Trisalyn Nelson

• PhD Geography, Wilfrid Laurier University
• Chair at University of California, Santa Barbara

Walking is a healthy, sustainable, and economical form of transportation or recreation. Yet in North America walking is not always accessible, safe, or comfortable. A challenge to creating quality pedestrian environments is lack of data on what barriers exist and how barriers vary across communities. Our goal is to characterize pedestrian barriers...

In this paper, we estimate the number and value of adult bicycles stolen annually in the United States, and we examine the associated equity impacts. We used data from a representative survey of US adult residents and bicycle import data from the National Bicycle Dealers Association for our analysis. Our results indicate that about 2.4 million adul...

Urban planning and design aim to encourage active mobility by promoting various models that assess a city’s transportability and accessibility. In practice, these models are not attuned to a huge part of the population that have mobility impairments, therefore they uphold a flawed city design and prevent these populations from being an equal part o...

Wildlife must increasingly balance trade‐offs between the need to access important foods and the mortality risks associated with human‐dominated landscapes. Human disturbance can profoundly influence wildlife behavior, but managers know little about the relationship between disturbance–behavior dynamics and associated consequences for foraging. We...

Monitoring change is an important aspect of understanding variations in spatial–temporal processes. Recently, 'big data' on mobility, which are detailed across space and time, have become increasingly available from crowdsourced platforms. New methods are needed to best utilize the high spatial and temporal resolution of such data for monitoring pu...

Cities are making infrastructure investments to make travel by bicycle safer and more attractive. A challenge for promoting bicycling is effectively using data to support decision making and ensuring that data represent all communities. However, ecologists have been addressing a similar type of question for decades and have developed an approach to...

Dockless e-scooters were used for 86 million trips in the United States in 2019, indicating great potential as a new transportation mode in U.S. cities and on university campuses. Yet, little is known about how e-scooter users interact with people walking, bicycling, and driving. Although several studies have examined e-scooter injuries reported in...

Introduction Shared e-scooters have recently emerged as a convenient, flexible transportation option for short trips in dozens of cities and on university campuses. While there is survey evidence that e-scooting replaces walking and bicycling trips, potentially impacting physical activity (PA) levels, little is known about how e-scooter use objecti...

The increasing availability of health monitoring devices and smartphones has created an opportunity for researchers to access high-resolution (spatial and temporal) mobility data for understanding travel behavior in cities. Although information from GPS data has been used in several studies to detect transportation modes, there is a research gap in...

Safety concerns are a barrier to increasing bicycling. BikeMaps.org, a tool for crowdsourcing bicycling collisions, near misses, and falls, offers rich data on local bicycling safety concerns. Our goal is to characterize dominant bicycling safety issues reported in nine Canadian cities. We analyzed 2,513 BikeMaps.org reports (522 collisions, 151 fa...

Research on movement has increased over the past two decades, particularly in movement ecology, which studies animal movement. Taking context into consideration when analysing movement can contribute towards the understanding and prediction of behaviour. The only way for studying animal movement decision-making and their responses to environmental...

Built environment interventions have the potential to improve population health and reduce health inequities. The objective of this paper is to present the first wave of the INTErventions, Research, and Action in Cities Team (INTERACT) cohort studies in Victoria, Vancouver, Saskatoon, and Montreal, Canada. We examine how our cohorts compared to Can...

Overcoming concerns about bicycling safety is critical to increasing the health benefits of bicycling for transportation. While exposure measures are critical for monitoring and understanding bike safety, lack of spatially and temporally detailed bike counts makes it challenging to conduct robust bicycling safety studies. Crowdsourced data from sma...

Fitness apps, such as Strava, are a growing source of data for mapping bicycling ridership, due to large samples and high resolution. To overcome bias introduced by data generated from only fitness app users, researchers build statistical models that predict total bicycling by integrating Strava data with official counts and geographic data. Howeve...

Anthropogenic disturbances, including roads, are known to influence animal habitat selection and mortality. In this study, we consider the role of sensory perception in understanding why and how animals respond to disturbances. Our goal was to investigate the effect of visual perception (visibility) around roads on grizzly bear (Ursus arctos horrib...

Beginning in March 2020, the United States emerged as the global epicenter for COVID-19 cases with little to guide policy response in the absence of extensive data available for reliable epidemiological modeling in the early phases of the pandemic. In the ensuing weeks, American jurisdictions attempted to manage disease spread on a regional basis u...

Strava Metro data are used in bicycle planning, but there are concerns it overrepresents fitness activity. The data include a commute label, but spatial patterns of commuting versus recreational ridership are underexplored. Using spatial regression, we compare associations of Strava ridership by trip type. Commuting was associated with areas with m...

Smartphones and wearable devices are driving a boom in mobility data. We use data-driven tools for classifying movement data into five different travel modes (bicycle, walk, bus, motor vehicle and SkyTrain) in Vancouver and St. John's, Canada. Using data from a GPS-enabled smartphone app (Itinerum) combined with a wrist-worn accelerometer (GENEActi...

E-scooters are rapidly changing transportation in US cities and university campuses. Hailed as a convenient, inexpensive solution for “last mile” and other short trips, e-scooters are available in over 100 US cities and were used for nearly forty million trips in 2018. Yet relatively little is known about e-scooter use, including who uses them, for...

With only ∼20 % of bicycling crashes captured in official databases, studies on bicycling safety can be limited. New datasets on bicycling incidents are available via crowdsourcing applications, with opportunity for analyses that characterize reporting patterns. Our goal was to characterize patterns of injury in crowdsourced bicycle incident report...

Social media and other forms of volunteered geographic information (VGI) are used frequently as a source of fine-grained big data for research. While employing geographically referenced social media data for a wide array of purposes has become commonplace, the relevant scales over which these data apply to is typically unknown. For researchers to u...

Cities are promoting bicycling for transportation as an antidote to increased traffic congestion, obesity and related health issues, and air pollution. However, both research and practice have been stalled by lack of data on bicycling volumes, safety, infrastructure, and public attitudes. New technologies such as GPS-enabled smartphones, crowdsourc...

Many North American cities are building bicycling infrastructure. Lively discussions on social media, where people passionately support or reject bicycling infrastructure projects, provide a unique data set on attitudes towards bicycling infrastructure. Our goal is to analyse social media posts in Edmonton and Victoria, Canada as new bike infrastru...

Hidden Markov models incorporating the Potts model for the labelling process are an important class of mixture models in spatial statistics. These models have been applied to problems in statistical mechanics, image analysis and disease mapping, among other areas. Jointly estimating the model parameters, the discrete state variables and the number...

To monitor the extent and impact of human disturbances on landscapes and wildlife, managers often estimate zones of influence. Traditionally, zones of influence have been defined with constant width buffers around a disturbance; however, the importance of incorporating variation in landscape contexts and species responses is increasingly recognized...

Free access until June 04 2020 here: https://authors.elsevier.com/a/1avCCLDQwyMG Increased cycling uptake can improve population health, but barriers include real and perceived risks. Crash risk factors are important to understand in order to improve safety and increase cycling uptake. Many studies of cycling crash risk are based on combining dive...

Beginning in March 2020, the United States emerged as the global epicenter for COVID-19 cases. In the ensuing weeks, American jurisdictions attempted to manage disease spread on a regional basis using non-pharmaceutical interventions (i.e. social distancing), as uneven disease burden across the expansive geography of the United States exerted diffe...

When designing bicycle count programs, it can be difficult to know where to locate counters to generate a representative sample of bicycling ridership. Crowdsourced data on ridership has been shown to represent patterns of temporal ridership in dense urban areas. Here we use crowdsourced data and machine learning to categorize street segments into...

Measuring bicycling behaviour is critical to bicycling research. A common study design question is whether to measure bicycling behaviour once (cross-sectional) or multiple times (longitudinal). The Physical Activity through Sustainable Transport Approaches (PASTA) project is a longitudinal cohort study of over 10,000 participants from seven Europe...

The scientific method is predicated on the assumption that research designs and results can be reproduced and replicated. However, recent findings in some disciplines suggest that many studies fail to reach this standard, moving issues surrounding reproducibility and replicability forward into the research agenda of those fields. While the topic ha...

Bicyclist categorizations have been developed to sort individuals into distinct groups based on shared traits, which can help researchers and practitioners understand complex patterns of bicycling behavior. Previous categorizations have focused on bicycle facility comfort, seasonal patterns of use, and behaviors and attitudes, but not on readiness...

Traditional methods of counting bicyclists are resource-intensive and generate data with sparse spatial and temporal detail. Previous research suggests big data from crowdsourced fitness apps offer a new source of bicycling data with high spatial and temporal resolution. However, crowdsourced bicycling data are biased as they oversample recreationa...

Safety concerns are a primary deterrent to bicycling. Bicycle infrastructure is both preferred and safer for bicycling. In this paper, we examine the association between availability of bicycle infrastructure and perceptions of bicycling safety amongst over 3000 bicyclists living in six large Canadian and US cities. In three repeat cross-sectional...

Humans influence ecosystems on magnitudes that often exceed that of natural forces such as climate and geology; however, frameworks rarely include anthropogenic disturbance when delineating unique ecological regions. A critical step toward understanding, managing and monitoring human-altered ecosystems is to incorporate disturbance into ecological...

With rapid growth in bicycling, timely and spatially rich bicycling infrastructure data are essential for understanding determinants of ridership, equity of access, and potential for future developments. OpenStreetMap (OSM) is a collaborative global map that was built by volunteers and is promising for active transportation research. In this articl...

Background Urban form interventions can result in positive and negative impacts on physical activity, social participation, and well-being, and inequities in these outcomes. Natural experiment studies can advance our understanding of causal effects and processes related to urban form interventions. The INTErventions, Research, and Action in Cities...

The impacts of active transportation planning on equity are often overlooked, potentially leading to disparities in who receives benefits of infrastructure investment. This study examined income inequalities in spatial access to bicycling infrastructure in three mid-sized Canadian cities: Victoria and Kelowna (British Columbia), and Halifax (Nova S...

Citizen science observations represent a significant and growing source of species and ecosystem knowledge. These data have potential to support traditional surveys. Databases of citizen observations of wildlife are growing, but how to use this information for scientific purposes is less clear owing to uncertainty in sampling distribution and data...

Multiple studies have associated the density of alcohol establishments with crime. What is not well understood is the influence of establishment patron capacity on the magnitude of crime in an area, or how the spacing of liquor primary establishments impacts crime levels. Using a Poisson spatial lag model, we estimated how patron capacity of on-pre...

The R package stampr implements functions for analyzing movement in mapped polygon data. Methods described in this paper include deriving change events based on spatial relationships, plotting change events, summarizing measures of distance and direction of movement, characterizing changes in polygon shape changes, and characterizing sequences of p...

Conventional bicycling data have critical limitations related to spatial and temporal scale when analyzing bicycling as a transport mode. Novel crowdsourced data from smartphone apps have the potential to overcome those limitations by providing more detailed data. Questions remain, however, about whether crowdsourced data are representative of gene...

Cycling is a sustainable mode of transportation with numerous health, environmental and social benefits. Investments in cycling specific infrastructure are being made with the goal of increasing ridership and population health benefits. New infrastructure has the potential to impact the upgraded corridor as well as nearby street segments and cyclin...

Introduction Bicycling is promoted as a transportation and population health strategy globally. Yet bicycling has low uptake in North America (1%–2% of trips) compared with European bicycling cities (15%–40% of trips) and shows marked sex and age trends. Safety concerns due to collisions with motor vehicles are primary barriers. To attract the broa...

Volunteered geographic information (VGI) is the use of digital tools to collect, analyze, and share geographic information that was provided by individuals. Recent advances in digital communication tools and applications have led to unprecedented advances for VGI. Because official credentials are not required, VGI can include the experiences and pe...

Many cities are making significant financial investments in cycling infrastructure with the aim of making cycling safer for riders of all ages and abilities. Methods for evaluating cycling safety tend to summarize average change for a city or emphasize change on a single road segment. Few spatially explicit approaches are available to evaluate how...

There has been growing interest in using volunteered geographic information (VGI) for transportation planning, such as route data from fitness tracking applications and route mapping smartphone applications, as a compliment to traditional data collection approaches. In particular, cycling safety data from traditional sources are limited since bike...

Comprehensive mapping of shore-zone morphology supports evaluation of shore habitat, monitoring of environmental hazards, and characterization of the transfer of nutrients between marine and terrestrial environments. This article shows how rich shore-zone morphological metrics can be derived from LIDAR terrain models and evaluates the application o...

In forestry, many fundamental spatial processes cannot be measured directly and data on spatial patterns are used as a surrogate for studying processes. To characterize the outcomes of a dynamic process in terms of a spatial pattern, we often consider the probability of certain outcomes over a large area rather than on the scale of the particular p...

Entertainment districts have high crime rates. Offences peak on the weekend during the operating hours of on-premises drinking establishments. To determine if proactive policing from May 1st to August 31st reduced the spatial density (kernel) or annual frequency of liquor infractions and assaults in Vancouver British Columbia Granville St. Entertai...

Global biodiversity is undergoing rapid decline due to direct and indirect anthropogenic impacts to species and ecosystems. Marine species, in particular, are experiencing accelerated population declines leading to many species being considered at risk by regional, national, and international standards. As one conservation approach, decisions made...

People generate massive volumes of data on the Internet about cities. Researchers may engage these crowds to fill data gaps and better understand and inform planning decisions. Crowdsourced tools for data collection must be supported by outreach; however, researchers typically have limited experience with marketing and promotion. Our goal is to pro...

2017. Intrapopulation diversity in isotopic niche over landscapes: Spatial patterns inform conservation of bear–salmon systems. Ecosphere 8(6): Abstract. Intrapopulation variability in resource acquisition (i.e., niche variation) influences population dynamics, with important implications for conservation planning. Spatial analyses of niche variati...

The productivity and phenology of vegetation are spatially and temporally variable ecosystem functions. Monitoring spatial–temporal patterns in these functions can improve our understanding of global change and natural ecosystem variability and inform management actions. Researchers typically focus on temporal changes within or among static regions...

Real and perceived concerns about cycling safety are a barrier to increased ridership in many cities. Many people prefer to bike on facilities separated from motor vehicles, such as multiuse trails. However, due to under-reporting, cities lack data on bike collisions, especially along greenways and multiuse paths. We used a crowdsourced cycling inc...

Landscape regionalization approaches are frequently used to summarize and visualize complex spatial patterns, environmental factors, and disturbance regimes. However, landscapes are dynamic and contemporary regionalization approaches based on spatial patterns often do not account for the temporal component that may provide important insight on dist...

Background: Harmful algal blooms produce paralytic shellfish toxins that accumulate in the tissues of filter feeding shellfish. Ingestion of these toxic shellfish can cause a serious and potentially fatal condition known as paralytic shellfish poisoning (PSP). The coast of British Columbia is routinely monitored for shellfish toxicity, and this stu...

Official sources of cyclist safety data suffer from underreporting and bias. Crowdsourced safety data have the potential to supplement official sources and to provide new data on near-miss incidents. BikeMaps.org is a global online mapping tool that allows cyclists to record the location and details of near misses and collisions they experience. Ho...

Ecologically based strategies for climate change adaptation can be constructively integrated into a terrestrial conservation assessment for Canada's boreal forest, one of Earth's largest remaining wilderness areas. Identifying solutions that minimize variability in projected vegetation productivity may represent a less risky conservation investment...

Ecological studies can be limited by the mismatch in spatial-temporal scales between wildlife GPS telemetry data, collected sub-hourly, and the large-area maps used to identify disturbances, generally updated annually. Recent advancements in remote sensing, data fusion modeling, mapping, and change detection approaches offer environmental data prod...

Human occupation is usually associated with degraded landscapes but 13,000 years of repeated occupation by British Columbia's coastal First Nations has had the opposite effect, enhancing temperate rainforest productivity. This is particularly the case over the last 6,000 years when intensified intertidal shellfish usage resulted in the accumulation...

The analysis of interaction between movement trajectories is of interest for various domains when movement of multiple objects is concerned. Interaction often includes a delayed response, making it difficult to detect interaction with current methods that compare movement at specific time intervals. We propose analyses and visualizations, on a loca...

Globally, alcohol consumption has considerable public health, social, and economic costs. Per capita alcohol sales data are the most accurate means of quantifying consumption, but can overestimate local consumption in areas of high tourism. The goal of this research was to investigate a method for adjusting estimates of per capita alcohol consumpti...

Cycling volumes are necessary to understand what influences ridership and are essential for safety studies. Traditional methods of data collection are expensive, time consuming, and lack spatial and temporal detail. New sources have emerged as a result of crowdsourced data from fitness apps, allowing cyclists to track routes using GPS enabled cell...

This research evaluates the efficacy of candidate reserves in boreal ecosystems with respect to a long term record of remote sensing derived productivity based on the dynamic habitat index (DHI) generated using Advanced Very High Resolution Radiometer (AVHRR) data (1987-2007) and compared differences related to reserve location (stratified by land...

Traditionally, forest inventory and ecosystem mapping at local to regional scales rely on manual interpretation of aerial photographs, based on standardized, expert-driven classification schemes. These current approaches provide the information needed for forest ecosystem management but constrain the thematic and spatial resolution of mapping and a...

Advances in GPS telemetry and remote sensing technologies provide researchers with abundant data that can be used to investigate detailed questions about wildlife behavior. Existing methods for linking wildlife movement to remotely sensed landscape data generally rely on the application of subjectively derived distance thresholds to represent proxi...

Climate drives ecosystem processes and impacts biodiversity. Biodiversity patterns over large areas, such as Canada's boreal, can be monitored using indirect indicators derived from remotely sensed imagery. In this paper, we characterized the historical space–time relationships between climate and a suite of indirect indicators of biodiversity, kno...

Background: There is no safe concentration of radon gas, but guideline values provide threshold concentrations that are used to map areas at higher risk. These values vary between different regions, countries, and organizations, which can lead to differential classification of risk. For example the World Health Organization suggests a 100 Bq m(-3)...

Alcohol consumption often leads to elevated rates of violence yet alcohol access policies continue to relax across the globe. Our review establishes the extent alcohol policy can moderate violent crime through alcohol availability restrictions. Results were informed from comprehensive selection of peer-reviewed journals from 1950 to October 2015. O...

Background: The study of inter-individual interactions (often termed spatial-temporal interactions, or dynamic interactions) from remote tracking data has focused primarily on identifying the presence of such interactions. New datasets and methods offer opportunity to answer more nuanced questions, such as where on the landscape interactions occur...

Modelling the relationship between alcohol consumption and crime generates new knowledge for crime prevention strategies. Advances in data, particularly data with spatial and temporal attributes, have led to a growing suite of applied methods for modelling. In support of alcohol and crime researchers we synthesized and critiqued existing methods of...

In the Rocky Mountain eastern slopes of Alberta, Canada, grizzly bears (Ursus arctos horribilis Ord, 1815) live in a landscape heavily impacted by industrial development and human disturbance. We characterized the role of changing habitat quality and new disturbance features on patterns of grizzly bear seasonal home-range fidelity and drift by comp...

Remotely sensed image composites that are pixel based rather than scene based are increasingly feasible to use over large areas and fine spatial resolutions. For large jurisdictions that utilize remotely sensed imagery for ecosystem mapping and monitoring, pixel-based composites enable a wider range of applications, at higher quality. The goal of t...

In this paper, we introduce a new metric for evaluating feasible VGI study areas and the appropriateness of different aggregation unit sizes through three different components of data quality: coverage, density, and user-heterogeneity. Two popular sources of passive VGI are used for initial testing of the metric: Twitter and Flickr. We compare the...

Here we describe and apply a semi-automated, object-based method for extracting vector-building footprint polygons from aerial photographs (orthophotos) within urban settings. The approach integrates the use of high resolution orthophotos and image segmentation software and is compared with methods using Light Detection and Ranging (LiDAR) as the s...

Operational use of the ecosystem service (ES) concept in conservation and planning requires quantitative assessments based on accurate mapping of ESs. Our goal is to review spatial assessments of ESs, with an emphasis on the socioecological drivers of ESs, the spatial datasets commonly used to represent those drivers, and the methodo-logical approa...

The goal of this research was to model the potential impact of climate change on food production, in the Fraser Valley and Peace River regions of British Columbia (BC), using historical crop yield and climate data. We identified eight indicator crops of importance for these regions of BC and utilized historical Census of Agriculture and climate dat...

There are many public health benefits to cycling, such as chronic disease reduction and improved air quality. Real and perceived concerns about safety are primary barriers to new ridership. Due to limited forums for official reporting of cycling incidents, lack of comprehensive data is limiting our ability to study cycling safety and conduct survei...

Radon is a carcinogenic radioactive gas produced by the decay of uranium. Accumulation of radon in residential structures contributes to lung cancer mortality. The goal of this research is to predict residential radon vulnerability classes for the province of British Columbia (BC) at aggregated spatial units. Spatially referenced indoor radon conce...

Geographic information systems (GIS) are widely used for mapping wildlife movement patterns, and observed wildlife locations are surrogates for inferring on wildlife movement and habitat selection. We present a new approach to mapping areas where wildlife exhibit sustained use, which we term slow movement areas (SMAs). Nested within the habitat sel...