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

The aesthetic appeal of beaches has made coastal properties prime sites for development. However, this development has been mismanaged and is within the littoral active zone. Beaches retreat landwards as sea levels rise, but with current development trends, beaches are trapped in a coastal squeeze. Climate-change predictions include an increase in frequency and heightened intensity of storms, which can cause significant erosion. This study aimed to determine the ecological implications of sea-level rise and storms for beaches in KwaZulu-Natal (KZN), using geographic information systems (GIS) and beach sampling methods. The beaches were mapped in terms of physical and biological attributes. Spatial trends in these attributes showed that the coastline can be split into three – the northern, central and southern regions. Although 25 % of the coastline is protected by marine reserves, these are located in the Delagoa bioregion: 28 macrofauna species in the Natal bioregion are not protected. Storm impacts for beaches can be heterogeneous, depending on local coastal features, e.g., nearshore reef and sand dunes, and represented a temporary disturbance to macrofauna communities. A GIS-based coastal recession model was derived from Bruun’s rule, and applied for different scenarios of sea-level rise and coastal development. Coastal squeeze is concern, particularly in the southern region. Further, the 10-m elevation contour was not completely effective as a setback line, even for a low sea-level rise scenario. The coastal recession model was validated using data from a real event in KZN, where sea level rose temporarily by ~1.0 m. The model performed well, although the calibration possibly did not span a wide enough range of beach morphodynamic types, and under-predicted retreat for dissipative beaches. It was concluded that the Natal bioregion needs marine reserves, and that higher resolution spatial data are required for accurate beach modeling and the south coast railway line should be relocated proactively. Guidelines for sandy beach systematic conservation planning were outlined, and seated in a conceptual framework of managing beaches for resilience. Application of the proposed recommendations and frameworks could aid in determining a way forward in integrated coastal zone management for KZN, in the face of the uncertainties associated with climate change. / Thesis (M.Sc.)-University of KwaZulu-Natal, Westville, 2008.

Sandy beaches are a primary focus of recreational and other pressures from growing coastal populations, and are major natural and economic assets for national and international tourism, but have not received adequate research attention prior to this study. Although the limited ecological research to date indicates that the nearshore volumes of sandy beach systems may be as biologically productive as estuaries and wetlands, the management of sandy beaches has not been based on ecological or sustainability principles. In this study, the principles and goals of ecologically sustainable development (ESD) are applied in investigations designed to develop improved ecological and recreational management of metropolitan sandy beach ecosystems, whereby ecological functions are maintained simultaneously with recreational and related uses. The conventional view that sandy beaches are resilient to recreational use, and are more likely to be seriously impacted by other forms of human activity, seems to have precluded serious research investigation of questions such as: what are the responses of both beach biota and human users to environmental variables influencing the system; what are the simultaneous levels, distributions and diversity of beach biota in relation to levels, distributions and categories of beach users; and what ecological impacts are likely from human beach use on biota at points of interaction, temporally and spatially? From the first section of the project, it has been shown that our present understanding of the functions, processes and responses to human disturbances of sandy beach ecosystems is extremely poor, compared with that of rock platforms. New methodologies have been developed in the current study for experimental investigations into aspects of sandy beach ecology and recreational use which have never previously been considered. Relationships between environmental variables and categories of beach use have been quantified, and show promise for use in predictive modelling to guide management. Current approaches to the management of sandy beaches and beach recreation, as aspects of environmental and coastal resource management, were then critically examined. The structures, functions and decision-making procedures of the major spheres of government, and their management agencies, were evaluated and found to provide inherent obstacles to effective ecological and recreational management of ecosystems. Coastal resource and beach management by public agencies were assessed for Durban and Sydney. Comparative analysis has provided information that can be used to develop guidelines for integrated ecologial and recreational management of sandy beach systems. In a synthesis of all of the above findings, a new procedural model has been constructed, for sustainable ecological and recreational management of sandy beach systems. This model is proposed as a framework for future integrated coastal resource research and management. Note: Three published papers have been produced from the research in this study, and have been presented at conferences, being Sinclair-Hannocks and Keane (1992) at the Sydney Sister City Environmental Summit; Sinclair-Hannocks (1993) at the World Leisure and Recreation Association Congress; and Tsang and Sinclair-Hannocks (1993) at the Local Government and Environment Conference.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1993. / Abstract. Includes bibliographical references (leaves 52-56). Also available via the Internet.

Dissertation (Ph.D. in Physical Oceanography) Naval Postgraduate School, June 1997. / Dissertation supervisor, Edward B. Thornton. Includes bibliographical references (p. 149-152). Also available online.

Thesis (Ph.D.)--Aberdeen University, 2010. / Title from web page (viewed on Feb. 18, 2010). Includes bibliographical references.

Semi-enclosed coastal systems are of great importance bothenvironmentally and economically. ln recent years, increasedanthropogenic activities in these areas brought the need for integrated, ecosystem-scale management. This study proposes to estimate the assimilative capacity of a small fjord. This study had three main aims. The first one was to compare the pelagic properties observed in the 2000s to those observed at the same site in the 1970s, the second one was to design an accurate but simple, two dimensional dynamic model of a fjordic system for the prediction of chlorophyll and nutrient concentrations, and the third one was to propose a method for the estimation of the assimilative capacity of the fjord. This study was carried out on Loch Creran, a shallow fjord in the Scottish Highlands, in which a large sh farm was established in the 1980s. A sampling campaign was carried out 2003-2004 in order to collect time series of chlorophyll, dissolved inorganic nutrients and particulate organic matter concentrations; temperature, salinity, density and turbidity proles and microplankton and mesozooplankton diversity, abundance and biomass. Similar time series from the 1970s were gathered from the literature. The data from both decades were compared and showed significant changes in some physical, chemical and biological properties. The cessation of activity of an alginate production plant, changes inweather patterns and the introduction of aquaculture were identified as possible causes. A simple two-dimensional, three-box dynamic model of Loch Creran was designed. It has only three state variables (chlorophyll, nitrogen and phosphorus concentrations) and two crucial parameters (the exchange rate and the yield of chlorophyll from nutrients) as well as an optical-photosynthetic sub-model. The model was tested against observations for the years 1975 and 2003 and showed an overall good fit. The model was then run under different scenarios in order to estimate the assimilative capacity of Loch Creran for nitrogen and phosphorus and its carrying capacity for farmed salmon.

Coarse-grained beaches, such as pure gravel (PG), mixed sand-gravel (MSG) and composite (CSG) beaches, can be considered as one of the most resilient non-cohesive morpho-sedimentary coastal environments to energetic wave forcing (e.g., storms). The hydraulically-rough and permeable nature of gravel (D50 > 2 mm), together with the steep (reflective) beach face, provide efficient mechanisms of wave energy dissipation in the swash zone and provide a natural means of coastal defence. Despite their potential for shore protection very little is known about the response of these environments during high energetic wave conditions. Field measurements of sediment transport and hydrodynamics on coarse-grained beaches are difficult, because there are few instruments capable of taking direct measurements in an energetic swash zone in which large clasts are moving, and significant morphological changes occur within a short period of time. Remote sensing methods emerge in this context as the most appropriate solution for these types of field measurement. A new remote sensing method, based around a mid-range (~ 50 m) 2D laser-scanner was developed, which allows the collection of swash zone hydrodynamics (e.g., vertical and horizontal runup position, swash depth and velocity) and bed changes on wave-by-wave time scale. This instrument allowed the complete coverage of the swash zone on several coarse-grained beaches with a vertical accuracy of approximately 0.015 m and an average horizontal resolution of 0.07 m. The measurements performed with this new methodology are within the accuracy of traditional field techniques (e.g. video cameras, ultrasonic bed-level sensors or dGPS). Seven field experiments were performed between March 2012 and January 2014 on six different coarse-grained beaches (Loe Bar, Chesil, Slapton, Hayling Island, Westward Ho! and Seascale), with each deployment comprising the 2D laser-scanner together with complementary in-situ instrumentation (e.g., pressure transducer, ADV current meter). These datasets were used to explore the hydrodynamics and morphological response of the swash zone of these different environments under different energetic hydrodynamic regimes, ranging from positive, to zero, to negative freeboard regimes. With reference to the swash zone dynamics under storms with positive freeboard regimes (when runup was confined to the foreshore) it was found that extreme runup has an inverse relationship with the surf scaling parameter (=2Hs /gTptan2). The highest vertical runup excursions were found on the steepest beaches (PG beaches) and under long-period swell, while lower vertical runup excursions where linked to short-period waves and beaches with intermediate and dissipative surf zones, thus demonstrating that the contrasting degree of wave dissipation observed in the different types of surf zones is a key factor that control the extreme runup on coarse-grained beaches. Contrasting morphological responses were observed on the different coarse-grained beaches as a result of the distinct swash\surf zone hydrodynamics. PG beaches with narrow surf zone presented an asymmetric morphological response during the tide cycle (accretion during the rising and erosion during the falling tide) as a result of beach step adjustments to the prevailing hydrodynamics. On dissipative MSG and CSG beaches the morphological response was limited due to the very dissipative surf zone, while on an intermediate CSG beach significant erosion of the beach face and berm was observed during the entire tide cycle as a result of the absence of moderate surf zone wave dissipation and beach step dynamics. Fundamental processes related to the link between the beach step dynamics and the asymmetrical morphological response during the tidal cycle were for the first time measured under energetic wave conditions. During the rising tide the onshore shift of the breaking point triggers the onshore translation of the step and favors accretion (step deposit development), while during the falling tide the offshore translation of the wave breaking point triggers retreat of the step and favours backwash sediment transport (erosion of the step deposit). Under zero and negative freeboard storm regimes (when runup exceeds the crest of the barrier or foredune), field measurements complimented by numerical modelling (Xbeach-G) provide clear evidence that the presence of a bimodal wave spectrum enhances the vertical runup and can increase the likelihood of the occurrence of overtopping and overwash events over a gravel barrier. Most runup equations (e.g., Stockdon et al., 2006) used to predict the thresholds for storm impact regime (e.g., swash, overtopping and overwash) on barriers lack adequate characterisation of the full wave spectra; therefore, they may miss important aspects of the incident wave field, such as wave bimodality. XBeach-G allows a full characterization of the incident wave field and is capable of predicting the effect of wave spectra bimodality on the runup, thus demonstrating that is a more appropriate tool for predicting the storm impact regimes on gravel barriers. Regarding the definition of storm impact regimes on gravel barriers, it was found that wave period and wave spectra bimodality are key parameters that can affect significantly the definition of the thresholds for these different regimes. While short-period waves dissipate most of their energy before reaching the swash zone (due to breaking) and produce short runup excursions, long-period waves arrive at the swash zone with enhanced heights (due to shoaling) and break at the edge of the swash, thus promoting large runup excursions. When offshore wave spectrum presents a bimodal shape, the wave transformation on shallow waters favours the long period peak (even if the short-period peak is the most energetic offshore) and large runup excursions occur. XBeach-G simulations show that the morphological response of fine gravel barriers is distinct from coarse gravel barriers under similar overtopping conditions. While on coarser barriers overtopping regimes are expected to increase the crest elevation and narrow the barrier, on fine barriers sedimentation occurs on the back of the barrier and in the lower beach face. Such different sedimentation patterns are attributed to the different hydraulic conductivity of the different sediment sizes which control the amount of flow dissipation (due to infiltration) and, therefore, the capacity of the flow to transport sediment across and over the barrier crest. The present findings have significantly improved our conceptual understanding of the response of coarse-grained beaches during storms. A new field technique to measure swash dynamics in the field was developed during this thesis and has great potential to become widely used in a variety of coastal applications.

A study of beach profiles and sediment activity has been undertaken investigating natural beaches of inner coastal southwest British Columbia and published data on laboratory beaches. Two separate types of sediment activity are focused upon: longshore sediment, activity occurring on inner coast beaches and on- offshore sediment activity occurring on wave Hume constrained laboratory beaches. Field investigative work on twenty-five natural beaches has included review of past-field studies, profile surveys, sediment tracing experiments, investigation of surface and subsurface sediment, size distribution and structure, measurement of slopes and elevations of shoreline features, review of available wave climate data and wave hindcasting for the period of profile surveys. The work has shown that inner coastal beaches are predominantly shingle beaches or cobble armoured beaches with longshore sediment transport, occurring in a narrow upper foreshore zone under wave action at high tides. There is also evidence that coarse materials (gravels and cobbles) move selectively in an onshore direction and fine materials (silts and sands) move in an offshore direction. The sediment transport processes and beach characteristics identified are different from the summer/ winter beach process known to occur on open coasts. Laboratory beaches have been studied to identify the general response of a beach profile to waves. One problem in the study of beaches has been the lack of a readily measured variable to interrelate wave action and sediment movement. By studying laboratory beach profiles a variable representing on-offshore sediment, movement has been abstracted as an area swept out by differencing two profiles as a function of time. The variable has been investigated using laboratory beach data and correlation between it and wave parameters such as height, and period is evident. A dimensional analysis of on-offshore sediment transport is performed using the swept, area variable. / Applied Science, Faculty of / Civil Engineering, Department of / Graduate

A small body of saline rich water rests in the saturated zone between the foredune and the shoreline at certain beaches. This region is beneath the water table and the top of the fresher groundwater, known as the Upper Saline Plume (USP). The USP is significant because density driven flow and chemical fluxes between freshwater, rainwater, and seawater contribute to biogeochemical processes in the subterranean estuary (Duque et al. 2020). The occurrence of the USP has been observed along beaches that have a moderate to gentle slope, fine to medium grain size, and higher wave energy. The goal of this study was to determine if conditions for the presence of USP are consistent throughout different coastal beaches in southeast Florida while mapping the groundwater salinity across the beach. To identify the existence and delimit the boundary interface of the USP in the southeastern coast of Florida, multi–depth samplers were designed, built, and deployed along cross-shore transects at Jupiter and Gulfstream Beaches in Palm Beach County, FL. Groundwater samples were extracted along the transects to measure specific conductance. Although this study did not confirm the existence of the USP in South Florida beaches, an intermediate zone of water that is in-between the specific conductance ranges of relatively freshwater and relatively salty water was identified. Furthermore, the size of this intermediate zone was corresponded with beach slope, showing larger intermediate zones for steeper slopes and vice versa. Finally, temporal changes in the location and morphology of this intermediate zone were also identified in relation to a distinct disturbance event (Hurricane Isaias) which resulted in elevated ocean water levels. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2020. / FAU Electronic Theses and Dissertations Collection