D L O Mendis - ۱۶, Amerasekera Mawatha, Colombo ۵, Sri Lanka

Background: Sri Lanka is an island in the Indian ocean, located between 6 and 8 degrees latitude north of the equator, at the southern tip of the Indian sub-continent. It’s area is approximately 65,000 sq. kms or 25,000 sq. miles, and it experiences two monsoons, the northeast monsoon between October and March, and the southwest monsoon between April and September, with inte -monsoon rains as well. The southwest monsoon rainfall is largely intercepted by a south-central hill massif, and then blows over the northeast region as a dry wind, whereas the northeast monsoon rainfall is spread over most of the island. Consequently, a wet zone and a dry zone, with an intermediate zone lying in between, is recognized in the country today. In ancient times, however, there were three regions described as Rajarata (King’s country), Ruhunurata and Mayarata. On account of the rainfall pattern and the topography, many of the 103 rivers in Sri Lanka rise in the central highlands and flow in a radial pattern to the sea. Perennial rivers are called ganga, and non-perennial rivers and streams are called oya, ara or ela in Sinhala, (the Sinhalese constituting 74% of the population), and aru in Tamil. (Figure 1).