GCE O - LEVEL GEOGRAPHY MAP READING

Relief features are presented on maps by the help of contours drawn in different shapes, forms, pattern and spacing representing different relief features. Relief is the inequality of land or the undulating nature of the land surface. Candidates have to master the way r manner in which the various features are presented by contours. This is because most multiple choice questions shall be asked on different features as presented by the contour lines. Features presented by contours include; cliff, escarpment, valley, spur etc.

Relief features 

REPRESENTATION OF RELIEF FEATURES BY THE USE OF CONTOUR LINES

A CLIFF

This is a land that rises sharply or steeply from the sea or it is a steep slope over looking a sea or a big river. A cliff is represented and can be identified by close contours running together which may merge up at certain points. 

An Escarpment or  Scarp

This is a slope with steep face ( scarp face ) and a gentle back slope. It arises from differential erosion or from faulting. the scarp slope which is the steeper slope and the gentle slope which is called the dip slope combine to form what is called a CUESTA. Other names for escarpment are scarp face or scarp slope.

A Valley 

This is a low land in between high lands, most often occupied by streams. However, we sometimes have dry valleys. A valley is shown with contours which are V-Shaded with the apex pointing towards the highland. There are various types of valleys, broad valleys, dry valleys and narrow valleys.

The valley is pointing to the highland as shown by contours in diagram above

A Spur

This is a high land projecting into a river valley or a lowland. the contours are also shaped but pointing towards the low lands. They are high lands between valleys.

A GORGE

This is a steep sided narrow valley. It is also known as a canyon in the desert region where it size is considerable large. A river often flow inside it. It is represented by very close contours running parallel to the river course.

Conical Hills 

These are round top hills which are represented by concentric or circular contours. If the contours are close.

A Ridge 

This is a narrow elongated stretch of up land. The vary in forms, and size. Ridges are shown by contours which are close together and showing an elongated pattern. The contour rise on surrounding lowlands. Many other different features may be found on a ridge such as saddle, col, pass or gap 
i) Saddle: This is a wide or broad depression separating two high grounds or summits on a highland. It is important for road construction.
ii) Col: This a shallow depression separating two summits. Not as broad as a saddle it is also good for road construction.
iii) A Pass or Gap: This is a very deep depression on a highland with the land on both sides of it standing very high with steep slopes.