Meandering rivers are common on Earth and other planetary surfaces, yet the conditions necessary to maintain meandering channels unclear. As a consequence, self-maintaining with cutoffs have not been reproduced in laboratory. Such experimental needed explore mechanisms controlling migration rate, sinuosity, floodplain formation, planform morphodynamics test theories for wavelength bend propagation. Here we report an experiment which near-constant width was maintained during repeated cutoff...

Large woody debris is an integral component of forested, fluvial systems throughout the world, yet we know little about hydraulic thresholds for movement and transport logs. We developed theoretical models entrainment performed flume experiments to examine wood in streams. Both model indicate that log primarily a function piece angle relative flow direction, whether or not had rootwad, density log, diameter. Stability increased if pieces rootwads were rotated parallel flow. Although...

The influence of woody debris on channel morphology and aquatic habitat has been recognized for many years. Unlike sediment, however, little is known about how wood moves through river systems. We examined some dynamics transport in streams a series flume experiments observed three distinct regimes: uncongested, congested semi-congested. During uncongested transport, logs move without piece-to-piece interactions generally occupy less than 10 per cent the area. In together as single mass more...

Many dams have been removed in the recent decades U.S. for reasons including economics, safety, and ecological rehabilitation. More are under consideration removal; some of them medium to large-sized filled with millions cubic meters sediment. Reaching a decision remove dam deciding as how should be removed, however, usually not easy, especially dams. One major difficulty decision-making is lack understanding consequences release reservoir sediment downstream, or alternatively large expense...

This paper presents sample runs of the Dam Removal Express Assessment Models (DREAM) presented in companion paper, Cui et al. (2006): DREAM-1 for simulation sediment transport following removal a dam behind which reservoir deposit is composed primarily noncohesive sand and silt, DREAM-2 upper layer gravel. The primary purposes here are to validate some assumptions used model provide guidance as how accurately field data should be collected. Sample indicate that grain size distribution most...

The 14-m-tall Marmot Dam was removed during the summer of 2007, and cofferdam protecting working area breached a storm on October 19, allowing approximately 750,000 m3 reservoir deposit to be eroded freely released downstream Sandy River. Prior removal, sediment transport models were developed predict dynamics both gravel sand, providing key pieces information for stakeholders regulatory agencies select most appropriate dam removal alternative. A monitoring program implemented following that...

The influence of woody debris on channel morphology and aquatic habitat has been recognized for many years. Unlike sediment, however, little is known about how wood moves through river systems. We examined some dynamics transport in streams a series flume experiments observed three distinct regimes: uncongested, congested semi-congested. During uncongested transport, logs move without piece-to-piece interactions generally occupy less than 10 per cent the area. In together as single mass more...

Prediction of sediment transport dynamics following dam removal usually requires extensive field data, the collection which both resources and time. Certain management decisions regarding removal, however, may be required before allocated to provide sufficient data evaluate whether is a viable option. Here, we present case study demonstrate that some aspects characteristics can evaluated with very limited information. The in question involves J.C. Boyle, Copco, Iron Gate Dams on Klamath...