115 research outputs found
Tracer study of mixing and transport in the Upper Hudson River with multiple dams
No full textAbstract In October 2001, ca. 0.2 mol of SF 6 was injected into the upper Hudson River, a modified natural channel with multiple dams, at Ft. Edward, NY. The tracer was monitored for 7 days as it moved ca. 50 km downriver. The longitudinal evolution of the tracer distribution was used to estimate 1-D advection (9.0 ± 0.2 km d -1 ) and dispersion (17.3 ± 4.0 m 2 s -1 ) along the river axis. Comparison of these results to tracer studies on channels without dams suggests that dams reduce longitudinal dispersion below the value expected in a natural channel with the same discharge. SF 6 loss through air-water gas exchange along the river and at two dams (10.7 m combined height) was estimated by observing decay in peak concentration. Losses at dams (approximately 50% per dam) were dominant. The estimated gas exchange at dams was compared to a simple model adapted from those available in the literature. Small amounts of tracer were trapped in a canal segment (ca. 5 km long) that parallels the river, where advection and dispersion were sharply reduced. Caplow, Schlosser, and Ho
- …
