Author(s): Renee Vandermause; Robert Ettema; Michael Harvey; Lyle Zevenbergen
Linked Author(s): Robert Ettema
Keywords: No Keywords
Abstract: A large hydroelectric project proposed for the Susitna River, a sub-Arctic river in Alaska, has created an opportunity to investigate the effects of river ice and freeze-related processes on the hydraulic erosion and geotechnical stability of river banks. One project impact on the river’s banks could occur by way of elevated stages and velocities of river flow during winter when the river is ice-covered and the banks are frozen. Exactly how this impact might affect the Susitna’s banks is unclear. To obtain early insights addressing this concern, a substantial study is underway to define the present state of the channel bed and banks along a reach of the Susitna extending downstream from the proposed dam site to the Susitna’s confluence with two major tributaries (the Talkeetna and Chulitna Rivers). This reach, termed the Middle River, is viewed as the reach likely to be most affected by the facility’s operation. Our paper describes the methodology for analysis and reports early findings from field data regarding the characteristics of the channel banks along the Middle River. We presently are analyzing the field data for indications of bank susceptibility to erosion or de-stabilization aggravated by the effects of ice and frigid weather, and the mechanisms causing these effects.