Seasonal spatial variations of urban methane concentrations in a medium-sized city determined by easily measure variables

Abstract

The concentration of methane (CH4) in the urban atmosphere results from a balance between sources and sinks, as well as meteorological and topographical conditions that affect CH4 dispersion in the environment. Different geophysical, technical and demographic factors will determine the CH4 concentration in each city, and therefore further local research should be undertaken. The present study analyzes the relative contribution of sources on the atmospheric CH4 concentration in the urban core of Tandil city in Argentina. The temporal variation of meteorological parameters and the seasonal spatial variations of CH4 concentrations during a year were analyzed. In 9 of the sampling sites, the variables “distance from the wastewater treatment plant”, “homes connected to the natural gas network” and “distance from compressed natural gas stations” explained 29, 66 and 65% of the spatial variation of the atmospheric CH4 concentrations, respectively. The results highlight that the use of easily measured variables allows explaining a relatively high percentage of the spatial distribution of atmospheric CH4 concentration in the urban area. These demonstrate the need to improve the efficiency of the wastewater treatment systems and natural distribution and consumption to reduce the emissions of this potent greenhouse gas and its resulting impact on the environment.