Credits: Biovision-Infonet
Although it is known that clouds can be seeded with chemicals to produce rains, the practice is expensive and unsustainable.
It should therefore be realized that rainfall varies from region to region and from one year to another beyond peoples’ manipulation and interference.
All fresh water comes from rains, including water in deep boreholes which originates from rains infiltrated into the underground thousands or millions of years ago.
Fresh water can only be obtained from four main sources; rainwater harvesting, shallow ground water, deep ground water and desalination of which the two latter options are too expensive to be discussed here.
The North-East monsoon coming from India brings rains to East Africa from October to December every year.
The South-East monsoon brings rains from March to June. Rain falls where and when the two monsoons meet.
The area of convergence is called the Inter-Tropical Convergence Zone. This zone follows the apparent movement of the sun, north and south, bringing rain in its wake.
But the pattern is influenced by mountain ranges, Lake Victoria and periodic westerly winds from the Atlantic.
The two monsoons bring an annual average of about 600 mm rainfall to the semi-arid eastern and northern parts of Kenya, while the highland zone at Mount Kenya has a mean average of 1,000 mm and the Lake Victoria zone has a mean average of 1,800 mm.
The rainfall pattern of East Africa is also presented as a map with different colours for the various average annual rainfalls.