(a) Description of Stages of Development of a River
Upper course / Torrent stage / Youthful stage
— This section or stage of the river occurs near the source of mountain area.
— The river flows swiftly as it descends the slope of the mountain.
— The river is very active in vertical corrosion
— Down cutting of the river bed occurs more rapidly than lateral erosion The main features produced include river capture, narrow steep-sided (v-shaped), valleys, rapids and waterfalls, potholes, interlocking spurs gorges, plunge pools, etc.
Middle Course / Valley Course / Maturity Stage
— It has a gentle gradient
— It widens its valley
— lateral erosion becomes dominant
—The velocity is reduced due to the reduction of gradient.
— Transportation of the river's loads is more in the form of suspension and solution.
— Deposition begins to take place at valley sides and floor.
— The main features produced are wide floodplain, levees, delta, braided stream, -Ox-bow lakes, etc.
(b)Importance of Rivers to Man
— Medium of transportation
— Generation of hydro - electric power (H. E. P)
— Water for irrigation purposes
— Water for domestic purposes e.g Washing, cooking, drinking, etc.
— Water for industrial uses
— Fertile soil for agricultural activities
— Used as political boundaries for towns, states nations
— Source of fish
— For recreation
— Source of minerals e.g alluvial gold, diamond, etc.