<p> The nearshore morphology of sand beaches in the Great Lakes usually consists of a ridge and runnel unit in the shallow, inner portion of the nearshore zone and one or more longshore bar and trough units in the deeper, outer portion. These two sets of features are morphologically and genetically different and exhibit spatial and temporal variations indicating the relative importance of environmental factors in controlling the form of each. </p> <p> Ridges and runnels form and evolve in response to a combination of the controlling factors of wave and water level variations. Ridge formation occurs in response to a rapid decrease in wave energy and lowering of the water level during the subsiding period of a storm. Ridges, with heights of 0.04-0.40 m, take 5-10 days to migrate 10-30 m across an inner nearshore terrace toward the shore. Ridge migration produces laminations dipping at 20°-30° toward the shore. Ridge attachment to the shore produces an accretional berm composed of laminations dipping at about 5° toward the lake. </p> <p> An annual cycle of erosion and deposition occurs in the inner nearshore and foreshore zones and is due to seasonal wave energy and water level variations. Erosion occurs in spring and summer because of rising water levels while the deposition of planar laminations dipping at less than 5° toward the lake is caused by lower water levels and higher energy waves in autumn. </p> <p> Based on the analysis of over 100 echo sounder profiles of the outer nearshore zone of 7 beaches, longshore bar and trough morphologic properties (maximum depth of bar formation, number of bars, and bar amplitudes), are controlled by three main environmental factors (wave energy or surf base, nearshore slope, and sediment size). Bars are present at depths of 3.5 m and at distances of 500 m from the shore, the number of bars ranges up to 6, and bar amplitudes range up to 2 m. Surf base ranges from 3-6 m, slopes from 0.009-0.02, and mean sediment size from 1.85 Ø - 3.30 Ø. There is a good correlation between the slope and sediment size. Temporal variation in bar morphology during the summer period of study is small or insignificant. </p> <p> Individual longshore bars probably only approach, rather than attain, equilibrium forms because of the temporal flucuations in the environmental controls of wave energy and water level. The geometrical trend in all longshore bar systems for the bar amplitude and spacing between bars to increase with increasing depth and distance from the shoreline, suggests a wave energy dissipation process which is somewhat analogous to dampened oscillation. </p> / Thesis / Master of Science (MSc)

<p> Chemical data from atmospheric precipitation in the Upper Great Lakes region were collected on a monthly basis by various organizations from late 1972 to late 1975. The data for pairs of chemical parameters are regarded as simultaneously recorded time series and are analyzed by spectral analysis to bring out periodic components present in both time series and also to reflect the correlation and phase difference between the pairs of time series.</p> <p> The precipitation data have four major bands of periodicities: (1) a yearly cycle representing high and low atmospheric loadings in the summer and winter respectively with regards to Fe, PART, SO4 and P; (2) a 6 monthly period reflecting the four seasons of the year and affecting Fe, PART, P and pH; (3) a 9 monthly period for the heavy metals (Cu, Ni, Cd, Pb and Zn); and (4) 2 to 5 cycles/month periodicities caused by atmospheric turbulence and affecting all the parameters.</p> <p> The mining-smelting industry at Sudbury has been identified as a major point source of atmospheric emissions of acid, sulfate and the heavy metals, with the exception of iron, This is evident in view of the facts that the spectral intensities at the major periodicities decrease away from the mining-smelting centre; the strikingly high correlation and practically inphase relationship between Cu and Ni, and the 9 monthly period for the heavy metals which is associated with the industry.</p> / Thesis / Bachelor of Science (BSc)

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Phragmites australis (Cav.) Trin. ex Steud., the invasive common reed, is a perennial grass with a cosmopolitan distribution. Unlike the native subspecies (Phragmites australis subsp. americanus) in North America, this invasive haplotype is an aggressive competitor and has firmly established itself throughout the Great Lakes basin by dominating wetlands and wet habitat, forcing out native plants and creating monocultures of little use to native fauna. Growing clonally and from seed, invasive Phragmites can quickly dominate wet areas throughout North America. It has also become a prominent feature in roadside habitats, where native plants are subject to increased disturbance under which invasive Phragmites will thrive competitively. In order to effectively manage this aggressive invader, we must be able to accurately map its distribution at multiple spatial scales, understand its invasion ecology, and determine efficacy of current removal efforts. In this thesis, I evaluated multiple remote sensing methods to determine the extent of invasive Phragmites. The basin-wide wetland mapping project based on satellite image data was a collaborative effort between U.S. and Canadian scientists to document the current and potential distribution of invasive Phragmites throughout 10-km of the shoreline of the Great Lakes, including all coastal marshes. To elucidate its distribution through road networks, I used provincial orthophotography databases to map changes in the distribution of Phragmites in road corridors between 2006 and 2010. Based on these data, I created a conceptual model to show the relationships among the main factors that govern the establishment of invasive Phragmites in roadsides within Ontario. These factors included habitat quality, habitat availability, and propagule dispersal. I also showed how unmanned aerial vehicles can be used with very high accuracy to map the distribution of very small stands of Phragmites at the beginning of an invasion, and to determine short-term changes in habitat availability in smaller wetlands. Using various remote sensing approaches, I was able to determine the efficacy of treatment programs implemented by provincial agencies on roadway corridors at the scale of the entire southwestern, southcentral and central regions of Ontario. This is the first quantitative evidence of invasive Phragmites removal along roads and one of the largest spatial and temporal time scales used to evaluate these processes. Finally, I synthesized the capabilities and limitations of these remote sensing methods to create an evaluative framework that outlines how to best map invasive Phragmites across varying landscapes. This research integrates geography and biology to create novel mapping techniques for invasive Phragmites and has furthered our understanding of this aggressive plant and how its invasion can be controlled. / Thesis / Doctor of Philosophy (PhD) / Invasive common reed, Phragmites australis subsp. australis, is one of the most aggressive and problematic invasive species in North America. This species rapidly expanded in the late 1900s and now occupies large patches of our critical wetland habitats as monocultures, especially in the northeastern states and the Great Lakes basin. My thesis presents new methods to identify where invasive common reed is present at a landscape level so that it can be targeted for large-scale control and removal. With colleagues in Michigan we created the first basin-wide map of invasive common reed for the Great Lakes region using satellite image data. Within Ontario, I used imagery from satellites and planes to determine the extent of invasive common reed along our road networks. At a site-specific scale, I used drones or unmanned aerial vehicles to map a protected wetland with high precision and accuracy. I used many of these approaches in combination to determine how effective current invasive common reed removal efforts are along roadway corridors. I compare all of these mapping processes and techniques to showcase the strengths and weaknesses of each approach and to help managers decide which approach is most suitable for their unique case. With all of these data, I have created new mapping techniques that can show the rapid spread of invasive common reed and how effective current management plans have been in combatting this aggressive invader.