Issues

Cover: The Green River in the Canyonlands region episodically narrowed by the creation of new floodplains, and permanent vegetated islands formed on top of mid-channel sandbars. These changes were first recognized by Will Graf in 1978 in a GSA Bulletin article (v. 89, p. 1491–1501, 2.0.CO;2">https://doi.org/10.1130/0016-7606(1978)89<1491:FATTSO>2.0.CO;2). Subsequent work demonstrates that narrowing began in the 1930s at the time the flow regime shifted and tamarisk began to invade the ecosystem, but the highest rate of narrowing began after 1985. At Hardscrabble Bottom, the rates and processes of floodplain formation were determined from sedimentologic analysis of a floodplain trench, analysis of air photos, and field surveys. See “Channel narrowing by inset floodplain formation of the lower Green River in the Canyonlands region, Utah” by Walker et al., p. 2333–2352.

Photo by: Todd Blythe.