Normal Probability Plot
5. CHAPTER FIVE
5.3 Conclusion
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site location is found to be generally acceptable for around 67% of the area, while the other 33% is both permanently and currently unsuitable for landfill construction.
Table 5.8: The proportions of the suitability observed in the landfill site suitability map.
Factor Suitability scale Count Proportion
Weighted overlay map
2 less suitable 8134 1%
3 moderately suitable
243740 32%
4 suitable 473948 61%
5 highly suitable 45912 6%
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CHAPTER SIX: SYNTHESIS 6.1 Introduction
Solid waste management (SWM) is a global pandemic. The increase in solid waste (SW) generation due to a rapid rise in economic growth, urbanisation, and population growth is a challenge. Instead of creating a separate management system for each form of waste, this increase necessitates an integrated sustainable strategy that covers all waste streams. (Nadiri et al., 2018; Şener and Şener, 2020; Weldeyohanis et al., 2020; Xiao et al., 2020). The management of municipal solid waste (MSW) is going through a grave stage owing to the lack of suitable facilities for treatment and disposal of the rising quantity of MSW generated in cities (Sener et al., 2010). Understanding the nature of SWM generation, including its quantity, and composition is essential towards the sustainable SWM. This results in the design, implementation, and improvement of WM systems as they require appropriate alternative methods of handling and treatment (Abdel-Shafy and Mansour, 2018; Johnima et al., 2022; Papachristou, 2009). In addition, waste generation forecasting is necessary to make proper planning and formulation of relevant policy measures towards sustainable SWM. Furthermore, this information will assist in the selection of a suitable waste disposal site, which will enable proper planning of land use that will promote sustainable SWM disposal.Consequently, this current study aimed to investigate the management of SW in the Mankweng cluster and find a potentially suitable area for a SW disposal site. The objectives of the study were to:
i. Evaluate household solid waste management practices and perceptions in the Mankweng Cluster.
ii. Forecast the municipal solid waste generation in the in Polokwane Local Municipality, South Africa.
iii. Identify a potential suitable landfill site through site suitability analysis using Geographic Information System (GIS) and Analytical Hierarchy Process (AHP).
115 6.2 Summary of the results
6.2.1 Evaluating household solid waste management practices and perceptions.
The results revealed that the practices and perceptions variation on household solid waste management in the wards under study is influenced by the difference in SWM service delivery. The study has discovered that food waste was the highly generated waste in both wards. The estimated SW generation rate for ward 25 was 0.27kg/cap/day whereas in ward 27 is 0.13kg/cap/day. This might be due to household income differences, and lifestyle behaviour since ward 25 is semi-urban, while ward 27 is mainly rural settlement. Additionally, the household income difference in both wards has been shown to have a significant impact on the waste generation quantity.
According to Tsheleza et al. (2019), South Africa generated an average of 0.94 kg of MSW per day, ranging from 0.09 kg per day to 5.50 kg per capita per day. Additionally, World Bank, 2012 reported that the average daily generation of SW per capita in Sub- Saharan Africa is 0.65 kg, with a range of 0.09 to 3.0 kg. Sorting and separation of waste at source is not highly practiced (Strydom, 2018) and respondents indicated that their difficulties in waste sorting and separation is lack of available space for different waste type bins for storage. Waste collection in ward 27 is done when the communal bins are full, whereas in ward 25 is collected once a week. Both wards indicated that improper waste management practices lead to, amongst to other things, illegal dumping. Furthermore, the respondents stated that illegal dumping occurs because of ignorance, lack of knowledge and unavailable waste collection services. Niyobuhungiro and Schenck (2022), reported similar results. They recommended that the municipality should build recycling facilities, install disposal bins on hotspots for illegal dumping, and promote good SWM practices.
6.2.2 Forecasting of Municipal Solid Waste Generation.
The results of the study further showed that the multiple linear regression model that was used for forecasting waste generation rate in Polokwane Local Municipality yielded coefficient of determination (R2) of 0.88, with RMSE of 50690.2 ton/year and p<0.000.
The model was significant at p≤0.05 and was therefore used to forecast future SW
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generation rate from 2022 to 2026. The model showed that in the future the quantity of MSW is set to increase leading to the need for construction of a new landfill. These results will help SWM authorities to plan and make informed decisions on the quantity of waste that is likely to be generated in the future and subsequently, to decide on the possible need for a new landfill site. The significancy demonstrated by the independent variables regarding the dependent variable (Waste generation) in the study reveals similarity observed in the studies of Popli et al. (2021).
6.2.3 Integrating GIS and multi‑criteria decision analysis for landfill site selection.
The results for site selection for a new landfill estimated that roughly 67% of the area in Mankweng cluster is suitable for the construction of a disposal site. However, in future the land available might shrink due to rapid urban expansion. This study has demonstrated the effectiveness of the use of GIS-based MCDA in finding a suitable location for landfill site that correlates with other studies such as Chabok et al., 2020;
Makonyo and Msabi, 2021; Moon, 2020; Sener and Sener, 2020. This literature studies further show the similarity of the literature from various regions and the South African Regulations regarding criteria used of site selection of a landfill.