Abstract:
Economy of Sri Lanka, in general and Eastern province in particular, is
largely depends on agriculture. Ampara is one of the most productive rice producing
regions in Sri Lanka. The Gal-Oya River flows through the lowlands of the south-east
coast of Sri Lanka and is predominately surrounded by rice paddies. The irrigated
agriculture is at a high risk of excessive nutrient inputs due to the high application rates
of nitrogen fertilisers used by Sri Lankan farmers. A baseline assessment of water
quality was conducted in the Gal-Oya, with four sampling surveys in total. Two
sampling surveys occurred during the dry season, one during the inter-monsoonal
season and one during the monsoonal rains. Standard physical-chemical parameters
were measured in situ and samples were taken for chemical analysis of free-nitrate,
reactive-phosphate and suspended solids. The monsoonal rains were associated with
dramatic increases in free-nitrate concentrations and suspended solids. This baseline
study reveals the need for further investigations into the impacts associated with large-scale
agriculture along the east coast of Sri Lanka. Water quality monitoring programs
have been severely restricted along the East coast of Sri Lanka since the onset of the
conflict between separatist and government forces in 1983. This monitoring programme
represents the first major water quality assessment to be conducted for over two decades
on the Gal-Oya.
