Satellite monitoring of current and historical development patterns in Big Sky, Montana : 1990-2005
Date
2008
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Montana State University - Bozeman, College of Agriculture
Abstract
The goal of this study was to map current and historical development patterns in Big Sky, Montana. Object-oriented classifications of a high-resolution Quickbird image and a fused Quickbird and LiDAR image were compared. Results demonstrated that object-oriented classification can be used to overcome the difficulty associated with pixel-based classification of high-resolution images through the addition of contextual metrics to the classification process. The fused classification resulted in decreased errors of commission and omission for each class, but the differences between the classifications were not statistically significant. The fused classification represented the shapes of land cover objects more precisely based on visual assessment. Temporal analysis of land cover patterns was accomplished successfully by using a generalized version of the fused classification to map historical development. Previous research on multitemporal mapping of multiresolution images has been lacking. Our research showed that the generalization of a high-resolution classification can be used as training data for a historical image. Normalized Difference Vegetation Index (NDVI) image differencing and boosted classification trees were used to identify and classify areas of change. This resulted in the successful identification of temporal changes in land cover due to Mountain Resort Development (MRD). Statistical pattern analysis revealed correlations between MRD and the variables distance-to-streams, distance-to-roads, slope, and aspect. Forest changes were found to be disproportionately located farther away from streams and on lower slopes. Grassland changes disproportionately occurred closer to steams, but overall grassland change was proportional to grassland land cover in 1990. Classification tree analysis indicated the variables distance-to-streams, distance-to-roads, slope, and aspect explained 87% of the variance for the change classes and might be related to amenity development. There was an increase in impervious surfaces and a decrease in both forests and grassland areas between the years 1990-2005. Loss of forest and grassland area can result in increased habitat fragmentation and can have negative consequences for ecosystems within the areas. Overall, this project successfully mapped both current and historical development patterns in Big Sky, Montana. This allowed for statistical pattern analysis of variables that have been shown to be correlated with MRD.