Mapping Hazardous River Ice from High Resolution Satellite Imagery

Abstract:

In interior Alaska, frozen river systems are important transportation corridors, due to the very limited road network. Long-time Alaskan residents report that winter travel conditions on Interior rivers have become more dangerous in recent memory. Field experience suggested that visual clues may provide experienced river travelers with clues of ice conditions. We explored the utility of airborne or satellite imagery as useful tools to map dangerous ice conditions on rivers in interior Alaska. Unsupervised classification of high-resolution satellite imagery was used to identify and map open water and degraded ice conditions on the Tanana River. An accuracy assessment indicated that snow, degraded ice, and open water were mapped with an overall accuracy of 73%, producer’s accuracies between (82 and 100%), and user’s accuracy ranging from (62 to 86%). Over 95% of the errors were caused by shadowing of trees or topographic features in the snow. The classification system performed well for a variety of satellite images and across different satellite platforms. With further development, these types of satellite remote sensing tools could prove to be very useful across a range of disciplines and industry in northern climates.