INVESTIGATING THE USE OF GAGE DATA AND VEGETATION MAPPING TO DETERMINE THE RATE AND STYLE OF CHANNEL CHANGE ON THE WHEATON RIVER,YUKON TERRITORY, CANADA

Many rivers have been modified or heavily influenced by human interactions, which often causes a significant change to the naturally occurring river processes. Information regarding channel change in a natural setting is extremely valuable because it allows for a better understanding of natural processes. The Wheaton River (875 km²) is a tributary of the Yukon River that has experienced relatively little human impact or modification. The Wheaton is a sub-arctic river that is primarily snow-melt dominated but also contains a small glacial contribution. This study examines gage data (1996-2003) combined with channel and bar morphology to determine the style and rate of channel change on the Wheaton River. Bars were dated using tree cores and cross-sections. Preliminary results indicate that parts of the Wheaton River have experienced substantial erosion, deposition and channel avulsion during snow melt floods in the last decade (1999), however in other areas vegetation on bars adjacent to the channel is approximately 100 years in age. Potential explanations for the differences in channel stability along the river are bed and bank material characteristics, vegetation type and history, vegetation root strength, and deposition of woody debris, which influence the local effectiveness of flood events.