Land-use and land-cover change, urban heat island phenomenon, and health implications: A remote sensing approach

Land-use and land-cover maps of Atlanta Metropolitan Area in Georgia were produced from Landsat MSS and TM images for 1973, 1979, 1983, 1987, 1992, and 1997, spanning a period of 25 years. Dramatic changes in land use and land cover have occurred, with loss of forest and cropland to urban use. In particular, low-density urban use, which includes largely residential use, has increased by over 119 percent between 1973 and 1997. These land-use and land-cover changes have drastically altered the land surface characteristics. An analysis of Landsot images revealed an increase in surface temperature and a decline in NDVI from 1973 to 1997. These changes have forced the development of a significant urban heat island effect at both the urban canopy and urban boundary layers as well as an increase in ground level ozone production to such an extent that Atlanta has violated EPA's ozone level standard in recent years. Using canonical correlation analysis, surface temperatures and NDVI, extracted from Landsat TM images, were found to correlate strongly with volatile organic compounds (VOC) and nitrogen oxides (NOx) emissions, the two ingredients that form ozone by reacting with sunlight, but only weakly with the rates of cardiovascular and chronic lower respiratory diseases, which also did not exhibit strong correlation with VOC and NOx emissions, possibly because other factors such as demographic and socio-economic may also be involved. Further research is therefore needed to understand the health geography and its relationship to land-use and land-cover change. This paper illustrates the usefulness of a remote sensing approach for this purpose.