Project
Summary:
Methane (CH4), a potent greenhouse gas, is generated in landfills as waste decomposes. Landfills are recognized by the IPCC (Bogner et al. 2007) as being a major
source of global CH4 emissions. Inventories and modelling are widely used tools to predict future landfill gas emissions, however these models do not account
for local climate variations that could be observed in the future due to the effects of climate change (Kerr 2001).
Monitoring of landfill gas composition (CH4, CO2, O2, CO and H2S) has been carried out on gas wells over the last ten years at a residential development (6.5
ha) constructed on a closed municipal waste landfill in the North Island of New Zealand. The gas extraction network at the site comprises over 40 extraction
wells which are monitored weekly. There is also a dense monitoring network comprising over 1,230 monitoring points located in and below the landfill cap and
within the foundations of the buildings, which is monitored monthly.
Climate at the site is temperate, with warm, humid summers and mild, damp winters. Over the last ten years, a number of extreme meteorological events have
been observed (NIWA 2013a). The impacts of these events compared to typical meteorological conditions can be observed in changes in landfill gas emissions
and composition at the site.
This paper presents the correlations identified between landfill gas parameters and meteorological conditions over the last ten years. The implications
of this in terms of the possible influence of climate change on future landfill gas emissions has been considered for different climate scenarios (Randall
et al. 2007, MfE 2008) considering the potential changes in rainfall and temperatures. The findings provide useful information on how landfill gas emission
estimates and landfill gas collection systems can take account of the possible influence of climate change.
|
