Colby M. Steelman

Colby M. Steelman
University of Waterloo | UWaterloo · Department of Earth and Environmental Sciences

PhD

About

56
Publications
8,500
Reads
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708
Citations
Citations since 2016
29 Research Items
472 Citations
2016201720182019202020212022020406080
2016201720182019202020212022020406080
2016201720182019202020212022020406080
2016201720182019202020212022020406080
Introduction
My research focuses on the dynamic processes of hydrologic environments. I am particularly interested in hydrogeophysical characterization and monitoring of hydrogeologic systems, and understanding the role of process dynamics in the water cycle.
Additional affiliations
May 2016 - February 2017
University of Guelph
Position
  • Researcher
February 2012 - April 2016
University of Guelph
Position
  • PostDoc Position

Publications

Publications (56)
Article
Full-text available
The Liard Basin, in northwest Canada, contains one of Canada’s largest natural gas reserves. There are concerns about degradation of Dunvegan Formation groundwater quality, which is the basins main shallow freshwater aquifer, as a consequence of oil and gas development. Previous lithostratigraphic studies interpreted the Dunvegan as conglomeratic a...
Article
The development of a three-dimensional (3D) hydrogeologic site model requires detailed knowledge of an area's hydrostratigraphy, information typically obtained from core logs, historical well records, outcrop mapping, and/or surface geophysics. Due to the high cost of drilling, a 3D model may rely on various statistical techniques to interpolate li...
Article
Full-text available
Bedrock rivers represent a hydrogeological environment in which surface water flows along an exposed bedrock surface. Studies of hyporheic exchange have exclusively involved rivers composed of unconsolidated fluvial sediments, leaving a critical knowledge gap. This study evaluates the conditions that could support bedform‐scale hyporheic exchange w...
Article
Buried bedrock valleys are common erosional features in northern mid-latitude environments forming through glaciofluvial or paleoalluvial processes and are typically infilled by Quaternary-aged sediments. The erosional extent and geometry of the valley including a weathered interface, along with sediment infill that can contain complex sequences of...
Article
A complex mixture of dissolved organic contaminants, emanating from a many decades-old, residual, dense nonaqueous phase liquid (DNAPL) source, migrates through unconfined, moderately heterogeneous, glacial-derived sediments and sedimentary rock in a residential area of Dane County, Wisconsin, USA. A portion of this contaminant plume intersects a l...
Presentation
Full-text available
Bedrock rivers represent a hydrogeological environment in which surface water flows along an exposed bedrock surface. Studies of hyporheic exchange have exclusively involved rivers comprised of unconsolidated fluvial sediments, leaving a critical gap in our understanding of groundwater-surface water interactions. Our study evaluates the conditions...
Research Proposal
Full-text available
Abstract submission deadline: 2020-01-15 There is an abundance of case studies on various aquifers, and aquifer settings with a full range of data support depending upon study objectives, scale, and funding. Near surface aquifers, particularly those in surficial sediment are commonly classified by a combination of sediment-landform terminology; w...
Article
Geophysical methods have the capacity to detect and characterize gas-phase dynamics in groundwater. Suitable methods can be deployed at surface or within boreholes depending on the required depth of investigation, spatial/temporal resolution, and geologic conditions. While the application of geophysical methods to monitor immiscible phase contamina...
Poster
Northern cold regions are especially susceptible to climatic variations. As a result of global climate change, permafrost degradation may be occurring rapidly and is important to monitor. Landscape changes related to both natural and anthropogenic factors can be indicators of permafrost degradation. Using electrical geophysical methods, we aimed...
Article
Subsurface leakage of natural gas from petroleum wells can impact freshwater aquifers. Accurate prediction of gas migration in the subsurface will depend on knowledge of permeability, porosity, and flow system conditions. A series of two-dimensional numerical multi-phase flow simulations (CFbio) were conducted to investigate the role of multi-phase...
Research
Full-text available
Download and open .gif in web browser to watch a surface water-groundwater interaction transport simulation of a conservative tracer within a bedrock river (Realization no. 23).
Poster
Full-text available
The effects of river channel characteristics on hydrostatic and hydrodynamic pressure variations that drive hyporheic exchange have been the focus of numerous studies over the past decade. The hydrogeological settings of such studies have exclusively considered alluvial rivers, where the riverbed contains layers of unconsolidated fluvial sediment....
Conference Paper
Full-text available
ERT IMAGING OF SUBSURFACE STRUCTURE OF A SINKHOLE IN GREENE COUNTY, MISSOURI Shishay Kidanu, Missouri S&T; Evgeniy Torgashov, Missouri S&T; Neil Anderson, Missouri S&T Thousands of sinkholes have been identified in the state of Missouri; Greene County, in particular, is one of the counties in the state most known for the occurrence of sinkholes....
Article
This study evaluates the utility of ambient temperature profiles collected in sealed bedrock boreholes to assess variability in groundwater flow in discretely fractured shallow bedrock environments. A conceptual model for groundwater flow and groundwater-surface water temperature conditions and their interaction in a temperate climate is developed...
Article
Full-text available
Fugitive methane (CH4) leakage associated with conventional and unconventional petroleum development (e.g., shale gas) may pose significant risks to shallow groundwater. While the potential threat of stray (CH4) gas in aquifers has been acknowledged, few studies have examined the nature of its migration and fate in a shallow groundwater flow system...
Article
Full-text available
Bedrock rivers occur where surface water flows along an exposed rock surface. Fractured sedimentary bedrock can exhibit variable groundwater residence times, anisotropic flow paths, and heterogeneity, along with diffusive exchange between fractures and rock matrix. These properties of the rock will affect thermal transients in the riverbed and grou...
Article
Organic solvent (i.e., dense nonaqueous phase liquid, DNAPL) migration in the subsurface is known to be extremely sensitive to geologic heterogeneity. There is often a focus on heterogeneity that results from changing depositional conditions over short spatial scales. Similar or even more extreme spatial heterogeneity can result postdeposition due...
Article
Full-text available
Expansion of shale gas extraction has fuelled global concern about the potential impact of fugitive methane on groundwater and climate. Although methane leakage from wells is well documented, the consequences on groundwater remain sparsely studied and are thought by some to be minor. Here we present the results of a 72-day methane gas injection exp...
Article
Full-text available
Buried bedrock valleys infilled with Quaternary-aged sediment have the potential to become productive aquifers due to prevalent sand and gravel deposits often associated with these topographic lows. In areas where groundwater is drawn from the underlying bedrock aquifer, buried bedrock channels may significantly affect the spatial distribution of r...
Article
Full-text available
Bedrock rivers occur where surface water flows along an exposed rock surface. Fractured sedimentary bedrock can exhibit variable groundwater residence times, anisotropic flow paths, heterogeneity, along with diffusive exchange between fractures and rock matrix. These properties of the rock will affect thermal transients in the riverbed and groundwa...
Poster
Full-text available
The expansion of unconventional natural gas extraction (e.g. from shale) has raised concerns over potential impacts of fugitive methane migration on shallow groundwater. To provide direct insight into the effect of methane (CH4) and the microbial processes involved in CH4 removal from contaminated aquifers, we performed metagenomic and microbiologi...
Conference Paper
Fugitive methane associated with shale gas development became a controversial issue of significant public and scientific concern following a decade of intensive and widespread development. Subsequent research activity has significantly advanced our understanding of both natural and anthropogenic methane in the subsurface. In particular a suite of a...
Conference Paper
Full-text available
Fractured sedimentary bedrock aquifers represent an important source of water for many communities around the world. Although the effective porosities of these aquifers are extremely low relative to their unconsolidated counterparts, the existence of dense networks of interconnected fractures, dissolution-enhanced conduits or karst features can res...
Article
Full-text available
Bedrock rivers exhibit very different hydraulic and ecological regimes compared to alluvial rivers. Groundwater–surface water interaction in rivers that flow directly on sedimentary bedrock surfaces with exposed fracture and conduit networks is generally based on alluvial river conceptual models. However, the dual and triple porosity systems of sed...
Poster
While the capacity of both electromagnetic induction (EMI) and electrical resistivity tomography (ERT) to monitor shallow soil moisture dynamics has been extensively examined, there have been few studies comparing the results of these two techniques. These comparative studies have primarily treated ERT as the more reliable method and focussed on th...
Article
[1] A major challenge in vadose zone hydrology is to obtain accurate information on the temporal changes of the vertical soil water distribution and its feedback with the atmosphere and groundwater. A state of the art coupled hydrogeophysical inversion scheme is applied to evaluate soil hydraulic properties of a synthetic model and a field soil in...
Article
It has been recently demonstrated that the early-time portion of the ground-penetrating radar (GPR) signal, consisting of the direct air and ground wave events, is dependent on the shallow subsurface bulk electromagnetic properties of the material; these properties are strongly controlled by the water content in this material. While several control...
Article
In many hydrological applications, ground-wave velocity measurements are increasingly used to map and monitor shallow soil water content. In this study, we propose an automated spectral velocity analysis method to determine the direct ground-wave (DGW) velocity from common midpoint (CMP) or multi-offset ground-penetrating radar (GPR) data. The meth...
Article
Surface ground-penetrating radar (GPR) techniques have been used by a number of previous researchers to characterize soil moisture content in the vadose zone. However, limited temporal sampling and low resolution near the surface in these studies greatly impedes the quantitative analysis of vertical soil moisture distribution and its associated dyn...
Article
Soil moisture measurement techniques are of utmost importance to vadose zone hydrologists. Surface hydrogeophysical methods, such as ground-penetrating radar (GPR), have the capacity to provide field-scale soil moisture information across a range of depth scales. This paper presents an extensive field study using multi-frequency (i.e., 225. MHz, 45...
Article
A major issue in vadose zone hydrology is the characterization of the vertical soil moisture distribution within this region and the nature of its coupling with soil moisture variations at the surface. We have evaluated the use of high-frequency (i.e., 900 MHz) surface ground penetrating radar (GPR) as a non-invasive method for obtaining this infor...
Article
High-resolution electrical resistivity tomography (ERT) and electromagnetic induction (EMI) surveys are currently being used to monitor changes in shallow moisture conditions at five different locations within a clayey vineyard site located in Vineland, Ontario, Canada. These geophysical measurements have been collected every 2-3 weeks since late s...
Article
Full-text available
This paper presents a multi-year field study in which high-frequency 900 MHz reflection traveltime measurements were used to monitor vertical soil moisture distribution in the upper 3.0 m of vadose zone. GPR reflection profiles and common-midpoint (CMP) soundings were collected over the complete annual cycle of soil conditions characterized by nume...
Article
Soil water content measurement using ground-penetrating radar (GPR) requires an appropriate petrophysical relationship between the dielectric permittivity and volumetric water content of the soil. The suitability of different relationships for GPR soil water content estimation has not been thoroughly investigated under natural field conditions for...
Article
Direct ground wave (DGW) measurements obtained with ground-penetrating radar have been used in a number of previous studies to estimate volumetric water content in the shallow soil zone; however, these studies have generally involved controlled field experiments or measurements collected across limited natural ranges of soil moisture conditions. To...
Article
We have used reflection profiles and common-midpoint (CMP) soundings with 900 MHz ground-penetrating radar (GPR) to monitor freezing and thawing processes during winter seasonal periods at two separate sites located in Ontario, Canada. GPR responds to the large contrast in dielectric permittivity between liquid water and ice. The profiles reveal th...
Conference Paper
Previous studies have demonstrated the capacity of electromagnetic geophysical methods for estimating soil moisture content. In this study, electromagnetic induction (EMI) and ground-penetrating radar (GPR) measurements were coincidently collected along a fixed survey line to evaluate temporal changes in apparent electrical conductivity and electro...
Conference Paper
High-frequency ground-penetrating radar (GPR) surveys were used to investigate temporal water content variations in a vertical soil column characterized by stratified clean sand deposits over multiple annual cycles. Reflection profiling and common-midpoint (CMP) soundings were coincidently performed using 900 MHz antennas across a 2 m intensive mon...
Article
Freeze and thaw processes are important components in characterizing glacial, periglacial and frozen ground environments, and hence the response of cryospheric regions to climate change. High-frequency ground-penetrating radar is particularly well suited for monitoring the freezing and thawing processes within the shallow subsurface (i.e., < 1 m de...
Article
High frequency ground-penetrating radar direct ground waves were used to monitor the seasonal development of a thin, high velocity frozen soil layer over a wet low velocity unfrozen substratum. During the freezing process, the progressive attenuation of a low velocity direct ground wave and the subsequent development of a high velocity direct groun...
Article
High frequency GPR is particularly well suited for monitoring the shallow subsurface due to its non-invasive nature and ability to measure the soil water content. In case of precipitation or thawing, a low velocity waveguide can be induced due to the strong influence of the change in water content on the radar velocity. In this way, the lower subst...
Article
Ground penetrating radar (GPR) common mid-point (CMP) soundings provide a non-invasive method of monitoring vertical variations in near-surface soil water content. This process is achieved by determining the velocity structure corresponding to the normal move-out (NMO) of hyperbolic reflection events in the CMP sounding. An estimate of volumetric s...
Article
Soil frost zones are an important component in spring runoff and ground water recharge studies. The depth and distribution of seasonal frost zones influence the dynamics of spring infiltration. Therefore, knowledge of the temporal and spatial distribution of soil frost zones is an important component in modeling groundwater/surface water recharge....
Article
Dispersed ground penetrating radar (GPR) waves contain important information about the subsurface. For GPR applications, the source and receiver antennas are commonly placed on the earth surface. For a surface waveguide to be present, the lower substrate medium should have either a much larger permittivity/conductivity or a lower permittivity than...
Article
Ground-penetrating radar (GPR) provides a non-invasive method of monitoring temporal and spatial variations in soil water content in the shallow vadose zone. The electromagnetic wave velocity is governed by the bulk dielectric permittivity of the soil, which is strongly influenced by the amount of liquid water present in the material. Accurate esti...
Article
High frequency GPR (225-900 MHz) was used for the high resolution, non-invasive monitoring of freeze and thaw processes in the shallow subsurface (i.e., within 1.5 meters of the surface) at three sites with different soil types (sand, sandy loam and silt loam). Both common midpoint (CMP) gathers and constant offset reflection profiles were repeated...

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Projects (4)
Project
This project focuses on understanding the physical properties that govern hyporheic exchange in bedrock rivers.