Drainage patterns in Africa
Drainage pattern refers to the arrangement/lay out/plan of the river and its tributaries.The way tributaries are laid out is usually influenced by geological history of the drainage basin and precipitation. The main types of drainage patterns include:
Dendritic drainage pattern. This is a type of drainage pattern which resembles the branches of a tree. The river tributaries join the main river at acute angles. Process of dendritic drainage pattern development: There must be a consequent river [Main River] where insequent (minor) streams develop from the main river by head ward erosion.
The minor streams may also develop from insequent streams as obsequent streams. Finally, the pattern of drainage develops resembling the branches of a tree.
Give examples of the dendritic drainage pattern and draw the Illustration
Radial drainage pattern
Here rivers originate from one central area and flow outwards from the highland to lowland. It is controlled by slope of the land and rivers start from mountain areas and flow down slope. The minor stream flows in accordance with the slope direction, obsequent streams; flow in opposite direction to the slope joining other streams at right angles.
Give Examples of radial pattern in Africa and draw the Illustration
Centripetal drainage pattern
Here rivers flow from different directions and converge into one place which is a basin. Centripetal drainage is guided by the slope of the land. Areas with centripetal pattern are areas of inland drainage. Give Examples of centripetal pattern in Africa and draw the Illustration
Parallel drainage pattern
Here the river flows for a long distance parallel to each other. It is a common pattern in ridges or escarpments and also where alternating hard and soft rocks downstream. Research work: Other drainage patterns include Annular Drainage, Rectangular pattern