NCERT Book Class 11 Geography Topographical Maps

International Map Series of the World: Topographical Maps under International Map Series of the World are designed to produce standardised maps for the entire World on a scale of 1: 10,00,000 and 1:250,000.

Reading of Topographical Maps: The study of topographical maps is simple. It requires the reader to get acquainted with the legend, conventional sign and the colours shown on the sheets. The conventional sign and symbols depicted on the topographical sheets are shown in Fig. 5.2 (on page 52). GlossaryContours: Imaginary lines joining all the points of equal elevation or altitude above mean sea level. They are also called “level lines”. Contour Interval: Interval between two successive contours. It is also known as vertical interval, usually written as V. I. Generally, it is constant for a given map.

Cross-section: A side view of the ground cut vertically along a straight line. It is also known as a section or profile. Hachures: Small straight lines drawn on the map along the direction of maximum slope, running across the contours. They given an idea about the differences in the slope of the ground. Topographic Map: A map of a small area drawn on a large scale depicting detailed surface features both natural and man made. Relief in this map is shown by contours.

METHODS OF RELIEF REPRESENTATION

The earth’s surface is not uniform and it varies from mountains to hills to plateaus and plains. The elevation and depressions of the earth’s surface are known as physical features or relief features of the earth. The map showing these features is called a relief map.

EXERCISE

1. Answer the following questions in about 30 words:

(i) What are topographical maps?

(ii) Name the organisation which prepares the topographical maps of India.

(iii) Which are the commonly used scales for mapping our country used by the Survey of India?

(iv) What are contours?

(v) What does the spacing of contours indicate?

(vi) What are conventional signs?

2. Write short notes on—

(i) Contours

(ii) ‘Marginal Information’ in Topographical sheets

(iii) The Survey of India

3. Explain what is meant by ‘map interpretation’ and what procedure is followed for its interpretation.

4. If you are interpreting the cultural features from a topographical sheet, what information would you like to seek and how would you derive this information? Discuss with the help of suitable examples.

5. Draw the conventional signs and symbols for the following features—

(i) International Boundary

(ii) Bench Mark

(iii) Villages

(iv) Metalled Road

(v) Footpath with bridges

(vi) Places of Worship

(vii)Railwayline

Exercise A

Study the contour pattern and answer the following questions.

1. Name the geographical feature formed by contours.

2. Find out the contour interval in the map.

3. Find out the map distance between E and F and convert it into ground distance.

4. Name the type of slope between A and B; C and D and E and F.

5. Find out the direction of E, D and F from G.

Exercise B

Study the extract from the topographical sheet No. 63K/12, as shown in the figure below and answer the following questions—

Please refer to attached file for NCERT Class 11 Geography Topographical Maps