Geography Commons^™

Differentiating Fissure-Fed Lava Flow Types And Facies Using Radar And Lidar: An Example From The 2014–2015 Holuhraun Lava Flow-Field, Gavin Douglas Tolometti, Catherine D. Neish, Christopher W. Hamilton, Gordon R. Osinski, Antero Kukko, Joana R.C. Voigt

Earth Sciences Publications

Distinguishing between lava types and facies using remote sensing data is important for interpreting the emplacement history of lava flow-fields on Earth and other planetary bodies. Lava facies typically include a mixture of lava types and record the collective emplacement history of material preserved at a particular location. We seek to determine if lava facies in the 2014–2015 Holuhraun lava flow-field are discernible using radar roughness analysis. Furthermore, we also seek to distinguish between lava types using high resolution Light Detection and Ranging (LiDAR) data. We extracted circular polarization ratios (CPR) from the Uninhabited Aerial Vehicle Synthetic Aperture Radar and …

The Physical Properties Of Volcanic And Impact Melt, Gavin Douglas Tolometti

Electronic Thesis and Dissertation Repository

The emplacement mechanisms of lunar impact melt flows, that form from hypervelocity impact events, have been a subject of debate in the lunar science community, because of their unique physical properties that separate them from other geologic features. Understanding how lunar impact melt flows were emplaced on the surface of the Moon will not only grant us new information about the flow dynamics of impact melt but provide insight into the production and distribution of impact melt and how it built and modified the surfaces of planetary surfaces.

Lunar impact melt flows exhibit surface roughness textures and morphologies that are …

Building Climate Resilient Communities: Living Within The Earth’S Carrying Capacity, Gordon Mcbean, Paul Kovacs, James Voogt, Greg Kopp, Sophie Guilbault

Geography & Environment Publications

This Knowledge Synthesis examines how Canadian communities can proactively advance climate resilience to effectively reduce the risk from climate change impacts.

Our synthesis reveals that some communities have prepared high level adaptation plans, but very few have a detailed implementation strategy with established funding frameworks. Most actions to build community resilience in Canada are unplanned and take place in recovery following an extreme loss event. Indigenous communities are at the forefront of climate change adaptation in Canada. Self-determination and adaptive capacity building through community-led risk assessments, planning, and disaster recovery organizations, while addressing the broader context of reconciliation gaps and …

Agriculture, Food Security And Climate Change Panel, Andrew Walsh

Africa-Western Collaborations Day 2020

8 graduate student/recent graduate presentations on varying topics of agriculture, food security and climate change. Moderated by Dr. Andrew Walsh. Reporting of panel done by current GHS students of the 2021 class. Abstracts can be found under "Africa-Western Collaborations Day 2020 Abstracts". Presenters as follows:

Daniel Amoak, "Coping Strategies of Agrarian Households"

Eunice Annan-Aggrey, "The Conundrum of Vanishing 'Gold' in the African Savannah"

Evans Batung, "Credit Access and Perceived Climate Change Resilience of Smallholder Farmers in semi-arid Northern Ghana"

Chengyu (Jennifer) Guo et al., "Production of Flavoured Fiti Probiotic Yoghurt for the London Community"

Daniel Kpienbaareh et al., "Estimating Yield …

Understanding The Support For Municipal Green Bin Programs, Oluwatomilola Ladele

Electronic Thesis and Dissertation Repository

As food waste increases globally, many cities have implemented curbside collection of food waste (aka green bin programs) to divert food waste from landfills. However, not all municipalities in Ontario have green bin programs. A factor responsible for the adoption of green bin programs is the community support for the program. The study results are based on 407 completed surveys from randomly selected households in London, Ontario (a municipality without a green bin program) and Kitchener-Waterloo, Ontario (a municipality with a green bin program). Surveys were used to collect data to understand: i) the predictors of household green bin support …

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 …

Comparative Assessment Of Downscaling Methods And Application Towards Analysis Of Climate Change Impact On Urban Regions, Markus Eichenbaum

Electronic Thesis and Dissertation Repository

Global climate models (GCM) are sophisticated numerical models used to make long term climate projections. However, the resolution of their output is too coarse for climate change related local impact studies on urban regional scales. Downscaling efforts are taken to address this and increase GCM projection resolution. Physical Scaling (SP) downscaling methodology attempts to incorporate the physical basis of dynamical downscaling efforts with the computational efficiency of statistical methods. In this study, North American Regional Reanalysis surface skin temperature and precipitation data for a 1°x1° region centered on Houston, TX are downscaled to a resolution of 500m via SP and …

Short Communication: Challenges And Applications Of Structure-From-Motion Photogrammetry In A Physical Model Of A Braided River, Peter Ashmore, Pauline Leduc, Sarah Peirce

Geography & Environment Publications

For extending the applications of structure-from-motion (SfM) photogrammetry in river flumes, we present the main challenges and methods used to collect a large dataset ( > 1000 digital elevation models, DEMs) of high-quality topographic data using close-range SfM photogrammetry. Automatic target detection, batch processing, and considerations for image quality were fundamental to the successful implementation of the SfM technique on such a large dataset, which was used primarily for capturing details of gravel-bed braided river morphodynamics and sedimentology. While the applications of close-range SfM photogrammetry are numerous, we include sample results from DEM differencing, which was used to quantify morphology change …

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 …

Rates Of Planimetric Change In A Proglacial Gravel-Bed Braided River: Field Measurement And Physical Modeling, Lara Middleton, Peter Ashmore, Pauline Leduc, Darren Sjogren

Geography & Environment Publications

Planimetric change was measured on daily hydrographs over two meltwater seasons using time-lapse images of the proglacial, gravel, braided, Sunwapta River, Canada. Significant planimetric change occurred on 10-15 days per year. Area of planimetric change correlated with peak and total daily meltwater hydrograph discharge. A clear threshold discharge can be identified below which no planform activity occurs, an intermediate range over which change occurs conditionally, and a peak flow range at which significant change always occurs. Field conditions were reproduced in a physical model in a laboratory flume. Photogrammetric DEMs of bed morphology and measurements of bedload output were made …

Evolution Of Grain Size Distributions And Bed Mobility During Hydrographs In Gravel-Bed Braided Rivers, Sarah Peirce, Peter Ashmore, Pauline Leduc

Geography & Environment Publications

Evolution of bed material mobility and bedload grain size distributions under a range of discharges is rarely observed in braiding in gravel-bed rivers. Yet, the changing of bedload grain size distributions with discharge is expected to be different from laterally stable, threshold, channels on which most gravel bedload theory and observation are based. Here, simultaneous observations of flow, bedload transport rate, and morphological change were made in a physical model of a gravel-bed braided river to document the evolution of grain size distributions and bed mobility over three experimental event hydrographs. Bedload transport rate and grain size distributions were measured …

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 …

The Variability In The Morphological Active Width: Results From Physical Models Of Gravel‐Bed Braided Rivers, Sarah Peirce, Pauline Leduc, Peter Ashmore

Geography & Environment Publications

The morphological active width, defined as the lateral extent of bed-material displacement over time, is a fundamental parameter in multi-threaded gravel-bed rivers, linking complex channel dynamics to bedload transport. Here, results are presented from 5 constant discharge experiments, and three event hydrographs, covering a range of flow strengths and channel configurations for which morphological change, bedload transport rates, and stream power were measured in a physical model. Changes in channel morphology were determined via differencing of photogrammetrically-derived digital elevation models (DEMs) of the model surface generated at regular intervals over the course of ~115 hours of experimental runs. Independent measures …

Expanding The "Active Layer", Peter Ashmore, Sarah Peirce, Pauline Leduc

Geography & Environment Publications

Church and Haschenburger (2017) make helpful distinctions around the issue of defining the active layer, with which we agree. We propose expanding discussion and definition of the ”active layer” in fluvial bedload transport to include the concept of the “morphological active layer”. This is particularly applicable to laterally unstable rivers (such as braided rivers) in which progressive morphological change over short time periods is the process by which much of the bedload transport occurs. The morphological active layer is also distinguished by variable lateral and longitudinal extent continuity over a range of flows and transport intensity. We suggest that the …

Quality Assessment Of The Canadian Openstreetmap Road Networks, Hongyu Zhang

Electronic Thesis and Dissertation Repository

Volunteered geographic information (VGI) has been applied in many fields such as participatory planning, humanitarian relief and crisis management because of its cost-effectiveness. However, coverage and accuracy of VGI cannot be guaranteed. OpenStreetMap (OSM) is a popular VGI platform that allows users to create or edit maps using GPS-enabled devices or aerial imageries. The issue of geospatial data quality in OSM has become a trending research topic because of the large size of the dataset and the multiple channels of data access. The objective of this study is to examine the overall reliability of the Canadian OSM data. A systematic …

Accuracy Evaluation Of The Canadian Openstreetmap Road Networks, Hongyu Zhang, Jacek Malczewski

Geography & Environment Publications

Volunteered geographic information (VGI) has been applied in many fields such as participatory planning, humanitarian relief and crisis management. One of the reasons for popularity of VGI is its cost-effectiveness. However, the coverage and accuracy of VGI cannot be guaranteed. The issue of geospatial data quality in the OpenStreetMap (OSM) project has become a trending research topic because of the large size of the dataset and the multiple channels of data access. This paper provides details on a national study of the Canadian OSM street network data for the assessment ofcompleteness, positional accuracy, attribute accuracy, semantic accuracy and lineage. The …

Morpho-Sedimentary Characteristics Of Proximal Gravel Braided River Deposits In A Froude-Scaled Physical Model, Peter Ashmore, Tobias Gardner, Pauline Leduc

Geography & Environment Publications

A Froude‐scaled physical model of a proximal gravel‐bed braided river was used to connect the river morphological characteristics, and sedimentary processes and forms, to deposit geometry. High resolution continuous three‐dimensional topographic data were acquired from sequential photogrammetric digital elevation models paired with grain‐size surface maps derived from image analysis of textural properties of the surface. From these data, the full three‐dimensional development of the braided river deposit and grain‐size sorting patterns was compiled over an experimental time period of 41 h during which the model river reworked a large portion of the braided channel. The minimum surface of the deposit …

Uncertainty Analysis Of The Performance Of A System Of Best Management Practices For Achieving Phosphorus Load Reduction To Surface Waters, Jason D.M. Igras

Electronic Thesis and Dissertation Repository

The repeated occurrence of Lake Erie’s harmful algal blooms suggests an inadequate phosphorus management system that results in excessive loads to the lake. In response, Canadian and United States’ governments have issued a new management objective, a 40% reduction in total and dissolved reactive phosphorus loads relative to 2008. To provide scientific evidence to guide managers toward achieving their management objective, we used the International Organization of Standardization (ISO) 31010 Bowtie Risk Analysis Tool to analyze the performance of the phosphorus management system. The effectiveness of agricultural best management practices (BMPs) and their adoption were combined into a Bayesian belief …

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, …

Environmental Health Effects Of Multiple Exposures: Systemic Risks And The Detroit River International Crossing Study, Tor H. Oiamo

Electronic Thesis and Dissertation Repository

This thesis examines cumulative exposures to traffic noise and outdoor air pollution on environmental and health related quality of life in Windsor, Ontario, and provides a critical analysis of the environmental assessment process for the Detroit River International Crossing (DRIC) Study. The research utilizes a systemic risk framework to understand environmental health and stress effects of cumulative exposures. The significance of this research is based on a relative absence of literature on the systemic health risks of cumulative exposures and the need to elucidate environmental annoyance as a health outcome for risk assessment. The objectives of the research were to …

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 …

Geography, News Media Discourse, And Water Management: A Case Study Of The Devils Lake Outlet, Daniel J. Bednar

Electronic Thesis and Dissertation Repository

This thesis explores the print news media discourse surrounding the dispute between Manitoba and North Dakota over a flood mitigation plan in Devils Lake North Dakota. In order to do so, critical discourse analysis was applied to news media from a seventeen year period during the dispute. Findings were compared between media sources as well as to pertinent policy documents. The thesis finds that the political arena provided by local newspapers as well as the discourses of scale, confrontation, history, and economics had the largest effect on the dispute’s public face. A total of nine findings within these areas are …

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 …

Environmental Prediction In Canadian Cities, James Voogt

Geography & Environment Presentations

No abstract provided.