Thesis--Wisconsin. / Vita. Includes bibliographical references (leaves 275-294).

Thesis (M.S.)--Wisconsin. / Includes bibliographical references (leaves 54-55).

Oldenburg, Universiẗat, Diss., 2004.

Thesis (M.S.)--Oregon State University, 1985. / Typescript (photocopy). Includes bibliographical references (leaves 105-108). Also available on the World Wide Web.

Open channel confluences are common geographical structures in surface runoff. Most natural rivers originate from mountains and hills, flow into a main stream at confluences and finally head into the sea. Confluences are major sites for a main stream to obtain sediment and water from a tributary. Complex turbulence structures such as vortices, flow stagnation, secondary flow, flow re-circulation and water exchange both in vertical and lateral directions result in complicated sedimentation, erosion, mixing and contaminant transport at open channel confluences. The detailed study of flow dynamics and morphodynamics in confluences is of great significance to the urban flood control, scour of the river bed, design and maintenance of the channel and sediment and pollutants transport. This thesis describes a novel flume experiment on the sediment transport patterns in channel confluences as a function of different flow and geometry conditions. The initial equilibrium bed geometry was developed in a mobile bed confluence flume under four cases including two junction angles and two discharge ratios. The equilibrium bed was fixed for each case allowing for detailed flow velocimetry. The observed spatial patterns of turbulence statistics are evaluated with respect to the equilibrium bathymetry. Sediment were then fed instantaneously to the tributary channel at three different feeding sites in order to study the sediment deposition patterns. It was observed that although the sediment initiated at different feeding sites move along different paths through the confluence, all sediment tend to deposit at the face of the dune in the flow separation zone. This thesis also investigated how the deposition pattern would change versus time when feeding at the same site from the tributary channel. The time history of deposition pattern was also investigated for one of the cases. The sediment that initially deposit at the face of the dune eventually moved to the back of the dune and deposit around the post-confluence scour hole, demonstrating that over time the deposition pattern evolves to a state which is similar with the original bed morphology.

No description available.

Sediment bedload transport and bedform formation are considered for both steady and oscillatory flow of water. Some new theoretical results are quoted and experimental results are reported which tend to substantiate the theory. For steady flow, criteria based on Froude number and mean velocity are developed for predicting the types and dimensions of bedforms which occur under various flow conditions and different sediment properties. The flow depth is found to be an important variable linking Froude number with the mean velocity. For oscillatory flow, general agreement is found with the work of Mogridge and Kamphuis and the earlier work of Bagnold. The free surface wave parameters and the water flow depth are confirmed to be dominant factors in determining ripple characteristics. The experimental results give some confirmation of a new kinematic model proposed to explain sediment ripple behavior. / Applied Science, Faculty of / Civil Engineering, Department of / Unknown

No description available.

Thesis (Ph. D.)--College of William and Mary. / Typescript (photocopy). Vita. Includes bibliographical references (leaves 130-137).

Sediments negatively impact the quality of surface waters and are a significant source of contaminants, such as nutrients and pesticides in agricultural watersheds. Sediment fingerprinting is a relatively recent technique capable of determining the origin of suspended sediment. In this thesis, we investigated the sources of suspended sediments in a predominantly rural watershed in Atlantic Canada. Our first objective was to determine sediment source apportionment estimates by treating the watershed as a single catchment, and making the assumption that conditions affecting source production and transport, from the land to the stream, were uniform across the watershed. For the first objective, suspended sediments were collected at a single target location for sediment apportionment (main outlet) and used to represent sediment dynamics throughout the entire catchment. For the second objective, we examined not only the whole watershed but also sub-watersheds within it, to better understand processes affecting sediment dynamics. / October 2016