Changes in Geomorphic Processes in the Snake River Following Impoundment of Jackson Lake and Potential Changes Due to 1988 Fires in the Watershed

Abstract

Rivers are dynamic features of the landscape whose characteristics vary over time and space with changes in environmental controls. The Snake River in Grand Teton and Yellowstone National Parks has responded to the impoundment of Jackson Lake and subsequent changes in the operation of Jackson Dam. The 1988 fires in the Snake River watershed may also affect channel morphology. Whether a new system equilibrium might be attained and the extent to which the effects of past events might persist in the fluvial landscape, are two critical questions that need to be addressed for the Snake River. The stability of the Snake River, in turn, will affect the quantity and quality of riparian and aquatic habitats judged to be critical to fish and wildlife in the parks. Stream channel dynamics of the Snake River in Grand Teton National Park are also intimately tied to issues of floodplain delineation and management, the aesthetic value of rivers, and the quality of recreational float trips.