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(i) Distinguish between aridity and desertification
(ii) Explain any three physical causes of aridity and desertification

Answer Text:
i) Aridity is the state of land being deficient of moisture leading to scarcity/lack of
vegetation. while desertification is the slow but steady encroachment of desert-like
conditions onto formally productive agricultural land
ii) - Continentality/distance from the sea- Onshore winds drop most of their moisture along the coast reaching the interior as dry wind leading to aridity and desertification
- Relief barriers/Rain shadow effect - Rain bearing winds drop a lot of moisture on the windward side of mountains. They thus reach the leeward side of with less moisture as dry
winds causing aridity and desertification
- Cold ocean currents; where on shore winds cross over cold ocean currents, the moisture content of the winds is lowered by the chilling effect of cold currents, the winds thus drop moisture over the sea reaching the land as dry winds that cause aridity and desertification.
- High pressure systems- Areas with stable, high pressure systems with low humidity and descending air/diverging winds
experience aridity since moist air has to rise for condensation to take place.
- Dry wind system;- Hot and dry winds from land like the harmattan constantly blowing over some regions cause a drying effect the land resulting in development of arid conditions
- High temperature:- Areas constantly experiencing high temperature have high rates of evaporation leading to arid conditions
- Insufficient rainfall:- Areas that constantly receive rainfall less than 250mm annually have scanty vegetation, immature soils making the land barren