Inland lakes are important resources to humans, while the eutrophication effect caused by an overload of nutrients is a significant problem. This study focuses on utilizing the satellite remote sensing to monitor the water quality of Lake Simcoe, Ontario, Canada, which has been suffering from the overload of Total Phosphorus (TP) and therefore eutrophication for decades. The data employed in this study includes 22 cloud-free Landsat 5 TM images, as well as the nearly simultaneous in-situ data from 15 observation stations on the lake. Compared to the generally used model, an improved model is developed in this study to estimate the Secchi Disk Transparency (SDT), a parameter for water clarity measurements, using the TM images. Models based on different band combinations are compared to estimate the chlorophyll-a (chl-a) concentration. The results of these estimations are validated using the in-situ data by the linear regression analysis, and the accuracies are measured by the correlation coefficients R2. The results reveal that the improved SDT model provides higher prediction accuracies than the general model when applied to 68.2% (15 out of 22) of the images. The majority of the SDT predictions show high R2, whereas some of the estimated chl-a concentrations have weak relationships with the in-situ data. The possible reasons for this are the geo-location of stations, as well as the influences of chl-a and Dissolved Organic Carbon (DOC). The resultant concentration maps indicate that the eutrophic water is normally distributed at the near-shore areas and the northeastern part of Lake Simcoe. In addition, the southern Cook’s Bay has always been suffering from an extremely serious water quality problem even until now. Meanwhile, the water quality of the southwestern part of Lake Simcoe is much better than the other parts of this lake. The results also show that the water quality of Lake Simcoe was at its worst in August and September for the past 22 years while it was much better in the other sampling seasons. According to the trend of the monthly averaged SDT, on an overall scale, the SDT dropped from 1980 to 1982 and then kept relatively stable until the fall of 1992, followed by a gradual increase until 2000, and then stayed constant until the summer of 2008. The chl-a concentration reveals an inverse trend, i.e., the higher the chl-a concentration, the more turbid the water.

Inland lakes are important resources to humans, while the eutrophication effect caused by an overload of nutrients is a significant problem. This study focuses on utilizing the satellite remote sensing to monitor the water quality of Lake Simcoe, Ontario, Canada, which has been suffering from the overload of Total Phosphorus (TP) and therefore eutrophication for decades. The data employed in this study includes 22 cloud-free Landsat 5 TM images, as well as the nearly simultaneous in-situ data from 15 observation stations on the lake. Compared to the generally used model, an improved model is developed in this study to estimate the Secchi Disk Transparency (SDT), a parameter for water clarity measurements, using the TM images. Models based on different band combinations are compared to estimate the chlorophyll-a (chl-a) concentration. The results of these estimations are validated using the in-situ data by the linear regression analysis, and the accuracies are measured by the correlation coefficients R2. The results reveal that the improved SDT model provides higher prediction accuracies than the general model when applied to 68.2% (15 out of 22) of the images. The majority of the SDT predictions show high R2, whereas some of the estimated chl-a concentrations have weak relationships with the in-situ data. The possible reasons for this are the geo-location of stations, as well as the influences of chl-a and Dissolved Organic Carbon (DOC). The resultant concentration maps indicate that the eutrophic water is normally distributed at the near-shore areas and the northeastern part of Lake Simcoe. In addition, the southern Cook’s Bay has always been suffering from an extremely serious water quality problem even until now. Meanwhile, the water quality of the southwestern part of Lake Simcoe is much better than the other parts of this lake. The results also show that the water quality of Lake Simcoe was at its worst in August and September for the past 22 years while it was much better in the other sampling seasons. According to the trend of the monthly averaged SDT, on an overall scale, the SDT dropped from 1980 to 1982 and then kept relatively stable until the fall of 1992, followed by a gradual increase until 2000, and then stayed constant until the summer of 2008. The chl-a concentration reveals an inverse trend, i.e., the higher the chl-a concentration, the more turbid the water.

This thesis summarizes the efforts of two years of field investigation and water quality data analysis. With a focus on construction sites, background monitoring was carried out at two sites and data from a third, active site was also included for analysis. The water quality data was used to estimate event-based sediment yield from each location, and continuously-collected rainfall, water level and turbidity data was used to calibrate an event-based hydrologic model (SEDCAD). Based on the results of this research and the outputs of the calibrated model, an event-based sediment yield equation calibrated for Southern Ontario conditions is presented in conjunction with an IDF design tool. The IDF design tool can be used to effectively size and site construction-phase erosion and sediment controls before shovels break ground. The regulatory framework by which such controls are assessed is also discussed, and improvements to existing stormwater management guidelines are proposed.

Freshwater systems in Canada are affected by a multitude of environmental stressors, including cultural eutrophication, introduction of non‐native species, and climate change. Multiple stressors can interact in unpredictable ways and generate novel ecological scenarios, thus creating challenges for lake management. Lake Simcoe is an example of an aquatic system impacted by multiple stressors, facing management challenges of deteriorating water quality and coldwater fisheries. In order to better understand stressor interactions and pre‐disturbance lake conditions, a long‐term perspective is necessary. Therefore, this study used paleolimnological techniques to assess changes in the water quality of Lake Simcoe over the past ca. 200 years. Sedimentary diatom assemblages were analyzed in 210Pb‐dated cores from five sites across the lake. Diatom assemblages recorded several pronounced and synchronous shifts over the last ca. 200 years. Modest lake‐wide shifts in diatom community composition occurred in the late‐1800’s and early‐1900’s, suggesting that early cultural disturbances, such as land clearance and canal construction, had relatively minor impacts on Lake Simcoe. However, starting in the 1930’s, agricultural and urban development intensified, as indicated by substantial increases in eutrophic taxa. The most pronounced lake‐wide shift in diatom assemblages occurred in the mid‐to‐late 1900’s, the taxonomic nature and timing of which strongly suggest a response to regional climate warming. Moreover, diatom compositional trends at all sites were significantly correlated with instrumental records of regional temperature and lake ice the last ca. 100 years. An additional and marked lake‐wide shift in diatom assemblages occurred in the mid-1990’s, coinciding with the invasion of dreissenid mussels. The combination of stressors acting concurrently on Lake Simcoe, as well as the lake’s distinct water chemistry and size, make it challenging to reconstruct single limnological variables (such as, total phosphorus) in this system. Nevertheless, overall patterns of diatom compositional changes from the five sites revealed the largest shifts occurred in the post‐1950 sediments and that change in lake‐water total phosphorus concentrations played a minor role. Our results imply that substantial changes in climate have amplified the effects of multiple stressors in this complex system. / Thesis (Master, Biology) -- Queen's University, 2010-08-04 12:03:42.267

This study is made up of the geographical descriptions of Simcoe County in 1800, 1825, 1837 and 1866 with special reference to routes and transportation. A brief description of present conditions is included as a frame of reference for the other four periods. A concluding chapter summarizes the findings of the thesis. / Thesis / Master of Arts (MA)

Degradation of water quality, introduction of dreissenid mussels (notably <i>Dreissena polymorpha</i>) and depletion of oxygen concentrations in the hypolimnion in Lake Simcoe, Ontario prompted a study of phytoplankton primary production to inform efforts to improve the lake conditions. The characterization of algal production is critical since, as primary producers, their biomass is positively correlated with production at higher trophic levels in pelagic food webs and oxygen levels. This study was conducted from August 2010 to August 2011, including the winter season (Dec-Mar). Temporally, the lake displayed a unimodal pattern with late summer to fall production maxima. For all seasons considered, the pelagic daily areal primary production (P_int) was lower in the nearshore than offshore, consistent with the nearshore shunt hypothesis that mussels should be able to deplete phytoplankton more effectively in the nearshore. The sensitivity analysis revealed that chl a and the photosynthetic parameter P^B_max were the most influential variables for explaining such spatial differences. The size distribution of chl a and production varied where both netplankton (>20µm) and nanoplankton (2-20µm) were greatest in fall and picoplankton (<2µm) was highest in summer and early fall. A large chl a peak of nanoplankton was also found in late-winter (Mar) at offshore stations. The seasonal areal primary production (SAPP; May-Oct) and chl a:TP were significantly lower nearshore than offshore, consistent with grazing impacts from the large nearshore dreissenid mussel community. The lake as a whole is quite productive comparable to other large lakes with comparable total P concentrations and dreissenid mussel populations. The latter part of the study showed that the deep chlorophyll layer (DCL) was not as frequent as expected and was detected only 28% of time during late-spring to summer when the lake was thermally stratified (Aug-Sept 2010 and May-Aug 2011). The percent dissolved oxygen (%) did not show any indications of elevated primary production in the DCL although the production estimates suggested that there is a substantial (an average of 55%) amount of primary production occurring below thermocline when a DCL exists. Whether or not the DCL has potential to nourish the benthic filterers (dreissenids) and has ecological significance in the lake remains unclear. Overall, the factors that control phytoplankton primary production in Lake Simcoe seem to operate somewhat differently from other large lakes and further investigation is needed to elucidate them. The analysis of primary production and biomass has improved knowledge of non-summer production and can provide guidance to site-specific P and oxygen remediation.

Degradation of water quality, introduction of dreissenid mussels (notably <i>Dreissena polymorpha</i>) and depletion of oxygen concentrations in the hypolimnion in Lake Simcoe, Ontario prompted a study of phytoplankton primary production to inform efforts to improve the lake conditions. The characterization of algal production is critical since, as primary producers, their biomass is positively correlated with production at higher trophic levels in pelagic food webs and oxygen levels. This study was conducted from August 2010 to August 2011, including the winter season (Dec-Mar). Temporally, the lake displayed a unimodal pattern with late summer to fall production maxima. For all seasons considered, the pelagic daily areal primary production (P_int) was lower in the nearshore than offshore, consistent with the nearshore shunt hypothesis that mussels should be able to deplete phytoplankton more effectively in the nearshore. The sensitivity analysis revealed that chl a and the photosynthetic parameter P^B_max were the most influential variables for explaining such spatial differences. The size distribution of chl a and production varied where both netplankton (>20µm) and nanoplankton (2-20µm) were greatest in fall and picoplankton (<2µm) was highest in summer and early fall. A large chl a peak of nanoplankton was also found in late-winter (Mar) at offshore stations. The seasonal areal primary production (SAPP; May-Oct) and chl a:TP were significantly lower nearshore than offshore, consistent with grazing impacts from the large nearshore dreissenid mussel community. The lake as a whole is quite productive comparable to other large lakes with comparable total P concentrations and dreissenid mussel populations. The latter part of the study showed that the deep chlorophyll layer (DCL) was not as frequent as expected and was detected only 28% of time during late-spring to summer when the lake was thermally stratified (Aug-Sept 2010 and May-Aug 2011). The percent dissolved oxygen (%) did not show any indications of elevated primary production in the DCL although the production estimates suggested that there is a substantial (an average of 55%) amount of primary production occurring below thermocline when a DCL exists. Whether or not the DCL has potential to nourish the benthic filterers (dreissenids) and has ecological significance in the lake remains unclear. Overall, the factors that control phytoplankton primary production in Lake Simcoe seem to operate somewhat differently from other large lakes and further investigation is needed to elucidate them. The analysis of primary production and biomass has improved knowledge of non-summer production and can provide guidance to site-specific P and oxygen remediation.

No description available.

<p> Reflection and heating coefficients were measured during the 3 month summer season at Simcoe, southern Ontario. Contrasting agricultural surfaces and atmospheric conditions were used to analyse their effect on the reflection and heating coefficients. The results confirm the postulate of Montieth (1959a) that <alpha> is close to 0.25 for many vegetated surfaces. <beta> values were positive and there was a tendency for <beta> to approximate 0.22 for many of the vegetated surfaces. Finally it was shown that the radiation balance equation for Simcoe can be generalized into a linear function of solar radiation using the same constants that are applicable to many areas in the world. </p> / Thesis / Master of Arts (MA)

Le mémoire s'interroge sur les liens qui existent entre un texte et son illustration. Il prend pour assise un récit de voyage réalisé à la fin du XVIIIe siècle au Canada. Son auteure, artiste amateur, réalise en supplément au texte des esquisses qui complètent son travail pour renseigner sur la situation du Canada. Parmi ce qu'elle découvre en Amérique, la nature du continent retient la majeure partie de son attention. De 1791 à 1796, Elizabeth Posthuma Gwillim (1762-1850) accompagne son mari, le colonel John Graves Simcoe, assigné au poste de lieutenant-gouverneur du Haut-Canada (Ontario). Jeune femme de la classe supérieure britannique, Lady Simcoe assiste aux premières tentatives de colonisation dans une nature sauvage qui prend pour elle des allures grandioses. Dotée d'une curiosité insatiable, ravie de découvrir tout ce qui caracterise la nature de l'Amérique du Nord britannique, elle rédige de nombreuses lettres pour sa famille et ses proches qui, réunies, prennent la forme d'un récit de voyage détaillé. À ces lettres, elle ajoute également des dessins, paysages pour la plupart, qui servent de supplément à son texte. Ces dessins, esquisses de lieux admirables aux yeux de Lady Simcoe, sont conservés dans des carnets qui l'accompagnent dans la plupart de ses déplacements. Ces esquisses constituent le point de départ de cette étude, qui s'attarde essentiellement sur les relations entre un récit de voyage et ses illustrations. La période du voyage au Canada correspond à la fin de l'âge d'or de l'esthétique pittoresque en Angleterre. L'approche de la nature canadienne de l'artiste, marquée par la recherche d'un aspect sauvage, de l'irrégulier et de toute beauté naturelle apte à être transposée et codifiée dans un tableau d'art, est grandement influencée par les principes du goût pittoresque anglais de la fin du XVIIIe siècle. ______________________________________________________________________________ MOTS-CLÉS DE L’AUTEUR : Lady Simcoe, Récit de voyage, Pittoresque, Esquisse, Haut-Canada, Bas-Canada.