Environmental assessment for wetland management in Sri Lanka

Amarasinghe, MD

Abstract

The objectives of the study are to identify an appropriate environmental
assessment framework for the management of wetlands in Sri Lanka and to
determine its practicability under the prevailing conditions of data availability
and expertise.
Eight functions and values are used to characterize wetland environments and the
baseline conditions are evaluated by the capacity to perform each function.
Questionnaire checklists were used to screen the potential functions of wetlands.
Environmental parameters appropriate to predict the functional status were
identified and scaled-weighted checklists were adopted to ascertain their relative
magnitude. The relative contribution (weight) of each variable to the functional
capacity was determined using a pairwise comparison technique. The products
of scale and weight for each predictor variable of a function were added,
expressed as a percentage to the maximum possible functional capacity value and
then converted to a 1-10 scale.
Social significance of each function was determined using a questionnaire
checklist and interpretation keys and expressed in a 1-3 scale. The products of
percentage functional value and social significance values were aggregated to
derive a total wetland value. For comparison with other wetlands, total value
was expressed as a percentage overall value against a hypothetical 'super
wetland'.
Baseline data on Tabbowa, a man-made freshwater wetland in north western Sri
Lanka were collected and analyzed to test the applicability of the methodology.
It was found that secondary data gathered from various sources and the primary
data generated through field surveys were sufficient to evaluate the major
wetland functions.
Impacts of a proposed reclamation project on Muthurajawela/ Negombo Lagoon
tidal wetland, on the west coast of Sri Lanka, were assessed by determining the
change in wetland value with the project. Impacts were identified using network
analysis and an alternative reclamation site was evaluated by comparing the
aggregate percentage impact on the wetland functional capacity.
Improvements to the existing EIA system in Sri Lanka are presented and further
enhancement in the process through economic evaluation methods is discussed.

Citation

Amarasinghe, M. Environmental assessment for wetland management in Sri Lanka. (Thesis). University of Salford

• Thesis Type: Thesis
• Deposit Date: Jul 22, 2021
• Additional Information: Funders : National Aquatic Resources Agency; Projects : Agricultural Research Project
• Award Date: Jan 1, 1994