixed
amounts and some have
a line width that varies
with the amount being
shown. Transportation
maps showing shipping
routes or air routes are
examples of flow maps.
8. Aeronautical charts
These are designed specifically for
air navigation. The charts show
features important for flying by
visual flight rules (VFR) or the
instrument flight rules (EFR)
a) Visual navigation charts –
identify those topographic
features
and contour lines that are
significant to pilots and
navigators.
b) Instrument charts – show
the control system of the
National
Airspace System and
maybe either radio navigation
charts or
instrument approach
procedure charts.
c) Nautical chart – provide
navigational aids for shipping
9. Geologic maps
Maps of this type show the distribution of rocks and other deposits
that occur at the surface of the earth as though the soil were
stripped away. These maps indicate fault lines, age of rocks, and
location of fossil samples and other features of geologic interest.
10. Road map and city maps
These are perhaps the most widely used maps.
a) Road maps show the location of roads in an area and the
distance between places, with additional information included.
b) City maps are generally at a larger scale and show greater
detail than road maps.
ROAD AND CITY MAP
How to read maps
Various kinds of information are printed on
maps to help the reader, including the map’s
title, scale, latitude and longitude, grid, and
symbols used to indicate relief and other data
and the legend that explains the symbols.
Map reading begins by noting the title.
This may be the name of the most important
place on the map. It may be the name of the
region covered by the map, or the description of
the content of the map.
Some maps and globe terms
1. Scale. It is the ratio of the distances and areas shown on the
map the corresponding distances and areas on the earth’s
surface. Scale is commonly expressed in three ways by a
statement such as on inch to a mile, meaning that one inch
on the map represents one mile on earth. By a representative
fraction (RF) such as 1:1,000,000. This means that one unit
of distance on the map represents 1,000,000 units of
distance on the earth.
Ex: One inch on the map represents 1,000,000 inches or
nearly 16 miles on the earth, and one centimeters
represents 1, 000, 000 centimeters or 10 kilometers.
By a graphic scale such as !0____!miles_____!10 The
advantage of this scale is that it remains true even if the
map is photographically enlarged or reduced.
2. Grid. The crisscross reference lines on a map. The grid
provides a frame of reference for locating points on the map.
3. Hemisphere. Half of a round objects. The equator divides the
earth into northern and southern hemispheres. The prime
meridian and the 180th meridian divide it into eastern and
western hemisphere.
4. Latitude. The distance in degrees north or south of the
equator (0latitude).
Parallel latitude - is an imaginary line circling the earth and
connecting
points on the earth’s surface having the same latitude. Parallel of
latitudes never meet. They are numbered from 00 to 900 north
and
south of the equator.
High latitudes – are latitudes between 600 and the pole in the
Northern and Southern hemispheres.
Low latitudes – are latitudes extending north and south of the
equator to 300 latitude.
Middle latitude – are latitudes between the high and low latitudes.
5. Longitude. The distance in degrees east or west of prime
meridian (0 latitude). The line connecting the north and south
pole is called meridian. A meridian is half of a great circle. For
historical reasons, the meridian that runs through Greenwich,
England, is assigned latitude of 00. It is called the Greenwich
Meridian or Prime Meridian.
6. International Date Line. An imaginary line at roughly 1800
longitude where a calendar day begins and ends. Roughly along
180° longitude, (opposite Greenwich at meridian), it corresponds
to the time zone boundary separating −12 and +12 hours.
(Note: the IDL is drawn with diversions to pass around some
territories and island groups.)
7. Distance. Straight line measurements can be taken from a
map most accurately with a pair of dividers. Any of the scale
representations may be used to determine distance.
8. Direction. The tops of most maps head north but not always.
Indicators of direction are:
a) Simple arrow pointing north
b) Two arrows, starting from the same point that shows the
difference between true north and magnetic north. There are
two kinds:
1. double barbed arrow (star stripped)- points to true north
2. single barbed arrow – denotes magnetic north.
c) Spear shaft topped by a “y”. is the grid north, where the
direction of the vertical lines in a rectangular grid that are not
meridians, therefore not true north.
9. Symbols and convention. A symbol or a conventional sign is
used to represent any feature on a map that cannot be shown
clearly and to scale. These symbols become words with definite
meaning for the map reader. Though many symbols such as
those for railroads, highways, churches and schools are
familiar, these
are usually a key to their meaning.
10. Legend. Legends or keys provide explanation for the various
symbols used. Any symbol used on a map that is not self –
explanatory should be explained in the legend.
11. Relief (or Physical map). Shows natural features such as
mountains, oceans, rivers and islands. This allows easy
recognition of individual landforms.
12. Contour lines. Are lines drawn on a map to join all points in
the same height above sea level. Contour lines are lines drawn
on a map connecting points of equal elevation. If you walk
along a contour line you neither gain or lose elevation.
13. North pole. The point farthest north on the earth’s surface(900).
Lying diametrically opposite the South Pole, it defines geodetic
latitude 90° North, as well as the direction of True North. At the
North Pole all directions point south; all lines of longitude
converge there, so its longitude can be defined as any degree
value.
14. South pole. The point farthest south on the earth’s surface
(900). Situated on the continent of Antarctica, it is the site of
the United States Amundsen-Scott South Pole Station, which
was established in 1956 and has been permanently staffed
since that year.
15. Degree. A circle can be divided into 360 degrees. A degree is
represented by a symbol ( 0 ), is divided into 60 minutes,
represented by the symbol ( ‘ ). Latitude and longitude are
shown in degrees.
16. Co-ordinates. A set of two numbers ( usually latitude and
longitude ) used in specifying the location of a point.
17. Compass rose. A symbol used show direction on a map.
This is a figure on a map or nautical chart used to display the
orientation of the cardinal directions, — north, south, east,
and west. It is also the term for the graduated markings found
on the traditional magnetic compass.