The Democratic Socialist Republic of Sri Lanka, located off the southeastern coast of India, covers an area of 65 610 km2 between latitudes 5° 55´ and 9° 55´ N and longitudes 79° 41´ and 81° 54´ E. The Palk Strait and Gulf of Mannâr separate Sri Lanka from India. The coastline is about 1 600 km long, broken by extensive salt-water lagoons and bays. Administratively, it is divided into 9 provinces that are further divided into 24 districts. It has two main physiographic zones:
- The highlands lie in the central and south eastern parts of the island, rising to elevations higher than 2 000 m. All the rivers of the country originate in this area and radiate toward the coast. It consists of a high core flanked on all sides by lower valleys and plateaus.
The main physiographic subdivisions within the highlands are the high plains and the ridges radiating from Pidurutalagala Peak (2 524 m), the Knuckles ranges, the Uva basin, the Horton plateau, the Lunugala ridges and the Sabaragamuwa ridges;
- The western lowland plains cover the entire northern half of the country. In the east, south-east and south-west they are reduced to a narrow strip between the highlands and the coast. Their surface is level to undulating.
The climate is tropical and maritime. The mean monthly temperature varies from 30° C in the lowlands to 20° C in the highlands above 2 600 m. Most of the rainfall in the highlands is received through the south-west monsoon during the summer, from June through September. The north-east monsoon brings a fair amount of rainfall to the plains and a heavy rainfall to the eastern part of the central highlands.
Two other significant rainy periods occur in the spring, from March to May, and in the fall, from September to November. Sri Lanka can be divided roughly into a northern dry zone and a southern wet zone merging into an intermediate zone in between.
The dry zone occupies almost two thirds of the country and consists mainly of flat and undulating land where major irrigation schemes are in operation and the bulk of the agricultural and forestry activities take place. Annual rainfall varies from 750 mm to 1 850 mm. The wet zone has an annual rainfall ranging from 2 500 mm to 5 000 mm. It occupies the south-eastern regions and consists of a narrow coastal plain and very rugged mountainous areas reaching 2 750 m. Rainfall is abundant throughout the year.
The soils belong to two categories, those derived from the parent material and their erosion products and those derived from transported materials. The former are generally clayey soils whereas the latter are light sandy loams.
The designations employed and the presentation of material in this publication do not imply the expression of any opinion whatsoever on the part of the Food and Agriculture Organization of the United Nations concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries.