ICSE Questions & Answers: Topographical Maps
1. How to find out the different occupations from the topographical map?
Different colours signify different occupations. For example, Yellow (yellow wash) - agriculture; green (green wash) - forestry; white wash - grazing / mining (if kilns present); DB / PTO / Hospital - Government service.
2. Should we write the degrees along with the direction?
No, only mention the direction.
3. What are causeways?
Raised metaled roads across streams (not a bridge).
4. Are we allowed to make any markings on the maps?
You may but with a pencil. It is a good habit to erase off later.
5. What do QC and QD in toposheet represent?
These are used for grid reference and signifies an area of 100 km × 100 km.
6. When do we say relative height or depth for "r"?
The "r" written outside or inside a well without any embankment indicates relative depth. All others, like tanks with embankment, sand dunes, bank of the river, steep slope, etc. indicates relative height.
7. There is a blue line in the river so why is it not perennial?
It is a thin perennial channel of water. The river is non perennial. Otherwise the whole breadth of the river would have been coloured blue.
8. How do we find the direction of the flow of a river in a topographical map?
First see if an arrow is there. If found, the direction in which it is pointing, indicates the direction. Otherwise in the direction contours & spot heights are decreasing is the direction of flow of the river.
9. How can we distinguish between a Telegraph and telephone line from Tehsil Border at a place (as both the symbol seem alike)?
Telegraph and telegraph line is written.
10. Is it true that wherever there is a hill the pattern of drainage is radial?
Yes, as well as highland area like plateau, ridge surrounded by low lying areas.
11. How to find out sources of irrigation and type of climate over the given map?
Wells, tanks (conventional symbols), canal are sources of irrigation. Since it is part of India so climate will be Tropical Monsoon with seasonal rainfall.
12. What is the importance of Topographical Maps?
Topographical maps are used by engineers for making roads, buildings / settlements, railways, etc. They are also used in the defence sector and for navigation.
13. Are eastings and northings same as latitude and longitudes? If not why?
They are similar to them but they are not latitudes and longitudes. The latter is used for large areas to find location which is not possible for smaller areas in detail like topomaps. So, we use Eastings and Northings.
14. What role do the relative heights play in finding the direction of a river in the toposheet?
They do not play any role because it is not height above sea level.
15. What does 'LY' represent on the map?
It is the same as QC and QD. Used for grid reference and signifies an area of 100 km x 100 km
16. What is the difference between Linear settlement and Ribbon settlement?
They are the same.
17. What is the difference between contour lines and contour intervals?
Contour lines are imaginary lines joining places having the same height above mean sea level. The difference in height between two successive or consecutive contour lines is the Contour Interval.
18. What is the difference between lined and unlined perennial well?
Lined means cemented and mortared but unlined is not cemented. Pucca (lined) and Kachha (unlined) wells.
19. Why are topographical maps also known as Ordinance Survey Maps?
These maps were originally drawn in the U.K. by the Army personnel and used extensively by them. That is why they are so called.
20. How do we find the 4 figure grid of a particular symbol when it is placed between two boxes?
Both the boxes will be the correct answer. You may write either of these.
21. Why are Eastings and Northings so called?
Eastings progressively increases towards the east and Northings increases towards the north from the origin i.e. South West corner. that is why so called.
22. Can we write "Parallel" drainage pattern for trellised? If no, why?
No, parallel is the meaning of Trellised. Can write Rectangular.