Image interpretation and classification of land cover change in Lake Clark and Kenai Fjords National Parks between 1954 and 2009

Burchiel, Mark; Maffitt, Bonnie; Robertson, Andy; Rokus, Dave; Stark, Kevin

This collaborative project was completed with cooperative involvement and expertise from the National Park Service and Saint Mary’s University of Minnesota’s GeoSpatial Services program. The goal of the project was to develop historical spatial datasets to assist the Southwest Alaska Network (SWAN) in identifying and classifying on-going landcover changes occurring in Lake Clark National Park and Preserve and Kenai Fjords National Park. Changes occurring in the natural environment have important consequences for ecosystem function and natural resource management. Historical aerial photography of many national lands was completed in Alaska during the 1950s. These images provide a point-in-time record of existing natural conditions. For this project, these older aerial photographs were converted to digital format then compared to remotely sensed imagery captured in the 1980s and 2000s as well as other thematic layers using a geographical information system (GIS). The effort to map landcover and landcover change over three time steps was completed using heads-up interpretation techniques by a skilled image analyst in a fully digital environment. A hybridized National Land Cover Dataset (NLCD) model was developed and used for classification of unique and regional features. Seven areas of interest, four in Lake Clark National Park and Preserve and three in Kenai Fjords National Park, were selected for study. The mapping project accomplished the objective to complete delineation and classification of land cover from three different time steps in over 170,000 acres of seven different areas of interest. This inventory data provides an important baseline dataset for future landcover change analysis, monitoring, and management activities. The resulting mapping products record landcover extent and classification for three different time periods spanning mid-1950 through 2009. Change classes were also delineated for each of the time periods mapped: 1950s-1980s, 1980s-2000s, and 1950s-2000s. Approximately 170,000 acres were mapped and classified using traditional image interpretation techniques. Challenges encountered were typical of any photo interpretation exercise and included: image resolution and quality, base map shifting as a result of orthorectification processes, limited availability of field-based collateral data for decision support, changes in image emulsion, diversity of the natural environment across project study areas, and the overall scope of potential landcover change types. Changes in landcover have important implications for ecological function and biodiversity. The information gathered for this project will benefit natural resource management efforts in LACL and KEFJ as conservation professionals seek to understand natural and anthropogenic forces affecting the nation’s national parks. Analysis of these data may assist park staff in identifying driving patterns of land cover change in the region such as vegetation cover, surface hydrology, fire regime, erosion and deposition, subsidence, uplift, and glacial extent.

Image interpretation and classification of land cover change in Lake Clark and Kenai Fjords National Parks between 1954 and 2009

Series

Collections