1. F.1 Social Studies
Enrichment Program 4

2. A point is written along each contour showing its heights
Contours are lines joining places with the same height above the sea level.
contour line.
contour map
A point is written along each contour showing its heights

3. Vertical Intervals of the map
Interval: the distance between two things
The difference in height between two adjacent contours is called Vertical Intervals (V.I.) of the map.

4. Put in the correct height values of contours in the blank

5. Cross section
It is supposed a hill has been cut vertically, then we can see the side view, or cross section of the hill
A section is a slice vertically down through the land.
A cross section shows the shape of the lands.

6. Drawing a cross section
First draw a line on the contour map from Point X to Point Y.

7. Drawing a cross section
Mark all the contour lines and their heights between the two points
Take a piece of paper and mark point X and point Y on the edge of the paper

8. Drawing a cross section
Insert the scale and unit on X axis and Y axis. M

9. Drawing a cross section
Plot all the points. M

10. Drawing a cross section
Join all the points with a smooth line. M
Do not forget to put down a title
The hill

11. Gradient
Gradient is another method to find the degree of steepness of a slope. It is obtained by using the formula:
Vertical Interval (V.I.)
Horizontal equivalent (H.E.)
Horizontal distance between the bottom of slope and the top of the slope. It is called Horizontal Equivalent

12. Gradient The gradient of AB: 600m-200m (V.I.) 4.2 X 100m = 400m 420m=
1.05
We call it 1 in 1.105

13. Gradient The gradient of CD: 500m-200m (V.I.) 2.8 X 100m = 300m 280m=
0.98
We call it 1 in 0.98
Therefore, CD is steeper than AB

14. Gradient When contour lines are close together, the slope is steep.
When contour lines are far apart, the slope is gentle.