Monitoring the effects of air pollution on terrestrial ecosystems in Varanger (Norway) and Nikel-Pechenga (Russia) using remote sensing

During the period 1988–1993, NORUT Information Technology carried out a research project on the effects of air pollution on terrestrial ecosystems in the areas of Varanger (Norway) and Nikel-Pechenga (Russia). To maintain environmental surveillance over the extensive border area, NORUT used satellite remote sensing data in combination with ground truth measurements. During the project, we produced vegetation cover maps for four different years (1973, 1979, 1985, and 1988), a change detection image, and a vegetation change map. One of the major changes that can be observed on the vegetation cover maps is that the area with lichen-dominated vegetation decreased from 2783 km2 in 1973 to 538 km2 in 1988. Comparison of the vegetation cover maps and the change detection map with the total number of emissions of SO2 from industry shows a strong correlation between the decrease in lichen-dominated vegetation and the dramatic increase in emissions in the period 1973–1988. A correlation between the degradation of the vegetation and the SO2 concentration in the air has also been documented. The area of severe air pollution impacts increased from approximately 400 km2 in 1973 to more than 5000 km2 in 1988. This study shows that the critical loads/levels of air pollution have been exceeded for lichen-dominated vegetation cover types in the eastern parts of the study area. Finally, this study concludes that the use of optical remote sensing (Landsat MSS data) to map vegetation cover changes related to the impacts of air pollution was successful, with an overall classification accuracy of about 80%.