Drawing of Contours and Their Cross Sections

The figure below illustrates how two adjacent hills are represented by contours.

a) Two adjacent hills shown by contours

Drawing cross-sections of contours helps in understanding the precise landforms depicted on the topographic sheet.

To draw a cross-section:

1. Identify the area on the map where you want to draw the cross-section.
2. Draw a straight line (AB) across the contours to indicate the path of the cross-section.
3. Below the line AB, draw horizontal lines at regular intervals, representing the elevation levels indicated by the contours.
4. Mark the elevation values on these horizontal lines, starting from the lowest elevation at the bottom.
5. For each contour line that intersects line AB, mark the corresponding elevation on the vertical lines.
6. Connect the points marked on the vertical lines to outline the shape of the landform.
7. Shade the area between the outline and the line AB to represent the landform in the cross-section.

General instructions for identifying features shown in contours:

• A hill is depicted by circular contours with heights less than 1,000 meters.

• A plateau is an elevated land with an innermost contour roughly rectangular in shape and closely spaced outer contours.

• A ridge is a steep-sloped, elongated mountain with two or more peaks, shown by elliptical contour lines.

• A valley is a long depression with steep slopes formed by river erosion, depicted by contours bending sharply in a ‘V’ shape across the river.

• Spurs are land projections from higher to lower ground, with contours bending smoothly towards lower ground.

• Waterfalls are represented by contours meeting at the same point on a hill slope, with the difference between the highest and lowest contours indicating the waterfall’s height.

• A cliff is a steep-sloped exposure of a valley or coast, while a gorge is a very steep valley formed by river erosion.

• A volcano is shown by closed contours, with the innermost contours having lesser values, denoting the crater depression.

Class 11 Geography Methods of Relief Representation Notes: Methods of Relief Representation is the fifth chapter in CBSE Class 11 Geography, which discusses the concept of topographical Maps and their various forms.

In Class 11 Geography, we learn about different ways to show the shape and features of the land on maps. These methods are important because they help us understand how the land looks. One way is using contour lines, which connect points of the same height on a map. Another way is shading, where we use different colours to show how light and shadow fall on the land. We also use short lines called hachures to show steep slopes and valleys. By learning these methods, we can better understand maps and the land they represent.

The Methods of Relief Representation notes cover all the necessary topics that are extremely important for the examination 2024. It can save you time and will positively affect your results.