Potential landfill sites selection using GIS-based multi-criteria decision analysis in Dodoma capital city, central Tanzania

Abstract

Solid waste management is a global challenge, especially in developing countries due to the rapid increase in population and urbanization where the availability of sanitary landfills is inevitable. Determining suitable landfill sites is a fundamental aspect for new and rapidly growing cities. The current study is aimed at selecting potential landfill sites using GIS-based multi-criteria decision analysis in Dodoma capital city. Fifteen criteria including proximity from built-up areas, surface water, boreholes, sensitive sites including social service areas, episodic water channels, protected areas including historical sites, faults, land use/land cover, geology, soil type, elevation, slopes, airport, roads, and earthquake epicentres were integrated with the help of analytical hierarchy process (AHP). The landfill sites' suitability map was produced based on the weighted linear combination method and assigned suitability classes as highly suitable, suitable, moderately suitable, less suitable, and unsuitable. The overall suitability results show that 41,177 ha (14.7%) of the study area is determined as highly suitable for landfills site location. The remaining 83,930 ha (30%), 84,305 ha (30.2%), and 53,508 ha (19.1%) of the area are suitable, moderately suitable, and less suitable respectively while 16,683 ha (6%) is under the unsuitable zone. From the highly suitable area, eleven candidate landfill sites were selected and prioritized using the AHP technique. The final results show landfill site 3 (10,361.94 ha), 5 (3717.85 ha), and 2 (3535.86 ha) were found to be the most highly suitable sites with eigenvector weight of 0.147, 0.122, and 0.121 respectively. Landfill sites 8, 7, and 6 were lastly considered. Field observation involving expertise from geology, hydrogeology, geophysical, and environment confirmed the suitability of selected sites. Thus, these techniques can be employed in developing countries to locate suitable landfill sites to minimize health and environmental impacts.

Application of GIS-based multi-criteria decision making analysis (GIS-MCDA) in selecting locations most suitable for siting engineered landfills – the case of Ashanti Region, Ghana

“…For example Asori et al (2020) used AHP based GIS-MCDA to model wildfire risk in northern Ghana, Dumedah et al (2021) also utilized AHP based GIS-MCDA to spatially target groundwater vulnerability to pollution in Ashanti Region, Ghana and achieved considerable accuracy. It has also been used extensively in selecting landfill sites (Chabok and Asakereh, 2020;Makonyo and Msabi, 2021;Sisay et al, 2021) and to model flood susceptibility (Nachappa et al, 2020). In this current study, we adopted the AHP approach to characterize different variables (Table 3 and Figure 2) for easy integration in GIS environment, in order to compute and select appropriate zones for siting landfills in Ashanti Region of Ghana.…”

“…Therefore, each factor was assigned an objective Selecting areas suitable for siting landfills relative weight showing its comparative importance to help us decide where to situate the landfill using the AHP method described in section 2.2.1.1. It has been used successfully in other applications such as groundwater resources management (Al-Mallah and Al-Qurnawi, 2018; Anornu and Kabo-bah, 2012;Lima et al, 2011;Rana et al, 2020;Samake et al, 2011) and siting landfills (Ghobadi et al, 2013;Makonyo and Msabi, 2021). In this study, variables were weighted on the basis of their relative importance to the goalsiting engineered landfill.…”

“…, 2011) and siting landfills (Ghobadi et al. , 2013; Makonyo and Msabi, 2021). In this study, variables were weighted on the basis of their relative importance to the goal – siting engineered landfill.…”

“…One of the key challenges confronting both less and developed countries is solid waste management (Fagbohun and Aladejana, 2016; Chamchali and Ghazifard, 2021; Makonyo and Msabi, 2021; Callas et al. , 1996).…”

Landfill Site Selection Using GIS Based Multicriteria Evaluation Technique in Harar City, Eastern Ethiopia

“…After reviewing works of literature, the criteria selected were presented with fixed suitable buffers in Table 1. 13,[32][33][34][35][36][37][38][39][40]…”