ABSTRACT With the initiation of the Chief’s Conservation Agenda, watershed protection and restoration has become a focal point of Forest Service program activity. Watershed analysis is now a requirement for Forest Plan revisions. Forest change is a core watershed analysis parameter. This paper describes the utilization of North American Landscape Characterization (NALC) Landsat Multispectral Scanner (MSS) imagery to identify the location and trend in the proportion of vegetated land within the 5th level watersheds associated with the Southern Appalachian Planning Unit National Forests. The Southern Appalachian Planning Unit extends from Virginia to Alabama encompassing National Forests in 6 states. Landsat scenes acquired during the mid 1980’s and early 1990’s from 19 path/row scene locations were required to complete the project. To measure vegetation change the Normalized Difference Vegetation Index (NDVI) was calculated for each image. The breakpoint between vegetated and non-vegetated land was determined independently from the NDVI images for each date. Combinations of the vegetated and non-vegetated classes for the 2 dates were used to derive 4 vegetation change classes. Generalization routines were used to delete and recode to the surrounding class patches smaller than the minimum mapping unit. Supervised classification was used to identify areas of clouds and water on each date of imagery. The cloud and water images from the 2 dates were mosaicked with the vegetation data set to produce the final classified images. The classifications were exported to the ESRI Grid format and delivered to the planning team for integration into the watershed analysis. A Forest GIS specialist, under the direction of the Regional Remote Sensing Specialist, performed the work. The Forest Service advanced image processing workstation available under the IBM contract was used to conduct the project. The cost to provide the data to the planning team was $13,000 or approximately $.62 per thousand acres of watershed area. |