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.