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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Hydrodynamic Modelling of Lake Ontario

Hall, ERIN 21 October 2008 (has links)
The 2006 Clean Water Act requires each municipality to come up with science-based plans to protect the quality and quantity of their drinking water. A literature review concerning applicable processes in Lake Ontario along with previous modelling of the lake is presented. The three dimensional Estuary, Lake and Coastal Oceans Model (ELCOM) is used to model Lake Ontario on a 2×2km grid scale. The model is forced using meteorological data from the 2006 summer season, inflows and outflows. The lake-wide model is evaluated using field data from thermistor chains and ADCPs as well as historical water level data. Simulated and observed temperature profiles compared well. However, modelled temperature profiles were slightly cooler than observed. Current results were more variable than temperature profile results but compared better to observed data in the offshore regions. Simulating Lake Ontario water levels proved to be problematic because an accurate water balance is difficult to force with a large drainage basin. A 300×300m nearshore model of the eastern portion of Lake Ontario and the upper St. Lawrence River is also presented. The open boundary is forced using temperature data which is (A) varied with depth, (B) constant with depth and (C) spatially varied over the length of the open boundary and varied with depth. Both spatially varied and non-varied water level data forcing the open boundary is also compared. Spatially varied temperature and water level data is computed from the coarse grid lake-wide model. Lake-wide coarse grid model error appears to propagate through the open boundary negatively affecting nearshore modelled current when coupling the models. It was concluded that lake-wide model results should not be used to force the open boundary for the nearshore model. Nearshore model results using constant temperature with depth forcing files and non-spatially varied water level data agree well with observed temperature profiles, but further analysis is required for better confidence in the model's ability to properly reproduce currents at a 300×300m grid scale. / Thesis (Master, Civil Engineering) -- Queen's University, 2008-10-07 10:08:44.145
2

Lake Ontario Maritime Cultural Landscape

Ford, Benjamin L. 2009 August 1900 (has links)
The goal of the Lake Ontario Maritime Cultural Landscape project was to investigate the nature and distribution of archaeological sites along the northeast shoreline of Lake Ontario while examining the environmental, political, and cultural factors that influenced the position of these sites. The primary method of investigation was a combined archaeological and historical survey of the shoreline within seven 1-km square areas. The archaeological component of the survey covered both the terrestrial and submerged portions of the shore through marine remote sensing (side-scan sonar and magnetometer), diving surveys, pedestrian surveys, and informant interviews. A total of 39 sites and 51 isolated finds were identified or further analyzed as a result of this project. These sites ranged from the Middle Archaic period (ca. 5500-2500 B.C.) through the 19th century and included habitation, military, transportation, and recreational sites. Analysis of these findings was conducted at two scales: the individual survey area and Lake Ontario as a whole. By treating each survey area as a distinct landscape, it was possible to discuss how various cultures and groups used each space and to identify instances of both dynamism and continuity in the landscapes. Results of these analyses included the continuous occupation of several locations from pre-Contact times to the present, varying uses of the same environment in response to political and economic shifts, the formation of communities around transportation nodes, and recurring settlement patterns. The survey data was also combined to explore regional-scale trends that manifest themselves in the historical Lake Ontario littoral landscape including ephemeral landscapes, permeable boundaries, danger in the lake, and factors of change.
3

USING SATELLITE OBSERVATIONS TO ASSESS SUSPENDED SEDIMENT, ALGAL AND CYANOBACTERIA COMPOSITION IN LAKE ONTARIO

Rahman, FM Arifur 20 July 2021 (has links)
No description available.
4

High-resolution multi-temporal analysis of geomorphic change on the Sandy Pond Spit, eastern shore of Lake Ontario, NY

Kopp, Megan A January 2022 (has links)
Thesis advisor: Noah P. Snyder / Multi-temporal elevation (MTE) analysis is used to study topographic changes at specific intervals. Barrier-island complexes are often studied using this MTE analysis to quantify changes to the environment after hurricanes to understand how dynamic landscapes respond to different forcings. The Sandy Pond spit (SPS) is a north-south trending barrier island on the eastern shore of Lake Ontario, New York, which responds dynamically to fluctuations in water levels, ice cover, and storms. Prior research reconstructed the geomorphic history of the SPS from 1878-2013, determining that the most significant factor affecting decadal change is the lake-water elevation. In the summers of 2017 and 2019, anomalously high precipitation and lake levels resulted in increased erosion along the SPS, and flooding in neighboring communities. In this study I used shoreline position, foredune crest position and elevation and volume of deposition and erosion to determine the dominant force of geometric change on the SPS before, during and after the high water events in 2017 and 2019, using the study period 2001-2020. Lidar data and small uncrewed aerial system images are used to generate digital elevation models (DEMs) and DEMs of difference (DoDs) from surveys conducted in May 2001, July 2007, June 2011, October 2015, May 2018, September 2018, July 2020 and August 2020. Results indicated water level was the most significant factor altering the topography of the SPS. Large storm events although erosive, were not as destructive to the shore environment as the long duration elevated summer water levels. From 2001-2015 the shoreline advanced an average of 0.25 m/year. From 2015-2018 and 2018-2020 the shoreline retreated 0.62 m/year, and 3.27 m/year respectively. The foredune position and elevation altered due to erosion of the dune toe caused by wave action and shoreline retreat from 2015-2020 compared to 2001-2015. To study volumetric changes, the SPS was split into seven ecogeomorphic zones that characterize the barrier-spit system at large. From 2007-2015 net deposition was recorded at five of the seven zones when applying a 95% confidence interval. The zones recording erosion were characterized by high dune complexes with sparse vegetation to anchor sand. From 2015-2018 net erosion was recorded in all seven zones, indicating water level had a statistically significant effect on the rate and volume of geomorphic change to this ecosystem. / Thesis (MS) — Boston College, 2022. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Earth and Environmental Sciences.
5

The Calculation of Solar Radiation over Lake Ontario

Nunez, Manuel 09 1900 (has links)
<p> Simultaneous solar radiation and meteorological observations were taken from an instrumented tower located in southwestern Lake Ontario. During the four month period of this study (July-November, 1969) it was found that short-term fluxes of incoming global radiation could be predicted with a standard error which was better than 0.05 cal cm^-2min^-1 under cloudless conditions. Under cloudy conditions the lowest standard of prediction error (0.14 cal cm^-2min^-1) was obtained using a model which takes into account cloud type transmission. Under cloudless conditions the Fresnel curve underpredicts the albedos observed for low zenith angles and overpredicts when the zenith angle is high. This is mostly due to a backscatter effect estimated to be between 1.5 to 2% and to the albedo of diffuse radiation which was confirmed to be 6.5 to 7%.</p> / Thesis / Master of Science (MSc)
6

The Importance of Thermal Habitat Quality for Pumpkinseed (Centrarchidae: Lepomis gibbosus) in Small and Constructed Coastal Embayments Along the Northwest Shoreline of Lake Ontario

Murphy, Shidan 11 January 2012 (has links)
Along the Toronto shoreline, small coastal embayments (0.4 – 32 ha) are being constructed or modified to restore warmwater fish habitat. I describe how Lake Ontario (hereafter the Lake) alters the thermal regime of these small coastal embayments, how the altered thermal regimes affect growth and survival of age-0 warmwater fishes, and how the thermal habitat quality for such fishes can be improved by altering embayment design. During the warming period of the ice-free season, embayments warm faster than the Lake and so are cooled by exchanges with the Lake. Later in the year Lake exchange warms the rapidly cooling embayments, but the net effect of Lake-embayment exchange is cooling. The degree of cooling in Toronto’s small coastal embayments varies; many have temperatures near that of the Lake, and a few warm as much as local ponds. Age-0 pumpkinseed (Lepomis gibbosus) can fail to reach sufficient size to survive the winter in cooler embayments because their spawning is delayed and their growth is slowed. Most embayments along the Toronto shoreline are too cold to produce age-0 fish that can survive the winter, but all embayments are occupied by age >1 pumpkinseed, suggesting movement from warmer to cooler embayments. Using otolith microchemistry to identify natal embayments of fish, I confirm that age-0 and age-1 pumpkinseed, as well as age-0 largemouth bass (Micropterus salmoides) and age-0 yellow perch (Perca flavescens), exist in metapopulations. Embayment bathymetry is a poor predictor of temperature because almost all embayment flushing rates are very fast, usually 1-2 days. Warmer embayments are located in protected areas of Lake Ontario and receive waters that have already heated substantially. Cold embayments are located along the exposed shoreline of Lake Ontario. To protect embayments from cold lake waters, the cross-sectional area of embayment channels need to be reduced to 1-10% of their current size.
7

The Importance of Thermal Habitat Quality for Pumpkinseed (Centrarchidae: Lepomis gibbosus) in Small and Constructed Coastal Embayments Along the Northwest Shoreline of Lake Ontario

Murphy, Shidan 11 January 2012 (has links)
Along the Toronto shoreline, small coastal embayments (0.4 – 32 ha) are being constructed or modified to restore warmwater fish habitat. I describe how Lake Ontario (hereafter the Lake) alters the thermal regime of these small coastal embayments, how the altered thermal regimes affect growth and survival of age-0 warmwater fishes, and how the thermal habitat quality for such fishes can be improved by altering embayment design. During the warming period of the ice-free season, embayments warm faster than the Lake and so are cooled by exchanges with the Lake. Later in the year Lake exchange warms the rapidly cooling embayments, but the net effect of Lake-embayment exchange is cooling. The degree of cooling in Toronto’s small coastal embayments varies; many have temperatures near that of the Lake, and a few warm as much as local ponds. Age-0 pumpkinseed (Lepomis gibbosus) can fail to reach sufficient size to survive the winter in cooler embayments because their spawning is delayed and their growth is slowed. Most embayments along the Toronto shoreline are too cold to produce age-0 fish that can survive the winter, but all embayments are occupied by age >1 pumpkinseed, suggesting movement from warmer to cooler embayments. Using otolith microchemistry to identify natal embayments of fish, I confirm that age-0 and age-1 pumpkinseed, as well as age-0 largemouth bass (Micropterus salmoides) and age-0 yellow perch (Perca flavescens), exist in metapopulations. Embayment bathymetry is a poor predictor of temperature because almost all embayment flushing rates are very fast, usually 1-2 days. Warmer embayments are located in protected areas of Lake Ontario and receive waters that have already heated substantially. Cold embayments are located along the exposed shoreline of Lake Ontario. To protect embayments from cold lake waters, the cross-sectional area of embayment channels need to be reduced to 1-10% of their current size.
8

Ecological effects of Hemimysis anomala on the nearshore fish community of Lake Ontario

Yuille, Michael James 05 April 2012 (has links)
Species invasions are regarded as one of the most serious threats to biodiversity and native ecosystems and our ability to predict and quantify the impacts of invasive species has been an arduous task. Since the 1840s, the Laurentian Great Lakes have experienced an exponential increase in the number of identified invasive species. The most recent, Hemimysis anomala, is a littoral freshwater mysid native to the Ponto-Caspian region of Eastern Europe. They have been identified in all of the Great Lakes (except Lake Superior), the St. Lawrence River downstream to Québec City, and inland lakes in New York State and have the potential to destabilize energy flow in aquatic food webs. Using stable isotopes of carbon (13C) and nitrogen (15N), I evaluated nearshore food web structure at four sites along Lake Ontario’s north shore spanning a gradient of Hemimysis density to determine: 1) if dominant nearshore food web pathways change seasonally, and 2) whether fish exhibit a dietary shift towards consumption of Hemimysis. Also, the effects of Hemimysis consumption on the growth of yellow perch (Perca flavescens) were quantified using bioenergetics modeling and four predictive feeding scenarios simulating Hemimysis incorporation into yellow perch diets. My results suggest Hemimysis are being incorporated into diets of round gobies, alewife and small yellow perch, which has resulted in a trophic lengthening of the food web. As Hemimysis populations continue to establish and stabilize, fish may incorporate this species into their diets at a higher rate. Based on the bioenergetic modeling, the incorporation of Hemimysis into the diets of yellow perch will have a negative impact on their growth. These negative impacts on fish growth will likely be exacerbated when the limited seasonal availability of Hemimysis, patchy distribution and predator avoidance behaviours, are considered. These results have implications surrounding the sustainability of the Great Lakes fishery as Hemimysis will likely increase competition with young fish for food and fish consumption of this new invasive may lead to reduced fish growth. / Thesis (Master, Biology) -- Queen's University, 2012-04-03 23:04:18.612
9

Burlington Bar and Beach

Frazer, Lynn Deanne 04 1900 (has links)
This thesis examines a bayhead bar in the western end of the Lake Ontario Basin with the purpose of determining the dominant factors in the process-response model. From former field examination of the bar, and through the collection of deep drill cores, an attempt has been made to establish former processes which acted in the area of the present bar, Presently, field study, especially through the collecting of drill cores, sediment samples and wind data and by logging of wave data and longshore movement, has led to an attempt to establish the effect of present processes acting on the bar. / Thesis / Bachelor of Arts (BA)
10

THREE-DIMENSIONAL MODELLING OF LAKE ONTARIO HYDRODYNAMICS NEAR PORT HOPE AND IN THE UPPER ST LAWRENCE RIVER

Paturi, SHASTRI 18 July 2013 (has links)
The Ontario Clean Water Act (2006) mandated that eight and two municipal drinking water intakes in the Cataraqui Region Conservation Authority (CRCA) and the Ganaraska River Source Protection Agency (GRSPA) jurisdictions respectively, be protected from contaminants released into the surrounding waters through the delineation of Intake Protection Zones (IPZs). Toward these objectives, the Estuary and Lake Computer Model (ELCOM) was applied to simulate the hydrodynamics and contaminant transport in the eastern Lake Ontario and upper St. Lawrence River. Model hydrodynamics were comprehensively validated against field data collected during April-October, 2006. The flow was found to be predominantly wind induced in the southwestern lacustrine portion of the domain and hydraulically driven in the northeastern riverine portion with storm events resulting in river flow reversals. The modeled surface currents were applied to delineate IPZs surrounding the drinking water intakes. Passive tracers were simulated as surrogates for combined sewer outflows, tributary flows, municipal/wastewater and industrial discharges identified by CRCA as threats to drinking water intakes. Wind was found to be the most dominant forcing to transport contaminants, both in the Kingston Basin and the St. Lawrence River, whereas the St. Lawrence River outflow was found to influence the transport of contaminants along the river. The hydrodynamics and contaminant transport in the near-shore region of Lake Ontario, from Port Hope to Cobourg was also simulated using ELCOM and the results were comprehensively validated against field data collected during April-September, 2010. Upwelling and downwelling events caused by south-westerly and north-easterly winds were found to be the predominant hydrodynamic process. These events generated barotropic geostrophic alongshore currents or ‘coastal jets’ of ~20 cm s-1. Discharges from river plumes and sewage treatment plants were simulated as tracer releases. The tracer concentrations were primarily influenced by the close proximity of the intakes to the effluent release points, the volume and direction of the discharge from the intakes and the physical processes driving the flow dynamics. / Thesis (Ph.D, Civil Engineering) -- Queen's University, 2013-07-17 11:41:54.68

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