Delineating drawdown lakes and Salix alaxensis in interior Alaska using Landsat TM and multitemporal SAR imagery

Abstract

This study evaluates the effectiveness of multitemporal Synthetic Aperture Radar (SAR) data and Landsat ETM+ imagery to delineate: 1) The locations of drawdown lakes within the Iditarod River drainage. 2) The locations of Salix alaxensis along the Innoko River. Both elements are related in that they constitute critical wildlife habitat, and their occurrence is largely due to seasonal flooding. Multitemporal, georeferenced Radarsat SAR imagery was used to classify lakes as either drawdown or non-drawdown. This technique yielded an overall classification accuracy of 78%, proving that multitemporal, georeferenced SAR is a good tool for delineating drawdown lakes. Landsat ETM+ imagery was used to develop three criteria (proximity to turbid water, broadleaf vegetation, and sandbars) to delineate S. alaxensis. Areas that met all three of the criteria had an estimated producer's accuracy of 4% for S. alaxensis, indicating that this technique is ineffective at delineating S. alaxensis.