An Assessment of the Spatial Variability of Greenhouse Gas Emissions from Landfills: A GIS Based Statistical-Numerical Approach

Abstract

Emission of carbon dioxide and methane, two of the most important greenhouse gases, from landfills is a major concern. In this paper, a pseudo 3-D model, incorporating a 2-D geostatistical technique and a 1-D numerical model, was developed to study the spatial variability of the source strength of landfill gas. The 1-D model was used to represent advective, dispersive and reactive transport of landfill gas across the final cover of a landfill. The 1-D model was combined with a 2-D geostatistical technique to consider spatial distribution of landfill gas. The resulting pseudo 3-D model was developed within the ArcInfo GIS platform. Laboratory and field experiments were conducted to obtain data for calibration and verification of the model. The results indicated that the pseudo 3-D statistical-numerical model could be a useful tool to determine the source strength of landfill gas and to identify the location of hotspots beneath a landfill cover. A discussion of field applications and limitations of the model is also included.

Keywords: GIS applications, kriging, landfill gas, numerical modeling, source strength, spatial variations, surface emissions