Sensitivity Analysis of Population in the Generation of Hazardous and Non-Harzardous Wastes, and Gas from Dumpsites of Ogbomosoland in Nigeria


  • Samson O. Ojoawo
  • Oluwole A. Agbede
  • Abimbola Y. Sangodoyin


system dynamics, sensitivity analysis, population, non-hazardous wastes


This paper applies the principles of system dynamics modeling in studying the pattern of population changes and the corresponding non-hazardous wastes and gas being generated from the dumpsites of Ogbomosoland, Nigeria. The five (5) Local government Areas (LGAs) of Ogbomosoland were categorized as Urban (Ogbomoso North and Ogbomoso South) and Rural (Oriire, Ogo Oluwa and Suurulere) based on the size, population of residents, consumption pattern and socio-economic activities of the area. A sensitivity analysis of the simulated variables i.e the population, wastes and gas, was performed by employing the developed model results. Findings showed that the wastes and gas increased with the increased population in the 1000 years period. Also, gas production exceeds wastes generation rates for the rural LGAs in all cases. After a 25 years benchmark, when the simulated population of the urban and rural LGAs are respectively 303,411 and 344,735, the rates of waste generation are 3.33x106 and 6.22 x106 m 3 , while the corresponding rates of gas production is 2.44x103 and 6.47x103 m 3 in same order. The study concludes that wastes and gas generation from dumpsites are highly sensitive to population growth. It also concluded that the rate of gas generation is higher in organic wastes of the rural LGAs. The maximum population permissible in the model is 300,000 thus design of full-fledge landfills is recommended to replace the existing dumpsites in the study area.


USEPA, “Environmental Protection,” United States Environmental Protection Agency, Office of solid waste-home page,, 15th September 2012.

USEPA, “Why is solid waste management a challenge?” United States Environmental Protection Agency, Solid Waste and Emergency Response,, 10th February 2013.

SEPA, “What are the trends in wastes and their effects on human health and the environment?” Clark, R and Capponi, E eds 2005. United States Environmental Protection Agency, OECD in figures 2005: Statistics on the member countries. Organization for Economic Cooperation and Development (OECD) Observer, Paris, France, OECD, 2005

Omololu, O.O and Lawal, S.A, “Population growth and waste management in an African city,” Centre for Global Health Trinity College, Dublin. Technical Report, Irish Forum for Global Health (IFGH), August 2010

Inocencio, R, “World wastes 30% of all food,” CNN report,, February 9, 2013.

UDS, “What a waste: a global review of solid waste management,” Technical Report, Urban Development Seriesknowledge papers, July 2010.

Hansen J., “A slippery slope: How much global warming constitutes dangerous anthropogenic interference?” Climatic Change, vol. 68, pp 269-279, June 2005.

Hansen J., “Earth's Energy Imbalance: Confirmation and Implications,” Science, vol. 308, pp 1431-1435, September 2005.

Kunuawan, T., “Long-term Impact of Excessive Solid Waste Generation on the Environment,” IWA water wiki information resource and hub for the global water community, 2010.

UDS, “Waste generation,” Technical Report, Urban Development Series – Knowledge papers, May 2009.

Edward, B and Joel, L.M, “World Atlas,” 16th ed., USA, pp 21-35, 1978.

Chaerul, M., Tanaka, M and Shekdar K., “A system dynamics approach for hospital waste management,” Waste Management, vol. 28, pp 442-449, 2008.

Ulli-Beer, S., “Dynamic interactions between citizen choice and preferences and public initiatives- A system dynamics model of recycling dynamics in a typical Swiss locality,” In: Proceedings of the 2003 International Conference of the System Dynamics Society, New York City, USA, 20-24 July 2003, pp 25-34.

Dyson, B., Chang, N.B., “Forecasting municipal solid waste generation in a fast-growing urban region with system dynamics modeling,” Waste Management, vo l. 25, pp 669-679, 2005.

Sage, A.P, “Methodology of large scale systems,” 2 nd ed. London: Beverly Hill Sage Publications, 1980.

Beigl, P, Wassermann, G, Schnaider, F and Salhofer, S., “Forecasting municipal solid waste generation in major European cities,” In Pahl W, Schmidt, C.S and Jakeman, T. (Eds). iEMSs, 2004InternationalCongres, Germany,, February 27, 2012.

Dennison, C.J, Dodd, V.A., and Whelan, B., “A socio-economic based survey of household waste characteristics in the city of Dublin, Ireland,” Resources, Conservation and Recycling, vol. 17, pp 227-244, 1996.

Parizeau, K, Maclaren, V and Chanthy, L., “Waste characteristization as an element of waste management planning:

lessons learned from a study in Siem Reap, Cambodia,” Resources, Conservation and Recycling, vol. 49, pp 110-128, 2006.

Ehrig, H.J, “Prediction of landfill gas production from laboratory-scale tests,” Landfilling of waste: Biogas, E & FN SPON, pp 269-291, 1996 .

Ojoawo, S.O, “Management of Leachate Pollution from Dumpsites in Ogbomosoland, Nigeria,” U n p u b l i s h e d Ph.D Thesis, Faculty of Technology, University of Ibadan, pp. 113-147, 2009.

NPC, “Official gazette for 1991 population census,” National Population Commision, Nigeria, 1991.

NPC,“Official gazette for 2006 population census,” National Population Commision, Nigeria, 2006.

Cossu, R., Andreottola, G and Muntoni, A, “Modeling landfill gas production, Landfilling of waste: Biogas,” E & FN SPON, pp 237-268, 1996.




How to Cite

S. O. Ojoawo, O. A. Agbede, and A. Y. Sangodoyin, “Sensitivity Analysis of Population in the Generation of Hazardous and Non-Harzardous Wastes, and Gas from Dumpsites of Ogbomosoland in Nigeria”, Int. j. eng. technol. innov., vol. 3, no. 1, pp. 10–19, Jan. 2013.