Thesis (M.S.)--Oregon State University, 1981. / Typescript (photocopy). Includes bibliographical references. Also available on the World Wide Web.

Thesis (M.S.)--Oregon State University, 1980. / Typescript (photocopy). Includes bibliographical references. Also available via the World Wide Web.

Thesis (Ph. D., Civil Engineering)--University of Idaho, July 2007. / Major professor: John M. Buffington. Includes bibliographical references. Also available online (PDF file) by subscription or by purchasing the individual file.

Approved for public release; distribution is unlimited / Observations of the temporal evolution of ripples are analyzed in terms of geometry, migration, crest orientation, and their predicted geometry by models using wave orbital velocities. Two weeks of bedform data were obtained in the surf zone during the RIPEX/SBE in April, 2001. Bed sediment consists of medium- to coarse-grained sand (D50=0.43mm). Models capture temporal trends in ripple geometry, but regression analyses show that they do not handle the range in forcing characteristics and geometries in the surf zone well. Transport models of bedload and total load formulated under uni-directional flows qualitatively capture the temporal evolution of observed transport by ripples, suggesting that under low to moderate forcing, bed load and suspended load occur mostly within the bed-following bottom boundary layer, andare measurable by ripple migration alone. Models predict large transport rates when flat beds were observed, so that at higher forcing ripples cannot be used to measure total sediment transport. Using a two-dimensional probability density function (PDF) of vector displacement peaks, a new ripple analysis model is proposed, incorporating a hierarchy of forcing complexity that includes such physical processes as directional spreading, axis rotation, orbital asymmetry, superimposed currents and infragravity wave velocities. The two-dimensional PDF's are compared with concurrent three-dimensional bed maps and are found to assist in describing ripple sizes, types, orientations, and migration velocities. / Lieutenant, United States Navy

Thesis (M.S. in Meteorology and Physical Oceanography)--Naval Postgraduate School, March 2003. / Thesis advisor(s): Timothy P. Stanton, Edward B. Thornton. Includes bibliographical references (p. 79-83). Also available online.

No description available.

Thesis (Ph. D.)--University of Washington, 1987. / Vita. Bibliography: leaves [101]-104.

Thesis (M.Phil.)--University of Waikato, 2006. / Includes bibliographical references (leaf 89)

A first-order approximation is made of the frequency and magnitude of bedload transport downstream of the Pelton-Round Butte Dam Complex, lower Deschutes River, Oregon with implications for salmonid spawning habitat. Field measurements of channel hydraulics, geometry, and particle size were combined with one-dimensional hydraulic and bedload transport models to determine the streamflow needed to move the channel bed material and to predict how much material would move once bedload transport was initiated. Inflows and outflows from the Dam Complex, and the predicted bedload carried by each, were compared to evaluate the effect of the Dam Complex on downstream discharge and bedload transport. Predicted critical discharges were equaled or exceeded very infrequently during the 72-year streamflow record. In addition, discharges capable of transporting bed material exceeded threshold conditions by very little. This has resulted in low predicted rates and amounts of bedload transport over the period of record. The Pelton-Round Butte Dam Complex was found to slightly increase the magnitude of flood peaks and associated predicted bedload transport for post-dam transport events exceeding threshold transport conditions. An exception to this pattern was the effect of the Dam Complex on the flood of December 1964, the second largest flood on record. This large flood occurred under unique circumstances -- while the reservoir of Round Butte Dam was filling for the first time. Since none of the transport events that occurred after the reservoir finished filling were affected by the Dam Complex in the same way as the 1964 event, the influence of the Complex on the 1964 flood is considered unique. The two largest floods on record (1964 and 1996), despite their relatively large sizes with respect to all other recorded flood events, did not cause major morphological changes to the lower Deschutes River. This observation, along with other independently derived information, supports the conclusion that the lower Deschutes is a very stable river. / Graduation date: 1998

Spatial and temporal variations in channel morphology, near-bed velocity, shear stress, bedload transport rate, pebble tracer movement, and bedload and bed material size distribution were measured in seven different channel patterns in two gravel-bed rivers in the Scottish Highlands (the Dubhaig and Feshie) and a proglacial stream in Norway (the Lyngsdalselva). The results showed that there were discernible links between the channel processes and changes which were consistent for all river types. 169 shear stress estimates from velocity profiles with changing discharge showed that Keller's (1971) velocity-reversal hypothesis holds true in different channel patterns of gravel-bed rivers and can be extended to include subunits of the pool/riffle cycle. At discharges near bankfull there is a decrease in the flow strength and amount of bedload movement from the poolhead down to the pooltail (and then riffle). On a broader scale 72 Helley-Smith bedload samples and the movement of over 3700 pebble tracers showed that the entrainment of different size fractions from heterogeneous bed material is inefficient and is overpredicted by the traditional bedload transport equations. Empirical analyses showed that when the armour is mobile/broken large and small particles have almost equal mobility as first proposed by Parker et al. (1982) and Andrews (1983). However for the majority of flow conditions the armour is static and entrainment is selective to a greater or lesser degree depending on the availability of appropriate-sized sediment at the surface and from bank erosion. The magnitude and direction of flow strength and bedload transport helps to explain the location and mode of channel development as revealed by repeated levelling and mapping. The accelerating convergent/decelerating divergent cells of flow alter the channel morphology in predictable ways. The positions of these cells can change with increasing discharge as the channel becomes generally, rather than locally, competent to move coarse sediment. The rates of bank erosion and volumetric scour and fill decreased from the active multi-braided system through to the stable straight channel type.