ICSE Class 10 Geography Goyal Brothers Solutions Chapter 2 Interpretation of Topographical Maps 2
Exercise I
Question 1.
Define contour.
Answer:
Contour is defined as the an imaginary lines joining all places which are at the same height. The coast line is a simple example of a contour line since it joins all places at sea level. Contouring is the most widely used method of showing relief on the map.
Question 2.
What is hachuring used for?
Answer:
- Hachures are short lines used to representing the directions of a slope.
- For steep slopes they are drawn closer together than for the gentle slopes.
Question 3.
What is a gradient? How is it determined?
Answer:
Gradient or Slope is the ratio between the vertical interval and horizontal equivalent. To determined/calculated the gradient between two points marked on a map at first vertical interval is to be obtained by finding the difference in the value of the two points. Secondly, the horizontal equivalent would have to be calculated with the help of a scale. Then, the gradient can be determined by using the below-mentioned formula i.e. Gradient
\(\frac{\text { Vertical interval }}{\text { Horizontal equivalent }}\)
or
\(\frac{\mathrm{V} . \mathrm{I}}{\mathrm{H} . \mathrm{E}}\)
Question 4.
What are Form lines?
Answer:
Form Lines :
Form lines are contour lines, but show only approximate heights above sea level as they are used to indicate the elevations of the area which are not accessible for proper survey. Hence they are drawn as broken lines and are called
Question 5.
What are spot heights? How are they represented on the map?
Answer:
Spot Heights :
Spot heights are used to provide more information about land surfaces between the contours. These are represented by a number preceded by a dot.
Representation:
Look at the sample survey map which shows a number of dots with a number beside them, denoting the height of that point above mean sea level. For example, if the height of the place is 60 m, it is written as 60.
Question 6.
What is meant by Bench marks? How are they represented on the map?
Answer:
Bench Marks:
The marks inscribed stones or shown on buildings to indicate the exact height determined through the surveys, are called the Bench Marks.
Question 7.
What is meant by index contours 7 In what way are they useful?
Answer:
Index Contours:
To make the maps easier to read, contour lines are thickened at regular intervals. These thickened contour lines are called Index Contours.
Question 8.
Differentiate between vertical interval and horizontal equivalent?
Answer:
|
Vertical Interval (V.I.) |
Horizontal Equivalent (H.E.) |
| The vertical distance between any two contour lines is called Vertical Interval (V.I.). | The actual distance between two points on two contour lines is called Horizontal Equivalent (H.E.). |
Question 9.
What is a grid?
Answer:
A set of lines used to locate the places accurately on a map called a grid.
Or
The network of horizontal and vertical lines, or the Eastings and Northings, is called the grid.
Question 10.
What points should be kept in mind while reading a grid reference?
Answer:
The following points, should be kept in mind while reading the grid reference.
- Origin is the South-West (SW) comer of the map. The reading on the map is always taken with reference to this origin.
- Eastings are always read to the North of the origin.
- Northings are always read to the North of the origin.
- While giving a grid reference, Eastings are always stated first, followed by the Northings.
- The readings are always taken to the right of the Eastings and to the North of the Northings.
Question 11.
Identify and name the relief features represented in the grid diagrams, A, B, C, D, E and F.
Answer:
(A) Plateau
(B) A waterfall
(C) A Ridge
(D) A Gentle and Steep Slope
(E) A convex slope
(F) A concave slope
Exercise II
Question 1.
What is the direct distance of Karja from Rampura in kms?
Answer:
The distance of Kaja from Rampura is 4.2 cms.
Scale of the map:
2 cms = 1 km
4.2 cms = 2.1 kms.
Question 2.
What is the direction of Banas River? Give a reason for your answer.
Answer:
The direction of Banas river is from North East to South West. This is because the spot heights are receding from N.E. to S. W.
Question 3.
On which bank of the river is Arniwada situated? Give a reason for your answer.
Answer:
Arniwada is situated on the right bank of river Banas.
Question 4.
What is the area of the given survey sheet in kms?
Answer:
Area of the given survery sheet is Length × Breadth
Length of the map = 9 \(\frac{1}{4}\)grids
breadth of the map = 10 grids
Scale of the map is 2cm = 1 km
∴ Grid is = 2 cm or 1 km
Length = 9 × \(\frac{1}{4}\)grids×1km = 9\(\frac{1}{4}\)gridskm
Breadth =10×1 km = 10 km
∴ Area = 9 \(\frac{1}{4}\)grids× 10 = 92.5 sq. kms.
Question 5.
State the drainage pattern in grid squares 9574,9674 and 9675.
Answer:
- The drainage pattern in grid square 9574 is Dendritic.
- The drainage pattern in grid square 9674 is Trellis.
- The drainage pattern in grid square 9675 is disappearing.
Question 6.
(a) Give a four figure grid reference of the following –
(i) Broken ground
(ii) A survey tree
(iii) A col and spot height 381.
Answer:
The four figure grid references of the
- Broken ground is 9679
- A survey tree is 9873
- A col and spot height 3 81 is 9874
Question 7.
Explain the following terms:
(i) Disappearing stream
(ii) Broken ground
Answer:
(i) Disappearing stream –
The water of the streams or tributaries is absorbed in the soil before it joins the main river. Hence it seems as if the stream has disappeared, especially in the region of limestone rock. At times the river may flow underground and reappear again. Sometimes the scanty rainfall and early evaporation results in disappearing streams.
(ii) Broken ground –
Broken ground is caused by erosion during rain when the river is in flood. It is found along the banks of a river, the area devoid of vegetation.
Question 8.
State two man-made and two natural features in grid square 9282.
Answer:
The man-made features in Grid Square 9282 are temples, settlements, pack-track. And the natural features are Trees(vegetation), streams.
Question 9.
What does 16 r mean in grid square 9475?
Answer:
16 r in grid square 9475 means the height of sand dunes is 16 metres.
Question 10.
Measure the length of the metalled road shown in the S.E. corner of the map.
Answer:
The length of the metalled road in S.E. comer is 7.1 cms.
Scale of the map 2 cms = 1 km
Scale of the map 7.1 cms = \(\frac{7.1}{2}\) =3.55 kms.
Question 11.
What is meant by watershed or water divide?
Answer:
A watershed or water divide means “A ridge of highland dividing two areas that are drained by different drainage systems.”
Question 12.
Draw the conventional symbols in appropriate colours for the following:
(a) Causeway
(b) artificial tank with embankment
(c) broken ground
(d) Nucleated settlement
(e) Permanent hut.
Answer:
Exercise III
Question 1.
What are the means of transport shown in the S.E. Corner of the map?
Answer:
The means of transport shown in the S .E. Comer of the map are:
- Metalled roads
- Western Railway
- Cart Track.
Question 2.
Compare and contrast the area north and south of the Banas river. (Any two points).
Answer:
The area North of the Banas river are:
- Rocky are with sheet rock.
- Radial drainage pattern.
The area south of the banas river:
- Sandy area with many sand dunes.
- Disappearing streams.
Question 3.
What is the chief source of irrigation in the cultivable area of the survey sheet?
Answer:
The chief source of irrigation in the cultivable area is Wells.
Question 4.
What type of rainfall does the region receive?
Answer:
The region receives seasonal rainfall shown by broken grounds and dry streams.
Question 5.
Why is Chitrasani considered a well developed town as compared to Pirojpura?
Answer:
- Chitrasani is considered a well developed as it is connected with metalled roads and western Railways, having wells for irrigation.
- Priojpura is having sandy area and have only cart track.
Question 6.
Give four-figure grid reference of the following –
(i) Sheet rock
(ii) Open scrub
(iii) Linear settlement
(iv) Nucleated settlement
(v) Rock out-crop
Answer:
- Sheet rock: 9582
- Open scrub : 9573
- Linear settlement: 9282
- Nucleated settlement: 9576
- Rock out – crop : 9583
Question 7.
What is the direction of Antroli town from Arniwada?
Answer:
Antroli is situated South of Arniwada.
Question 8.
What is the scale of the given map?
Answer:
The scale of the map is 1:50000 i. e. 2cms to 1 km.
Question 9.
What is the occupation of the people in the north of Banas river? Give a reason for your answer.
Answer:
The Occupation of the people in the North of Banas river is forestry and Cattle rearing.
The vegetation grown or open scale show it.
Question 10.
Identify the conventional sign in red broken lines in grid square 9777.
Answer:
The conventional sign in red broken lines in grid square 9777 shows the pack track, which is only used by man and animals only.
Goyal Brothers Prakashan Class 10 ICSE Geography Solutions