The environmental chemistry of rainwater in Sri Lanka

Rainwater samples collected from different parts of Sri Lanka have been analyzed for their chemical constituents. It was observed that except for minor occurrences, “acid‐rain” is still not prevalent in Sri Lanka. Based on the chemical composition, the rainwater of Sri Lanka has been classified chemically into eight different types, the most dominant being Ca/Mg—HCO3, Ca—Cl and non‐dominant cation—HCO3 types. The wet zone of Sri Lanka, particularly the areas around the central highlands, form a special zone in that a number of chemically different rainwater types can be found in these regions. In contrast, the dry zone of Sri Lanka receives four distinct types of rainwater and conform to geographical zones.