MAP SCALE
Before making a map of the Earth or any part of it, we decide how much distance of the surface is to be shown from the distance of the map. Thus we establish a relation between the distance of the map and the distance to the surface. This relation gives rise to the scale. The scale is the ratio in which distances measured on the ground are truncated and displayed in the map. In simple terms, "a straight distance between any two points on a map or a ratio of the actual straight distance between those two points on the earth is called a scale." Scale is the ratio between a distance mea sured on a map and the corresponding distance on the Earth. This can also be expressed in the following formula
distance between two points on the map
Scale = ---------------------------------------------------------
We can make a plane measurement when the statement or demonstrator is given separately. When creating a linear scale the following things must be kept in mind:
distance between same two points on the ground
For example, suppose A and B are two points on a map, the distance between which is 1 cm and the distance between these two points on the ground is 5 kilometers, then the scale of that map would be 1 cm: 5 km.
Necessity of Scale
(1) The size of the map is much smaller than the area to be displayed, indicating its usefulness and significance. Map should be sized as required. This work can be done only by the scale.
(2) In the absence of a gauge, the relative position of different places on the map i.e. distances cannot be shown . The map which is drawn according to the scale - is only a rough sketch.
For example, suppose A and B are two points on a map, the distance between which is 1 cm and the distance between these two points on the ground is 5 kilometers, then the scale of that map would be 1 cm: 5 km.
Necessity of Scale
(1) The size of the map is much smaller than the area to be displayed, indicating its usefulness and significance. Map should be sized as required. This work can be done only by the scale.
(2) In the absence of a gauge, the relative position of different places on the map i.e. distances cannot be shown . The map which is drawn according to the scale - is only a rough sketch.
Methods of Expressing Scale on a Map
By measuring the scale on the map by the following three methods can be displayed
(1) Statement of Scale
(2) Representative Fraction
(3) Linear Scale
1. Statement of Scale - In this method, its scale is written in words on a map; Like 1 centimeter: 2 kilometers. This means that a distance of 1 cm on the map is showing a distance of 2 kilometers of the ground. The number on the left-hand side in the narrative scale always shows the distance on the map. Other names for this method are also descriptive measure and literal interpretation method.
2. Representative Fraction - In the method, the scale is represented by a fraction. Its numerator always represents one. (1) of this fraction which is the distance on the map Like 1,00,000 Denominator denotes distance on the ground. Map The fraction remains the same after changing the scale .
Distance on the map
Representative Fraction (R.F.) = ----------------------------------------
Distance on the ground
The important thing about this method is that the numerator and each are expressed in the same unit. In the above example, the scale of the map is 1: 1,00,000 or 1 / 1,00,000, so this means that 1 unit of distance on the map represents the same distance of 1,00,000 on the ground. If this unit is 1 cm on the map, it will show a distance of 1,00,000 cm on the surface.
3. Linear Scale - In this method the distance of the map is represented by a simple line which is proportional to the distance to the surface. According to convenience, this line is divided into Primary and Secondary parts. Before constructing a linear scale, we need to find ways to divide a simple line into equal parts because without it a pure linear scale cannot be composed. There are two methods.
First method: Suppose AB is a given straight line that has to be divided into 6 equal parts.
(1) Draw a line AC forming the acute angle at the A end.
(2) Now fill any distance in the circle and mark six points D, E, F, G, H and I at equal spacing in the AC line.
By measuring the scale on the map by the following three methods can be displayed
(1) Statement of Scale
(2) Representative Fraction
(3) Linear Scale
1. Statement of Scale - In this method, its scale is written in words on a map; Like 1 centimeter: 2 kilometers. This means that a distance of 1 cm on the map is showing a distance of 2 kilometers of the ground. The number on the left-hand side in the narrative scale always shows the distance on the map. Other names for this method are also descriptive measure and literal interpretation method.
2. Representative Fraction - In the method, the scale is represented by a fraction. Its numerator always represents one. (1) of this fraction which is the distance on the map Like 1,00,000 Denominator denotes distance on the ground. Map The fraction remains the same after changing the scale .
Distance on the map
Representative Fraction (R.F.) = ----------------------------------------
Distance on the ground
The important thing about this method is that the numerator and each are expressed in the same unit. In the above example, the scale of the map is 1: 1,00,000 or 1 / 1,00,000, so this means that 1 unit of distance on the map represents the same distance of 1,00,000 on the ground. If this unit is 1 cm on the map, it will show a distance of 1,00,000 cm on the surface.
3. Linear Scale - In this method the distance of the map is represented by a simple line which is proportional to the distance to the surface. According to convenience, this line is divided into Primary and Secondary parts. Before constructing a linear scale, we need to find ways to divide a simple line into equal parts because without it a pure linear scale cannot be composed. There are two methods.
First method: Suppose AB is a given straight line that has to be divided into 6 equal parts.
(1) Draw a line AC forming the acute angle at the A end.
(2) Now fill any distance in the circle and mark six points D, E, F, G, H and I at equal spacing in the AC line.
(3) Match the point IB with a straight line.
(4) Now draw lines parallel to IB line from points D, E, F, G and H.
In this way the AB line will be divided into 6 equal parts.
Second method: Suppose AB is a given line which has to be divided into five equal parts.
(1) Opposite at both ends of the line A and B Draw two equal acute angles (can also take vertical angles) in directions.
(2) Now fill any distance in the circuit, five from Vidu A. Mark the points C, D, E, F and G.
(3) Similarly, at the same distance from point B, mark five points C, D, E, F 'and G'.
(4) Now mix A to G ', C to F, D to E', E to D ', F to C' and G to B. In this way five equal parts of the AB line will be formed.
Drawing of Linear Scale
(4) Now draw lines parallel to IB line from points D, E, F, G and H.
In this way the AB line will be divided into 6 equal parts.
Second method: Suppose AB is a given line which has to be divided into five equal parts.
(1) Opposite at both ends of the line A and B Draw two equal acute angles (can also take vertical angles) in directions.
(2) Now fill any distance in the circuit, five from Vidu A. Mark the points C, D, E, F and G.
(3) Similarly, at the same distance from point B, mark five points C, D, E, F 'and G'.
(4) Now mix A to G ', C to F, D to E', E to D ', F to C' and G to B. In this way five equal parts of the AB line will be formed.
Drawing of Linear Scale
We can make a plane measurement when the statement or demonstrator is given separately. When creating a linear scale the following things must be kept in mind:
1. The length of the scale to be measured is between 12 to 20 cm or 5 to 8 inches. By the way, according to the size of the map, a small or large scale of any length can be made.
(2) Surface distance displayed by the measure is always integer
Must be in number. An integer is a number that
2, 5, 10, 15, 20, 50, 100 or any other number
Completely divided and there is no Remainder left in it.
(3) The measure is first divided into primary divisions as per convenience. Remember, each main part also represents the whole number.
(4) Then the first main part of the left side is conveniently divided into secondary divisions. They measure small distances on the map.
(5) Zero is always inscribed except for the first major part of left side.
(6) From this zero, the unit shown by the right side main parts and the left side (left side) unit is shown by the secondary part.
(7) However, maps and atlases made by world-renowned companies use only one of the three methods of measurement. Because students are currently in the learning curve, they should write a linear scale or R.E or both with a linear scale.
(4) Then the first main part of the left side is conveniently divided into secondary divisions. They measure small distances on the map.
(5) Zero is always inscribed except for the first major part of left side.
(6) From this zero, the unit shown by the right side main parts and the left side (left side) unit is shown by the secondary part.
(7) However, maps and atlases made by world-renowned companies use only one of the three methods of measurement. Because students are currently in the learning curve, they should write a linear scale or R.E or both with a linear scale.
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