In this activity, we will develop a detailed reactive transport model of hot-spot methane emission dynamics from active and closed municipal landfills that will include gas transport dynamics, microbial community response, and seasonal effects. Our model will build on an existing, fully-functional reactive transport model for variably saturated soils, subsurface heat, and gas transport, as well as thermodynamically-based models that predict reaction trajectories of multi-functional soil microbial communities under variable physical-chemical conditions. We expect the reaction network will respond strongly to changes in soil-atmosphere connectivity, soil moisture content, temperature, and methane gas dynamics.
We anticipate that the model results will lead to improve national estimates of methane emissions from landfill cover soils by incorporating seasonal climate variables, cover soil composition, and microbial community activities.