USING LANDSAT IMAGERY TO EVALUATE LANDSCAPE-LEVEL IMPACTS OF NATURAL GAS FIELD DEVELOPMENT: TAZOVSKY PENNINSULA, RUSSIA, 1984-2007

Jesse Stevens Wallace, The University of Montana

Abstract

The Yamburg gas condensate field in northwestern Siberia sits atop the largest natural gas and petroleum basin in the world. Infrastructure related to the extraction and transport of natural gas is both geographically widespread, and has been shown to affect a much larger area than the immediate infrastructural footprint. Because field studies of the environmental impacts of development are often costly or unfeasible given the remoteness of these areas and access restrictions, the use of remote-sensing technologies is a valuable asset for assessing and quantifying disturbance over large areas. Freely available 30 meter resolution Landsat imagery from 1984 to 2007 was employed in this thesis to quantify the effects of natural gas infrastructure on the adjacent tundra using three methods: a landscape fragmentation analysis, mean and change in mean NDVI analyses, and a cross-tabulation analysis. These analyses show that the tundra has become increasingly fragmented during the study period, and that mean NDVI values in areas adjacent to development are lower than those calculated for undisturbed areas. As distance from the infrastructural footprint increases, differences in mean NDVI decrease, approaching undisturbed values at approximately 90 – 150 m. Additionally, analysis of changes in mean NDVI values over time indicate that new infrastructure development has a depressing effect on adjacent NDVI values, while areas that have been consistently developed show a vegetation recovery response evidenced by positive changes in NDVI values when compared to undisturbed areas. Cross-tabulation of the changes in NDVI values between analysis dates indicate that these changes can be attributed to the conversion of vegetated areas to bare ground or water in the case of new development, and conversion from bare ground or water to vegetation in areas that have been consistently developed.