The construction of a Geographic Information System (GIS) model for landfill site selection
In the past decade, locating landfill site has been recognized as a significant planning problem and has subsequently received much attention from researchers in the planning sector. In particular, the siting of landfills is becoming more of an issue due to the prevalent “not in my backyard” (NIMBY) and “not in anyone’s backyard” (NIABY) concerns from the public. The purpose of this study, after identifying important criteria for siting landfills, was to develop a user-friendly landfill site selection model using a Geographic Information Systems (GIS) framework. Due to unavailability of electronic spatial data for Lesotho, Bloemfontein area was used as a test case. The model is tested in Bloemfontein with the intension to be applied in the city of Maseru as soon as the spatial data become available. The three main objectives were to develop GIS criteria for locating the landfill, identify possible sites that were suitable for this type of development and evaluate the effectiveness of these GIS methods used in the study. Production of constraint and factor maps took place. Afterwards, final suitability map was created using ArcGIS analysis tools. The optimum suitability map indicated that there were more optimal sites found within Bloemfontein city. The results discovered in Bloemfontein city using the GIS-based study revealed that although highly suitable areas were limited, a site was still able to be chosen under the predefined parameters. The site is not located on, or near, any environmental interest areas and is located a significant distance away from streams and urban areas, which minimizes social conflict and environmental impacts. The site is also located close enough (1-2km) to major road (N8) to Kimberley from Bloemfontein city and railroad, which ensures that economic costs of implementation are minimal. The selected region has a slope less than 12%, which are both an infrastructural advantage and a means of minimizing environmental impacts. Furthermore, the landfill is located in an area within 22 kilometres of the Bloemfontein study area. Since the site is located in a highly suitable area, environmental, social, and economic concerns have been met. Ultimately, the study proposes an acceptable landfill site for solid waste, taking Bloemfontein as the test study area. This research will contribute in developing Lesotho’s spatial database of environmental and social information to assist in the formulation of environmental policy. It is also expected that such municipal GIS when planned and implemented efficiently with sufficient public awareness and support would be instrumental in bringing reforms at the local and national level, realizing a major improvement without much capital investment.