Representation Of Geographical Features on Topographical Sheets
1. Fill in the blanks:
a) Topographical maps are prepared on the basis of a detailed survey of the areas concerned.
b) Map scale refers to the ratio of the distance on the map and the corresponding actual distance on the ground.
c) Contour lines depicts the physical features of a place.
d) the colour green is used to represent the different kinds of vegetation.
e) Latitudes and longitudes on the topographical map indicate the exact location of a place.
2. Match the following:
3. State whether the following statements are 'true' or 'false':
a) A map represents the spherical Earth on a flat paper.[T]
b) Scale written in a statement form like 2 cm to a km is called representative fraction.[F]
c) When we need to measure distance along a curved line, we first mark the two points whose distance is to be measured.[T]
d) Maps use signs and symbols that are not accepted internationally to depict certain features and characteristics.[F]
e) Drainage features include all natural and human-made water features.[T]
4. Draw the symbols of the following:
5. Answer the following questions:
a) What features do yellow, brown and red represent on topographical maps?
= The yellow feature represents arable or agricultural land.
The brown feature represents contour heights; sand features such as sand dunes.
The red feature represents permanent settlements; grid lines; cart track and metaled road.
b) Explain the different types of scales.
= There are different types of scales such as verbal statements, representative fraction and linear scale. Let us know more about these scales in detail.
Verbal statement: Scale written in a statement from like 2 cm to 1 kilometre is called verbal statement. It means that 2 cm on the map represents one kilometre on the earth.
Representative Fraction: Scale can also be written as a representative fraction(R.F.). For example 1:50,000; it means 1 cm on the map represents 50000 or half kilometre on the ground. It shows the ratio between map distance and ground distance.
Linear Scale: Scale can be drawn on a line to show map distance equivalent to ground distance. A line is divided into equal parts. Each part represents the actual distance on the ground in m/km.
c) How is distance measured along a straight line on the map using scales?
= We first measure it with the divider. Thereafter, the divider is placed on the ruler to get the exact map distance in centimetres. Based on the scale given for the map it will be easy to calculate the ground distance between two given points in metres and kilometres.
For example, the scale of the given map is 1:100,000 that is one centimetre to a km.
If one cm represents 1 kilometre on the map, therefore 6.4 centimetre represent 6400 or 6.4 kilometre, therefore map distance 6.4 cm is equal to actual distance of 6.4 kilometre on the ground.
d) What are conventional symbols?
= Maps use a set of standard signs and symbols that are internationally accepted to depict certain features and characteristics these are known as conventional symbols. With the help of the symbols, it becomes very easy to read and understand a map.
e) How are boundaries shown on topographical maps?
= Administrative boundaries are shown in black with various symbols made up with lines; dots and dashes. Boundaries may be international, national, state, district and tehsil or taluk.