Abstract:
Wetlands are characterized by a unique combination of water, soil and vegetation. They are
among the most productive and important ecosystems on earth which render significant
ecosystem services to the community. Water and vegetation in and around wetlands help in
regulating the microclimate, specially lowering the temperature in the local environment.
The present study attempted to investigate the cooling effects provided by Anawilundawa, a
Ramsar site in Puttalam District where diverse land uses exist surrounding the wetland. Land
Surface Temperature (LST) variation above different land use classes was investigated during
the dry months of January, February, June and July of 2016 and 2020 in natural (water bodies,
marsh, thick vegetation, grassland) and anthropogenic areas (built-up areas, coconut cultivation
and bare lands). The LST values were obtained at 500m points along seven transect lines
starting from the center of the water body and extending up to 7km over different land use areas
and reaching towards the anthropogenic area.
The mean LST over the wetland (24.10°C) was significantly lower than that of anthropogenic
areas (25.01°C) (P<0.05). The temperature range, mean ± standard deviation for different land
use areas were as follows: water body (23.21°C-24.67°C; 23.89°C±0.58), marsh (23.49°C-
25.94°C; 24.57°C±1.02), thick vegetation (22.99°C-25.03°C; 24.04°C±0.56) grassland (23.18°C-
25.93°C; 24.36°C±0.77), built up area (24.00°C-28.32°C; 25.40°C±1.40), coconut cultivations
(23.19°C-24.23°C; 23.93°C ±0.38) and bare land (24.54°C-26.39°C; 25.29°C ±0.60). The lowest
increase of LST was over the water body (+1.13°C) and the highest was over the built-up area
(+4.32°C).
Findings of this study presents important implications for policy makers to conserve wetlands
for community well-being especially during the dry season and for climate change adaptations.
