06. map work

MWL. RAHIM RASHID CHANZI …. Facebook follow us on “geography for secondary school-o level” 0713-391363
mwl rahim rashid chanzi
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MAP WORK
Map is the representation of the part or the whole part of the earth’s surface on the flat surface. E.g.
sheet of paper or wood.
The science of designing and making map is known as cartography while cartographer is the person
who designs and make a map
Essential or components or supportive content of a map
1. Tittle
It is used to tell what the map about.
2. A key
These are symbols and sign which describe the represented features.
3. A margin
It shows the limitation of the map in the mapped area.
4. A scale
It shows the ration between map distance and ground distance.
5. North direction
It shows the direction toward the north in the mapped area.
6. Date of compilation
It shows when map was constructed, hence depicts weather map is outdated or updated.
IMPORTANCE OF MAP
(a) Map help to locate position
(b) It is used in military activities
(c) Map provide distribution of information. E.g. mountains.
(d) It is used for travelers and pilots.
(e) It is used by land planner and surveyors.
(f) Map is used to store geographical information
(g) It is used to determine distance between places
TYPES OF MAP
There are three types of maps namely:
1. Topographical map 2. Statistical map 3. Thematic map
(a) Topographical map
These are the maps which shows man- made and natural features
(b) Statistical map
These are maps which describe the distribution of natural features.

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(c) Thematic map
This is the chart especially designed to show a particular theme connected with specific
geographical area. E.g. climate, population density or health issues
Examples of physical (natural) features Lakes, oceans, mountains, plains, valleys, ponds, hills,
plains etc.
Examples of artificial (man-made) features are Farms, roads, factories, building, houses, and dams
MAP SCALE
Map scale is the ratio or relationship between map distance and actual distance.
Ways of Expressing map scale.
Map scale can be expressed in three ways, namely.
1. Statement scale
2. Representative fractional scale or ratio {RF}
3. Linear scale
Statement scale
Statement scale is the scale which is stated in word or verbal means
E.g. one centimeter represents half kilometer.
Properties of statement scale
1. The scale is expressed as word statement
2. The scale bare specific unit of measurement
3. The word “represent” should be used and not equal or equivalent
4. Map distance is expressed as 1.
Representative fractional scale or ratio
This is the scale which expressed in ration. E.g. 1: 50, 000
Properties of RF scale
1. The scale doesn’t show unit of measurement
2. The top number (numerator) represent the map distance and always reduced to 1
3. The bottom number (denominator) represent the ground distance is more than 1
4. Linear scale
This is the scale which is presented in form of graphic or line.

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Properties of linear scale
1. This scale is expressed in graphic form
2. They show specific unit of measurement
3. It is not affected by map reduction or enlargement
TYPES OF SCALE
There are three types of map scale, namely
1. Small scale
2. Medium scale
3. Large scale
Small map scale
Maps drawn on small scale are called small scale map. This map represents large area of land on
small size of paper. E.g. map of 1:500,000
Characteristics of small scale.
1. It has the largest denominator.
2. It represents large area
3. Contains a lot of geographical information.
4. It shows less details.
Medium map scale
These are scale ranging between small and large. It is used when map cover medium area. E.g.
1:250,000, 1:50 000
Large map scale
Maps drawn in large scale are called large scale map. It covers small area on the earth surface.
E.g.1:25,000.
Characteristics of large scale.
1. It has smaller numbers in the denominator.
2. It shows features clearly
3. It contains geographical details.
CONVERSION OF SCALE
Scale can be converted from one form to another.
1. Statement scale into representative fractional scale (RF)
Example: one centimeter represents half kilometer. Change into RF.
Solution
𝑟𝑒𝑐𝑎𝑙𝑙 1𝑘𝑚 = 100,000𝑐𝑚

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1𝑘𝑚 = 100,000𝑐𝑚
1
2
𝑘𝑚 = 𝑥
0.5𝑘𝑚 𝑥 100,000𝑐𝑚
1𝑘𝑚
= 𝑥
50,000cm = x
RF 1:50,000
2. RF scale into statement scale
Example: 1:50,000 change into statement scale
Solution
1𝑘𝑚 = 100,000𝑐𝑚
𝑥 = 50,000𝑐𝑚
1𝑘𝑚 𝑥 50,000𝑐𝑚
100,000𝑐𝑚
= 𝑥
1
2
𝑘𝑚 = 𝑥
∴One centimeter represents half kilometer
3. Linear scale into statement scale
Example: change linear scale below into statement scale.
Solution
1. Measure the length of linear scale from the 0 mark toward the right up to number 1.
2. From the given scale one interval represent one (1) kilometer while the interval has
two (2) centimeter – 2cm
Hence 2cm represent 1 kilometer.

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Since map distance always carries 1 digit.
2𝑐𝑚
2
=
1𝑘𝑚
2
1cm =
1
2
𝑘𝑚
statement scale: one centimeter represents half kilometer.
USES OF THE MAP SCALE
1. Scale is used to estimate distance
2. Scale is used to measure areas
3. Scale is used to calculate areas
4. scale is used to calculate gradient
5. Scale is used in drawing a map
MEASURING OF DISTANCE ON MAP
Distance on the map can be measured by using the following methods
1. By using a pair divider method
2. By using a string or thread method
3. By using a piece of paper method
Pair divider method
Pair divider involve marking of short distance, measuring the distance and make summation.
String or thread method
String or thread method involve measuring the line from one point to another by thread on the
linear scale.
Piece of paper method
Piece of paper method involve measuring the short distance by the edge of the piece of paper.
Then the total length marked on the edge of paper is read from the linear scale.
Example: measure the distance of all-weather road from grid references 680015 to kasulu town 774955 in
km.
Data given
scale = 1:50,000
Map distance 25cm
Ground distance km?
Solution
From the scale 1:50,000

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1𝑘𝑚 = 100,000𝑐𝑚
𝑥 = 50,000𝑐𝑚
1𝑘𝑚 𝑥 50,000𝑐𝑚
100,000𝑐𝑚
1
2
𝑘𝑚
1cm =
1
2
𝑘𝑚
1𝑐𝑚 =
1
2
𝑘𝑚
25cm = x
25𝑐𝑚 𝑥 0.5 𝑘𝑚
1𝑐𝑚
= 𝑥
X= 12.5 km
The distance of all-weather road is 12.4km.
MEASUREMENT OF ARES ON A MAP
The area which is measured on a map can be categorized into two types.
1. Regular shapes
2. Irregular shapes
REGULAR SHAPES
Features on the map which is appear in regular shapes are triangles, rectangles, square and circle. Area
of these shape is calculated by applying mathematical formula.
(a) To measure are of square.
Measuring area of square involve finding the product of length.
Are 𝑙𝑒𝑛𝑔𝑡ℎ 𝑥 𝑙𝑒𝑛𝑔𝑡ℎ = 𝑙2
4m x 4m = 16m2
16m2
will be converted with the scale given to get distance from the ground.
4m
4m

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(b) To measure the area of rectangle
Measuring the area of rectangle involve finding the product of length and width.
Are 𝑙𝑒𝑛𝑔𝑡ℎ 𝑥 𝑤𝑖𝑑𝑡ℎ
7m x 5m = 35m2
35m2
will be converted with the scale given to get distance from the ground.
(c) To measure the area of a triangle
1
2
𝑏𝑎𝑠𝑒 𝑥 ℎ𝑒𝑖𝑔ℎ𝑡
1
2
𝑥 4𝑚 𝑥5𝑚 = 10𝑚2
10m2
will be converted with the scale given to get distance from the ground
(d) To measure the area of a circle
The area of a circle is calculated by formulae 𝜋𝑟2
Area 22
7⁄ 𝑥 7 𝑥7 = 154 𝑚2
154m2
will be converted with the scale given to get distance from the ground
5m
7m
5m
4m
7m

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IRREGULAR SHAPE.
These methods are used to calculate the area which cannot be calculated by using simple mathematics
formulae. These areas include shapes of lakes, islands, forests, plantations, settlements etc.
Method of calculating irregular shape.
1. Tracing or grid reference method
2. Striping method
3. Division method
(a) Tracing method (grid reference)
Tracing method involves counting number of Full Squares and half squares. Total square is
obtained by adding up Full Squares and half squares which is divided by two.
Example find the area of cocoa plantation in km2
Hence
Full Square: 28
Half square 26
Scale. 1:50,000
Total squares = full square +
ℎ𝑎𝑙𝑓 𝑠𝑞𝑢𝑎𝑟𝑒
2
28+26/2
28+13
41 squares.
Area of one square 1cm x 1cm = 1cm2
1𝑠𝑞𝑢𝑎𝑟𝑒 = 1𝑐𝑚2
41 𝑠𝑞𝑢𝑎𝑟𝑒 𝑥
41 𝑠𝑞𝑢𝑎𝑟𝑒 𝑥 1𝑐𝑚2
1 𝑠𝑞𝑢𝑎𝑟𝑒
= 𝑥
X = 41 cm2
From the scale 1:50,000
Scale: 1:50,000

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1𝑘𝑚 = 100,000𝑐𝑚
𝑥 = 50,000𝑐𝑚
1𝑘𝑚 𝑥 50,000𝑐𝑚
100,000𝑐𝑚
= 𝑥
1
2
𝑘𝑚 =x
1cm =
1
2
𝑘𝑚
(1cm) 2
= (
1
2
𝑘𝑚) 2
1cm2
= 0.25km2
1cm2
= 0.25km2
41cm2
= x
41𝑐𝑚2
𝑥 0.25 𝑘𝑚2
1𝑐𝑚2
= 𝑎𝑟𝑒𝑎
Area = 10.25 km2
The area is 10.25km2
(b) Stripping method
The stripping method involves dividing the area into strips and then calculating the area of each
strip separately. The total area is obtained by summing up the areas of all rectangular strips.
Divide the area into uniform rectangular strips.
Calculate the area of each rectangular strip separately. Remember that the areas of the strips.
Add up the area of each strip to get the total area.
Area = sum of the areas of all individual strips = area of strip 1 + 2 + 3 + 4 + 5

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(c) Division methods
Division method involves tracing the required shape and subdividing dividing the traced shape into
smaller rectangles, square, or triangles. Then the areas are calculated separately and then added
to find its summation
The area above is divided into three figures A, B and C. The area of the three resulting figures is
calculated as follows:
Rectangle A: Area = L x W = 10 x 5 = 50 cm2
Triangle B: Area = ½bh = ½x 6 x 4 = 12 cm2
Triangle C: Area = ½bh = ½x 4 x 3 = 6 cm2
Total area = A + B+ C = 50 km2
+ 12km2
+ 6km = 68 cm2
(convert with scale provided)
LOCATING POSITION ON THE MAP
The major method which used to show the position of a place includes.
(a) Place naming. E.g. kibondo.
(b) Compass bearing
(c) Grid reference
(d) Latitude
(e) longitude
Place naming.
Name of a place on a map may be used to locate position on an area or place. Example Arusha,
Mbeya, kondoa, kibondo etc.
Compass bearing
Compass bearing can be measured by a compass. A compass is an instrument which used to
locate and find direction. Compass has four direction namely, East, North, South and West.
Bearing is the angle measured in degree clockwise from the line of magnetic north to the line of
sight.
Types of bearing
1. Backward bearing
It is found from 0000
to 1800
2. Forward bearing
It is found from 1810
to 3600

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HOW TO MEASURE BEARING
Procedure.
 Establish two point on the map (A and B)
 Join the point A and B by straight line.
 On point of reference (to or from) draw vertical line of north direction
 Draw the clockwise line from vertical line
 Measure the angle carefully using protectors
 Read and record the angle size in three digit 0000
Example measure the bearing of point A from B.
Example measure the bearing of point A to B.
GRID REFERENCE
A grid system is the pattern of horizontal and vertical lines forming square of uniform size drawn on a
map.
Grid system is numbered East and North. Hence referred as Easting and Northing. Both easting and
northing have three digits. Hence grid system has six (6) digits.

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Reading of grid system start from easting then northing.
Hence the grid reference of A is 380430.
DIRECTION
Direction is a line along which something is moving, pointing or facing.
Compass direction
Compass direction is the direction which is determined by instrument known as compass
Types of compass direction
1. Normal compass direction
2. Four compass direction
3. Eight compass direction
4. Sixteen compass direction
Normal compass direction
This is the compass that shows only two major direction on the globe.
Four compass direction
This is the compass which shows the four major direction of the globe. This consist of North,
South, East and West
A
N
S

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Eight compass direction
Four compass direction can be divided into eight cardinal points. Eight cardinal points are shown
on below diagram.
Sixteen compass direction
The eight-compass direction can be divided into sixteen cardinal point. As shown on the diagram
below.

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THE NORTH.
There are three kinds of North indications on a map. This include
1. Magnetic north
2. True north
3. Grid north
(a) Magnetic north is the direction which is shown by magnetic compass which always points the
magnetic north pole.
(b) Grid north is the direction toward the north in the map drawn to grid reference.
(c) True north is the direction toward 900
north latitudes from any place on the earth’s surface.

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SYMBOLS AND SIGNS
Information on a map is given in symbol and signs which are the alphabet of map. It is aided by the key.
The difference between the two symbol and sign is that sign is a language on its own and it is used to
communicate something to people while symbol is subjective in nature and often requires interpretation.
USES OF MAP
1. It used to store geographical information
2. It used in studying geography
3. It shows geographical features
4. It shows the climate of the place
5. It used for travelers
6. It used to give location and position of a place
7. It shows used to show distribution of feature.

06. map work

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06. map work