Spatio-Temporal Modelling of the Change of Residential-Induced PM10 Pollution through Substitution of Coal with Natural Gas in Domestic Heating

Air pollution has been one of the most critical urban problems. Urban energy networks are among the major sources of air pollution, particularly in highly populated urban areas. Residential heating, which is the primary cause of particulate matter (PM) emissions, contributes to the problem through the use of low-quality fuels, such as coal. Natural gas, although a fossil fuel, is a modern, relatively clean, and more efficient alternative in residential energy use, which helps to reduce particulate matter emissions. Coal was widely used in residential heating in İzmir, Turkey, whereas natural gas is a relatively new alternative which started to be used domestically in 2006. Switching from coal and other highly polluting fossil fuels to natural gas in urban energy distribution network has contributed to the alleviation of air pollution in the city in the past decade. Spatiotemporal analyses of the PM10 concentrations, and their relation to the natural gas investments, have been conducted in geographical information systems (GIS). The spatial distribution of the change in PM10 levels has been modeled with ordinary kriging for the 2010–2011 and 2018–2019 winter seasons. Interpolated PM10 surfaces show that there is a significant decrease in the emissions throughout the city in the overall, while the highest levels of decrease are observed in the southern part of the city. Overlaying the interpolated PM10 surfaces and the natural gas pipeline investments enables the demonstration of the mutual relationship between the change in emission levels and the energy distribution network. Indeed, the spatial distribution of the pollution concentrations appears to be parallel to the natural gas investments. The pipeline investments were intensive during the 2010–2018 period in the southern districts when compared the rest of the city. The use of natural gas in residential heating contributed to the decrease in PM10 emissions