Thesis--Helsingfors. / Bibliography: p. [102]-106.

Thesis (M.Sc.)--College of William and Mary. / Vita. Includes bibliographical references.

No description available.

Approved for public release; distribution is unlimited / The coastal cliff top line recession has historically been used to calculate erosion along the Southern Monterey Bay. Digital photogrammetry is used in this work to produce Digital Terrain Models (DTM), representing the coastal cliff top line of 1984. This links the historical recession data sets with the LIDAR measurements of 1997 and 1998 and a 2003 cliff top line measured using Kinematic DGPS. Recession time series starting in the 1940's are produced for several locations. Least square linear fits of the recession data are computed for the periods 1940-84, 1940-98 and 1940-03. At Fort Ord and Sand City the resulting slopes show a persistent erosion trend of 1meter/year, unchanged in the last 19 years. The mean sea level (MSL) evolution is studied using historical San Francisco MSL data because of its high correlation with Monterey MSL. Higher MSL during El NinÌ o years, coincident with higher erosion rates show the correlation between erosion and MSL. In the long term, high-erosion El NinÌ o years combine with normal years averaging to a near constant erosion trend. For Phillips Petroleum and Beach Lab a significant decrease in the erosion rate is observed after sand mining stopped in Sand City. Digital Photogrammetry provides a high-quality representation of the shoreline topography, offering useful information to the warfighter in terms of detailed beach or landing zone characterizations. / Lieutenant Commander, Spanish Navy

The development of a new N-Line model, which provides a practical tool for simulating regional beach changes induced by short and long-term processes, is described in this thesis. The new N-Line model consists of four main modules that together describe the hydrodynamic and morphological responses. The four constituent modules have been integrated based on a wide range of research including the utility and function of commercial or freeware models. They are RCPWAVE wave module, time-averaged and depth-integrated current module, sediment transport module based on Bailard (1981) and contour change morphological module. Two different time-scales and two staggered grid systems for hydrodynamic and morphological simulations were adopted alternatively. For short-term 2D profile changes, new N-Line model applicability has been examined using data from the laboratory to the field. For ideal beaches, new N-Line can simulate an offshore storm bar generation or an onshore accretion due to high or low energy waves. For SUPERTANK large-scale flume data, the predicted profile matched the measured profile well, especially the bar height and position. For beach profile data from the Gold Coast, storm-induced variations of barred profiles were reasonably modelled. The new N-Line model compared well with other commonly used cross-shore models such as SBEACH and UNIBEST. A new schematisation for a non-monotonic profile and DUNED inclusion were introduced. Sensitivity tests on cross-shore sediment coefficient (Kq), smoothing parameter (??s) and water level fluctuations were performed. For long-term 3D beach changes, the new N-Line model applicability has been tested with various boundary conditions using idealized and real field data. Two periods, 17 and 16 months, of beach changes before and after a major bypass plant commenced operation in 2001 at Letitia Spit were simulated. The profile and shoreline changes were predicted reasonably well. Empirical model parameters were determined after a range of sensitivity and calibration testing. The new N-Line model showed its better performance compared to one-line models. It can handle various boundary conditions, especially bypass conditions. The N-Line model is not only capable of modelling planform variations but also cross-shore profile changes.

In 1996, Beach et al. first proposed the idea of mounting an echo-sounder on a Waverunner to measure nearshore beach profiles. This thesis discusses the Coastal Profiling System, an extension of the original work, which has been utilized to measure nearshore bathymetry at selected sites along the coasts of North Carolina, Oregon, and Washington. Position of the Coastal Profiling System is accurately measured five times per second using a differential global positioning system (DGPS), while depth below the hull is measured by an acoustic echo-sounder. Surveys can be conducted in waves up to 3 m and in depths of 1-15 m. The effects of waves, tides, and set-up are eliminated by the co-collection of position and depth data. In October 1997, extensive testing of the system took place at the SandyDuck '97 field experiment in Duck, NC. Nearshore bathymetric surveys were taken simultaneously by the Coastal Research Amphibious Buggy (CRAB) and the Coastal Profiling System (CPS). Comparison of the CPS with CRAB measurements interpolated to the same locations showed a mean bias of 4.6 cm too shallow in the vertical and standard deviations about the bias of 5.5 cm. The largest differences occur over the steeply sloping flanks of sand bars. The bias statistic, of central interest to these tests, is confused by the potential of boat tilt and by possible errors in the CRAB data itself. In July & August 1998, the system was tested as a tool for long-term coastal monitoring by the Southwest Washington Coastal Erosion Study in a regional morphology monitoring program (Ruggiero et al., 1997). A 2-3 km section in approximately the center of each of the four sub-cells of the Columbia River littoral cell, and an anomalous fifth site, was surveyed to map the morphology of each region. Alongshore-averaged profiles were decomposed into underlying AX[superscript m] profiles and deviations from this equilibrium profile. The mean of the exponents was close to 2/3 with m=0.70, but ranged between sites from 0.56 to 0.79. Shape parameters between 0.027 and 0.038 were estimated. Nearshore slopes (0-1 km cross-shore) were calculated from the exponential profile in the dissipative range with a minimum of 0.0067 and a maximum of 0.0089. However, no correlation was seen between the shape parameters and the 1 km nearshore slopes. An analysis of the deviations of the alongshore-averaged profiles from the equilibrium profile provided an objective method to determine sand bar positions from zero-down-crossings. Each site was characterized by a minimum of two sand bars in 2-6.5 m (NAVD 88) depths with heights of 0.2-2 m, lengths of 164-949 m and volumes of 48-534 m��/m. An additional bar in the swash zone between the +1 m elevation and 1 m depth contour was resolved in some cross-shore profiles. The crest of the bar largest in height was located at 3-4.5 NAVD 88 m at four of the five sites suggesting the profiles vary on similar cross-shore length scales amongst the sub-cells. A series of surveys in April, June, and October 1998 at the northern most site in Ocean City, WA demonstrated onshore bar migration and seaward accretion of the foreshore. This seasonal response was further quantified between August and October at Fort Canby. Three nearshore profiles surveyed by Willard Bascom et al. (1954) in the 1940s were reoccupied to compare the shape of the morphology 50 years ago to present. These profiles demonstrate accretion of approximately 2 m elevation gains in the nearshore and 26-165 m of shoreline change. Although the Coastal Profiling System is a highly accurate, mobile and efficient method to obtain nearshore profiles, several improvements have been suggested. Future modifications to the system should include an increase in the precision of the echo-sounder measurements, higher sampling rates, and improvement of the user interface. Additional components may include an onboard navigation system, a thermister to measure temperature and salinity, and a motion sensor to measure roll and pitch of the vehicle. / Graduation date: 1999

Thesis (M.S. in Meteorology and Physical Oceanography)--Naval Postgraduate School, March 2004. / Thesis advisor(s): Edward B. Thornton, James MacMahan. Includes bibliographical references (p. 37). Also available online.

Thesis (Ph. D.)--Ohio State University, 2003. / Title from first page of PDF file. Document formatted into pages; contains xiv, 142 p.; also includes graphics (some col.). Includes abstract and vita. Advisor: Ronxing Li, Dept.of Civil Engineering and Geodetic Science. Includes bibliographical references (p. 134-142).

Thesis (Ph. D.)--University of Hong Kong, 1973.

The importance of destructive processes in the morphology of carbonate shores has been recognized for many years. Field evidence of erosion in the form of shore platforms, reef flats and shoreline nips is widespread, especially in tropical and subtropical areas. However, it is obvious from a review of the literature that agreement is not complete on the dominant processes of erosion. [...]