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Topo sheets are prepared three mainly in groups in India :

1. The million sheet, where the scale of the sheet is 1:1,000,000 or 1 cm : 10 km ; there are total of 36 of these sheets covering the entire country.

2. The quarter inch sheet has a scale of 1: 250,000 or 1 cm : 2.5 km, each of these sheets is numbered separately from A to P.

3. The one inch sheet has a scale of 1 : 50,000 or 2 cm : 1 km.

In a grid system of a topo sheet, the lines that run vertically across a topographical map are called eastings. They are measured eastwards from the origin of the grid. In a grid system of a topo sheet, the lines that run horizontally across a topographical map are called northings. They are measured eastwards from the origin of the grid in northerly direction.

Nucleated settlement : 

1. The buildings and huts are in compact cluster. 

2. These are mostly found in plains or river valleys. 

3. These are also called as clustered settlements. 

4. The land is fertile and good for agriculture. 

5. The generally have a well- knit and large community. 

6. They have dense population. 

7. Essential facilities like hospitals, schools, police stations, post offices, etc are found 

8. Proper communication lines such as roads and railways lines are present. 

Scattered settlement : 

1. The houses and huts are far apart from one another. 

2. These are mostly found in hilly areas, thick forests and regions of extreme climate. 

3. These are also called as dispersed settlements. 

4. The land is not very fertile. 

5. They don’t have a very close-knit large community. 

6. They have sparse population. 

7. Essential facilities like school hospital, police station, etc. are not found. 

8. Proper roads are absent houses are connected by cart tracks or paths.

Settlements are groups of houses, usually in villages or towns, where people live. The size of settlements depends on the availability of roads, railways, hospitals, police station, administrative buildings, etc. Settlements grow over a period of time. 

A settlement can be permanent or temporary. 

Temporary settlements : Settlements that are constructed and occupied for a short time are called temporary settlements. They are built by people engaged in hunting and gathering, shifting cultivation and transhumance. Tents and huts are the most common forms of shelter in temporary settlements. In urban area, it is built next to a construction site such as a bridge or a flyover. A temporary settlement can become permanent with time. 

Permanent Settlements : In this, people build permanent houses. With time, several such structure develop and form a settlement. The availability of water and land for cultivation are important reasons for such settlements growing. Other factors are communication lines such as roads and railways, police stations, post office, hospital, market, health center, etc.

Some basic characteristics of contour lines are : 

1. Contour lines are drawn at fixed intervals, for example 20 m. This is called Vertical Interval (V.I). 

2. Contour lines do not intersect each other. They could meet and touch but not cross one another. 

3. On a topographical map, every fifth line is accentuated or drawn thick. This is known as contour index. 

4. The spacing between the contour lines determines the nature of the slope. Close contour lines indicate steep slope and far apart indicate gentle slope of land. Contour lines drawn at equal intervals indicate that the slope is neither steep nor gentle but is a uniform slope.

1. Black stream — It indicates that the stream is dry and has no water.

2. Blue stream — It indicates that the stream has water.

3. Green area — I indicates vegetation, mainly forests.

4. Yellow area — It indicates the area of cultivated land.

5. White area — It indicates barren land. No crops are grown in this land.

Vehicles such as trucks, buses, cars, jeeps, and other modem means of transport move over metalled roads. There are also cart tracks, pack tracks and footpaths, which are unmetalled roads. Cart tracks and pack tracks connect small village settlements in rural areas.

On the topographical map these water bodies are shown in black colour. 

1. Dry Nadi

Topographical maps are large scale maps that show both natural features (such as mountains, hills, rivers, plateaus, ridges, etc) and human-made features (such as roads, railway tracks, temples, bridges, buildings, etc).

4. vegetation

The contours for this feature are oval

3. ridge

This feature can be identified by a drop in height of the contours. 

3. col 

False.

A contour lines is an imaginary line that connects all points having the same height.

False.

The lines that run vertically are called eatings.

False.

The triangulated stations is indicated on the map with a small triangle followed by the number.

Contour lines are drawn at fixed intervals.

True.

1. conical hill

The difference in height between two adjacent contour lines is known as the Vertical Interval (V.I.). Whereas the distance between any two adjacent contour lines is called the Horizontal Equivalent (H.E.). The Horizontal Equivalent is calculated with the help of the scale of the map. The value of the H.E. is less when the slope is steep and more when the slope is gentle.

Linear settlements are those settlements that develop in a line. Houses, shops, dhaba’s, petrol pumps and garages develop along the sides of the roads, railway lines or river banks. Gradually, these linear settlements grow in size. These settlements gradually develop into trading centres. Examples: 

1. If such a settlement is near a railway track, and over a period of time, a need for a railway station is felt, then it becomes a railway stop. 

2. hen located on main roads, such settlements become important stops for travellers as dhabas, tyre and car repairing shops and petrol pumps open up. 

3. On rivers and coasts, they become places where boats can unload goods and passengers.

On a topographical map you will notice some black lines that cross the map. These lines are symbols of roadways and railway tracks and indicate the type of communication in the area. They depict the various modes of transport being used in the area. 

Communication and transport lines indicate the importance of a place. When many roads and railway lines converge in a village or a town, it indicates the importance of a place. It could be for several reasons such as the economic activity of the region or the region could be a tourist hot spot of it could be because of the presence of industries and factories leading to plenty of job opportunities. Airports are also an important form of travel and communication but airports are confined to large cities only. The conventional sign of an aeroplane indicates the presence of an airport or an airstrip.

Many factors determine the location and the type of settlements: 

1. Settlements grow in areas that are flat and where the land is cultivable. Settlements do not grow on steep hillsides or marshy lands. 

2. Settlements grow in places where water is available in plenty for both agricultural and domestic purposes. Settlements, therefore, also grow on the confluence of rivers or the banks of rivers. 

3. Settlements also thrive on a plateau because of the flat surface of the plateau and the availability of land for cultivation. 

4. They develop and grow in places where the climate is suitable or pleasant to live in. Extremely hot, cold, wet or dry places are not attractive settlement sites. 

5. Settlements are formed where there are prospects for employment. Mines and industries in the area are potential sources of employment and encourage growth of settlements. Such places are usually near places of abundant raw materials for the growth of industries. 

6. They develop in places that are easily accessible by various kinds of roads, rivers, and railway lines. Easy access to and from the settlements will allow movement of people and goods from one place to another.

Features of the grid system : 

1. The lines that run vertically are called eastings and those that run horizontally are called northings. 

2. Eastings and northings cross each other to form a square called as a grid square. 

3. The starting point or the reference point is the exteme south-west grid or the one at the bottom left corner. 

4. The numerical value of eastings increases eastwards beginning from the southwest corner. Similarly, the numerical value of northings increases northwards. 

5. Eastings and northings are always given in two digit numbers. Even 0 is read as 00. (For example, 01, 02, 03, 98, 99.) 

6. When referring to a grid, eastings are always stated first. 

7. Eastings and northings on a topo sheet drawn on a scale of 1 : 50,000 are always 2 cm apart, which means they represent a distance of 1 km on the ground. So, the area of 2cm × 2cm on the map represents 1 km × 1 km on the ground. 

8. There are two types of grid references :

(a) The four – figure reference

(b) the six-figure reference.

The vertical distance between two consecutive contour lines on a topographical map is called as Vertical Interval (VI). They are drawn at fixed intervals and do not change on the map. This interval depends on the scale of the map and the range of elevation in the area of the map. 

Example : VI in all topo sheets of 1 : 50,000 is 20 m.

Some of the elements of a topo sheet are : 

1. Sheet number — This number refers to a specific geographical area. It is written on the top of the sheet. 

2. Scale — The scale is not the same for all maps. It can be 1 : 10,00,000 1 cm : 10 km], 1 : 250,000 [i.e. ; 1 cm = 2.5 km] or 1 : 50,000 [i.e. 2 cm = 1 km] It is written at the bottom of the sheet. 

3. Grid — The sheets have grid lines in red called eastings and northings which help in locating places easily. 

4. Direction on map sheet — The top half of a topographical map is always the north and the bottom half is the south. The right hand is the east and left hand is the west. The eastings and northings are read from the southwest corner. 

5. The eastings and northings — Their numbers should be remembered before reading a map. 

6. Four-figure grid reference and six-figure grid reference squares — The fourfigure grid reference will have four digits and six-figure grid reference will have six digits. 

7. Legend and keys — Legends contain conventional signs and symbols in the form of keys. They provide the vital information to interpret the map correctly. 

8. Contour interval — (Vertical interval) It is the vertical distance between two consecutive contour lines. It remains same for a given scale of topo sheets. 

9. Spot heights — These indicate the actual elevation of a spot above mean sea level. 

10. Triangulated stations — These also indicate the height on maps. They are indicated on the map with a small triangle followed by the number. 

11. Contour index — Every fifth contour line is bolder than the other lines for easy identification of contour lines. 

12. Places marked with letters DEP (depression) indicate land at a lower level than the surrounding area. 

13. Dry and wet streams — On the map, black streams are dry and blue streams have water. 

14. Contour features — Like saddle, hill, pass, gentle and steep slope, ridge, etc can be seen on topo maps.

15. Colours — Green coloured area contains vegetation and forests, yellow coloured area is cultivated land and white portion is barren land.

Some of the elements of a topo sheet are : 

1. Sheet number — This number refers to a specific geographical area. It is written on the top of the sheet. 

2. Scale — The scale is not the same for all maps. It can be 1 : 10,00,000 1 cm : 10 km], 1 : 250,000 [i.e. ; 1 cm = 2.5 km] or 1 : 50,000 [i.e. 2 cm = 1 km] It is written at the bottom of the sheet. 

3. Grid — The sheets have grid lines in red called eastings and northings which help in locating places easily. 

4. Direction on map sheet — The top half of a topographical map is always the north and the bottom half is the south. The right hand is the east and left hand is the west. The eastings and northings are read from the southwest corner. 

5. The eastings and northings — Their numbers should be remembered before reading a map. 

6. Four-figure grid reference and six-figure grid reference squares — The fourfigure grid reference will have four digits and six-figure grid reference will have six digits. 

7. Legend and keys — Legends contain conventional signs and symbols in the form of keys. They provide the vital information to interpret the map correctly. 

8. Contour interval — (Vertical interval) It is the vertical distance between two consecutive contour lines. It remains same for a given scale of topo sheets. 

9. Spot heights — These indicate the actual elevation of a spot above mean sea level. 

10. Triangulated stations — These also indicate the height on maps. They are indicated on the map with a small triangle followed by the number. 

11. Contour index — Every fifth contour line is bolder than the other lines for easy identification of contour lines. 

12. Places marked with letters DEP (depression) indicate land at a lower level than the surrounding area. 

13. Dry and wet streams — On the map, black streams are dry and blue streams have water. 

14. Contour features — Like saddle, hill, pass, gentle and steep slope, ridge, etc can be seen on topo maps.

15. Colours — Green coloured area contains vegetation and forests, yellow coloured area is cultivated land and white portion is barren land.