Abstract:
Improperly placed solid waste dumping sites have created numerous environmental and
social problems in the society. Such impacts could be minimized by implementing proper
landfills in suitable locations. Even though Matara is a highly populated district, it lacks
properly planned landfills. The objective of this study was to select suitable sites for solid
waste landfills in the Matara District using the Geographic Information System and the
Analytical Hierarchy Process. Existing national and international landfill site selection
regulations and guidelines were reviewed to prepare eleven landfill site criteria namely;
surface water body, forest reserve, wetland, coastal zone, rainfall, town centre, residential
area, important building, major road and railway, slope and soil. These criteria were divided
into two parts, constraint criteria and factor criteria. Constraint criteria divide the district into
suitable and unsuitable areas for landfill site placement. Factor criteria classify the suitable
areas for landfill placement into high, medium and low suitable areas. Each constraint
criterion was mapped using GIS. All eleven constraint criteria maps were overlaid to prepare
the final constraint map. From the total area of Matara district, 1100.16 km2 (85.7%) is
unsuitable for landfill placement. The remaining 182.34 km2 (14.2 %) land area of the district
was further evaluated using factor criteria and was classified into three groups of high,
medium and low suitability. When determining the relative importance of each factor criterion
Analytic Hierarchy Process was utilized. The resulting final factor map revealed that 112.4
km2 (8.8%) of land in the Matara District is highly suitable for placing landfills. Field
investigations within the Matara Divisional Secretary Division were carried out to validate the
data obtained from the final factor map. It was found out that one site at Thalpawila, one site
at Parawahera and two sites at Kekanadura were suitable for landfills in Matara Divisional
Secretary Division. The final decision for landfill site selection will require more detailed field
studies.
