Physical and Environmental Geography Commons^™

Measuring The Morphologic Response Of Braided Rivers To Lateral Constriction, Victoria Barlow

Electronic Thesis and Dissertation Repository

The aim of this thesis is to understand the morphologic changes to a set of historically braided rivers that have been narrowed. Braided rivers from the agriculturally developed Canterbury Plains, New Zealand, were studied from a period prior to much development (mid-1900s) to the present. Narrowing of channels, decreased braiding intensity, and loss of braided planforms were determined based on aerial imagery, changing the geography of braiding along all rivers. Channel width and count were statistically correlated and show the predictability of braiding change based on narrowing. Reaches with initially wide channels require more narrowing to induce a simplification of …

Using Spatial Methods To Analyse Anthropogenic Predation Risk And Movement Ecology Of White-Tailed Deer (Odocoileus Virginianus), Rhiannon D. Kirton

Electronic Thesis and Dissertation Repository

Hunting has been used as a central tool by wildlife managers to maintain populations of game species, however, we still lack a good understanding of exactly how hunting influences deer biology. Technological advances in GPS data over the last two decades now enable us to perform more detailed analysis on the effects of human hunters on wildlife populations. This research explores the spatial ecology of hunters and White-tailed deer in the Cross Timbers ecoregion of Oklahoma. Using new statistical methodologies to analyse simultaneous GPS tracking data on deer and hunters to study their spatial interactions. The results show how new …

Bed Particle Dispersion And Scour In The San Juan (Pacheedaht) River, Meghan Sauro

Electronic Thesis and Dissertation Repository

As part of a larger river restoration project, bed particle dispersion was tracked at pool tailouts where salmon spawning is known to occur in the San Juan (Pacheedaht) River, B.C. Mobility and pathlengths of surface and sub-surface radio-tagged particles was characterized in three reaches over two deployment years in relation to annual channel change, flow magnitude, bar morphology and particle size. Surface particle mobility was high, with results from subsurface tracers indicating high spatial variation of scour at both the reach and local scale. Results also suggest scour can occur up to depths of 0.3m at some locations, even during …

Ground Warming Leads To Changes In Carbon Cycling In Northern Fen Peatlands: Implications For Carbon Storage, Ericka James

Electronic Thesis and Dissertation Repository

Northern peatlands store one third of the world’s soil carbon (C), as they remove more C from the atmosphere via photosynthesis than they release to the atmosphere through ecosystem respiration and methane (CH₄) production. Climate change threatens this function by stimulating C release from peatland stores as peat temperatures warm and soil moisture is reduced. Ground heating of +4 °C above ambient peat temperatures was initiated in a Sphagnum moss-dominated, nutrient poor fen and a Carex sedge-dominated, intermediate nutrient fen. Over one growing season, Carex fen heated plots had increases in photosynthesis (+23%), ecosystem respiration (+22%), and CH …

Airborne Observations Of Thermal Anisotropy From Urban Residential Neighbourhoods In Salt Lake City, Utah, Samantha J. Claessens

Electronic Thesis and Dissertation Repository

Urban surface temperatures are important variables in urban climatological processes. This thesis examines the directional variability of remotely sensed urban surface temperatures (thermal anisotropy or Λ) for three vegetated residential neighbourhoods in Salt Lake City, Utah, USA. Airborne thermal remote sensing using a thermal imager sampled the directional brightness temperature (DBT) at three times within a day for each site. Results indicate that temporal variability over a 20 – 30-minute flight was not negligible. Average DBT were then extracted from atmospherically corrected images and plotted on polar plots. For low density residential neighbourhoods Λ is increased with increasing tree-canopy coverage …

South Bend And Ridge Pine 2: Fraternal Twins, Gabryell Kurtzrock Belyea

Electronic Thesis and Dissertation Repository

The Ridge Pine 2 and South Bend sites lie within four kilometres of each other, both date to the late Middle Archaic period (ca. 5500-4500 before present), and both contain significant amounts of nonlocal chert. This exploitation of nonlocal chert occurred despite the close proximity of the Kettle Point chert outcrop to both sites. Notwithstanding their similarities, the two sites differ dramatically. From the raw material breakdown to projectile point types the two assemblages are quite different. These differences raise questions surrounding the chert procurement strategy employed by the groups at Ridge Pine 2 and South Bend. In order to …

Response Of Stream Biofilm Function To Pulsed Increases In Velocity And Nutrients: An Artificial Stream Study, Chris Lucas

Electronic Thesis and Dissertation Repository

Pulsed increases in flow within streams alter abiotic conditions such as nutrient concentrations and velocity which can influence the function of stream ecology, including biofilms. A 31-day artificial stream experiment at Thames River Experimental Stream Sciences (TRESS) Centre, London, Ontario, assessed the response of stream biofilm function (decomposition, primary production, community respiration) to individual and combined increases in velocity and phosphorus associated with a 48-hour hydrological pulse event. There was some evidence of an interactive subsidy effect of increased phosphorus and velocity on algal productivity. Decomposition increased as a result of increased phosphorus but there was no synergistic interaction of …

The Effect Of Sub-Facet Scale Geometry On Vertical Facet Temperatures In Urban Street Canyons, Rainer V.J. Hilland

Electronic Thesis and Dissertation Repository

Surface temperature plays a key role in many micro-scale urban processes. Walls comprise a significant percentage of the urban surface, yet are under-represented by many methods of thermal remote sensing and not considered in detail by micro-scale surface temperature mod- els. This thesis presents a novel method of mobile thermal observation performed in urban street canyons in London, ON that uses a thermal imager as well as a visual spectrum camera to provide dense spatial and temporal resolution of micro-scale wall temperature distributions. Images are manually classified by a series of nominal variables and the resulting data set discusses the …

Microclimate Variability Of Select Toronto Neighbourhoods Under Hot Summertime Conditions, Timothy Wiechers

Electronic Thesis and Dissertation Repository

Micrometeorological variability within cities has important implications for urban air and water quality, building energy consumption, and human health and thermal comfort. However, the monitoring of microscale climate is not routinely conducted. In most instances, primary meteorological observations are made under reproducible standard conditions (typically at an airport); but these open field observations tend to be unrepresentative of the intra-urban meteorological conditions.

This thesis used an alternative approach of conducting mobile traverse measurements using vehicle-mounted sensors to characterize the microclimates of Toronto, ON under hot, summertime weather conditions. Sampling occurred along two routes and incorporated sampling 8 intra-urban neighbourhoods with …

Morphological Bedload Transport In Gravel-Bed Braided Rivers, Sarah E. K. Peirce

Electronic Thesis and Dissertation Repository

Gravel-bed braided rivers, defined by their multi-thread planform and dynamic morphology, are commonly found in proglacial mountainous areas. With little cohesive sediment and a lack of stabilizing vegetation, the dynamic morphology of these rivers is fundamentally the result of bedload transport processes but our understanding of the fundamental relationships between channel form and bedload processes remains incomplete. For example, the area of the bed actively transporting bedload, known as the active width, is strongly linked to bedload transport rates but these relationships have not been investigated systematically in braided rivers. This research builds on previous research to investigate the relationships …

Wilket Creek: Urbanization, Geomorphology, Policy, And Design, Danielle Barr

Electronic Thesis and Dissertation Repository

The understanding of the morphology of an urbanized channel is currently limited to a ‘black box’ understanding in that the main driving force of morphological change is hydrologic. This study aimed to expand our understanding of urbanized channels by conducting a socio-geomorphological investigation; that is, the natural and policy-driven events and processes leading to the current channel form. A fluvial audit including historical analysis and fieldwork was conducted in Wilket Creek, a southern Ontario urbanized channel, along with a review of provincial and municipal policy and reports. Overall, it was concluded that the current morphology of Wilket Creek is the …

Environment And Health Perceptions In The Vicinty Of Surface Mining Concessions In The Upper West Region Of Ghana, Roger Antabe

Electronic Thesis and Dissertation Repository

The emergence of a gold mining industry and the influx of Artisanal Small Scale Mining following recent discoveries of gold deposits in Northern Ghana have posed new socio-cultural, economic, environment and health challenges for residents in a dry savannah zone that is already facing negative consequences of environmental change. Yet, knowledge of the impact of this emerging industry on the health of local population, and the extent to which it makes such a stressed environment more uninhabitable, has been lacking. In addition, studies elsewhere, mostly in the southern part of the country where mining predominates, have largely concentrated on assessing …

Dendroclimatic Studies Of White Spruce In The Yukon Territory, Canada, David S. Morimoto

Electronic Thesis and Dissertation Repository

An extensive network of 111 white spruce tree-ring chronologies (2983 trees) from treeline sites was developed across the Yukon Territory and adjacent areas of Alaska and British Columbia. Ring-width series from 73 chronologies with adequate signal strength back to 1800 were analysed using correlation and Principal Component analyses. Although 50 chronologies showed a strong common growth pattern over the 1900-1950 period (45.6% of the variance in PC1), PC1 over the 1950-2000 period included only 22 (27.1% of the variance). Correlation with temperature data from the central-north Yukon indicated that 1900-1950 PC1 chronologies showed significant positive relationships to summer (JJA) minimum …

Environment And Human Health In The Anthropocene: Interaction Between Natural And Social Systems In Coastal Tanzania, Frederick A. Armah

Electronic Thesis and Dissertation Repository

Coastal Tanzania, a region of historical and geopolitical importance in the western Indian Ocean, is a place where the problem of rapid environmental change is inextricably entwined with the challenges of development. In this region, although the fingerprint of the anthropocene has been discernible over the last century, there is paucity of research on how the population has interacted with the changing environment to generate disparities in perceptions of climate change and human health outcomes. The objectives of this thesis are four-fold: to assess barriers to climate change adaptation based on context (place), to explain group disparities in barriers to …

Land Use Interactions Drive Southwestern Ontario Stream Nutrient Concentrations, Renee L. Lazor

Electronic Thesis and Dissertation Repository

Human activities have transformed the landscape and altered natural habitats through intensive land uses including agriculture and urbanization. Identifying land use drivers of tributary nutrient concentrations and describing the magnitude and direction of their relationship are critical activities to improvement management of water quality in basins draining into the Great Lakes. The overarching goal of my thesis was to quantify the cumulative influence of spatial patterns in land use and land cover on variation of nutrient concentrations in tributaries of the Great Lakes. Biweekly water chemistry samples were collected in 29 streams located in southern Ontario between May and November, …

The Preferential Loss Of Small Geographically Isolated Wetlands On Prairie Landscapes, Jacqueline N. Serran

Electronic Thesis and Dissertation Repository

Reliable estimates of wetland loss require improved wetland inventories and effective monitoring programs. To improve upon current wetland inventories, a novel method for mapping wetlands using an automated object-based approach was developed for a regional watershed located in central Alberta. This approach used digital terrain objects derived from Light Detection and Ranging (LiDAR) data for which 130,157 wetlands were identified. Using this LiDAR derived wetland inventory, wetland loss estimates (% number and % area) were obtained by applying a wetland area vs. frequency function to the wetland inventory for the watershed. Using this power law, it was found that historically, …

A Sensor View Model To Investigate The Influence Of Tree Crowns On Effective Urban Thermal Anisotropy, Daniel R. Dyce

Electronic Thesis and Dissertation Repository

A sensor view model is modified to include trees using a gap probability approach to estimate foliage view factors and an energy budget model for leaf surface temperatures (SUM_VEG). The model is found to compare well with airborne thermal infrared (TIR) surface temperature measurements. SUM_VEG is used to investigate the influence of trees on thermal anisotropy for narrow field-of-view TIR remote sensors over treed residential urban surfaces. Tests on regularly-spaced arrays of cubes on March 28 and June 21 at latitudes of 47.6°N and 25.8°N show that trees both decrease and increase anisotropy as a function of …

Nitrate Sources And Lake Response In High Elevation Lakes, Uinta Mountains, Utah, Beth J. Hundey

Electronic Thesis and Dissertation Repository

Direct human activities in the Uinta Mountains, Utah, U.S.A., are limited to free-range grazing and recreation, but the larger-scale perturbations of climate warming and atmospheric deposition could also affect these remote sites. As few limnological measurements are available, it is difficult to discern whether changes in the high alpine lake ecosystems are occurring in this area. This study uses a range of paleolimnological and limnological techniques to: (1) identify the timing, nature, and causes of changes in primary production in high elevation Uinta Mountain lakes; (2) pinpoint the relative contributions of different sources of nitrate to these aquatic ecosystems; and …

"Being Stuck": Understanding The Health-Related And Everyday Lived Experiences Of Young Mothers In Rexdale, Ontario Through A Social Determinants Framework, Jaspreet Kaur

Electronic Thesis and Dissertation Repository

The purpose of this study was to gain an understanding of the ways the health-related and everyday lived experiences of young mothers are shaped by various social determinants, and in the context of their neighbourhood. Using a critical qualitative methodology, five mothers between the ages of 17 to 19 were interviewed from Rexdale, a neighbourhood in the City of Toronto characterized by a number of social risk factors(e.g. high rates of visible minorities, unemployment, and teen mothers). In-depth thematic analysis led to the emergence of four themes: 1) Living in Rexdale: Representations and realities; 2) Leaving Rexdale and wanting something …

The Periglacial Landscape Of Utopia Planitia; Geologic Evidence For Recent Climate Change On Mars., Mary C. Kerrigan

Electronic Thesis and Dissertation Repository

The northern plains of Utopia Planitia, Mars, hosts an abundance of potential periglacial landforms including scalloped depressions, gullies, and polygon networks. This research was undertaken to investigate the distribution and stratigraphy of scalloped depressions in Utopia Planitia and to reconstruct the past environment in which this periglacial landscape formed. To that end, a revised geologic map of the region has been produced. We define, for the first time, a new Periglacial Unit, the youngest geologic unit in Utopia Planitia. We have also developed a model for the formation and evolution of the periglacial landscape examined by assessing the use of …

Diatoms In Castor Lake (North-Central Washington, Usa) – Proxies Of Climate And Hydrologic Variation, Kelly D. Hollingshead

Electronic Thesis and Dissertation Repository

This research provides a high temporal resolution (1 sample / 2-3 years) record of hydrologic variation for the last 2,000 years using a lake sediment record from Castor Lake, a closed-basin system in Washington, USA. The core was dated using ¹³⁷Cs, ¹⁴C, and tephrochronology. Approximately 600 diatoms were identified and enumerated in 198 samples from a Castor Lake freeze core and Livingstone-piston core. A diatom-inference model for salinity was applied to reconstruct fossil diatom salinity. Diatom-inferred salinity for the last century tracked Palmer Drought Severity Index, indicating diatom community composition tracks effective moisture and can be used to …

Changes In The Hydrological Regime In The Upper Bow And Upper Athabasca Watersheds During The 20th Century, Heather A. Haines

Electronic Thesis and Dissertation Repository

This thesis examines 20^th century regime changes for the headwaters of the Bow (1911-2005) and Athabasca (1971-2005) Rivers. Changes in precipitation and temperature associated with the Pacific Decadal Oscillation dominate the Bow streamflow record. Higher snowfall, lower mean temperatures, and greater annual discharges occur during the “cool” PDO phase (1947-1976) with lower snowfall, higher mean temperatures, and lower annual discharges during the “warm” (1925-1946, 1977-2005) phases. Any long-term linear trends in the Bow record are masked by these multidecadal trends. The Athabasca record is too short to compare to the PDO but available data show patterns similar to the …