Browsing Earth and Environmental Sciences by Title
Now showing items 413-432 of 434
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Uncertainty-based multi-criteria calibration of rainfall-runoff models: a comparative study
(Springer, 2014-08-01)This study compares formal Bayesian inference to the informal generalized likelihood uncertainty estimation (GLUE) approach for uncertainty-based calibration of rainfall-runoff models in a multi-criteria context. Bayesian ... -
Uranium and Molybdenum Isotope Constraints on Ocean Redox Conditions During Deposition of the Upper Devonian Kettle Point Formation, Ontario
(University of Waterloo, 2016-10-18)The Late Devonian extinction event was among the most severe Phanerozoic mass extinction events, which led to a decline in the abundance and diversity of marine and terrestrial ecosystems, particularly tropical shallow-marine ... -
Uranium and molybdenum isotope evidence for an episode of widespread ocean oxygenation during the late Ediacaran Period
(Elsevier, 2015-05-01)To improve estimates of the extent of ocean oxygenation during the late Ediacaran Period, we measured the U and Mo isotope compositions of euxinic (anoxic and sulfidic) organic-rich mudrocks (ORM) of Member IV, upper ... -
Uranium isotope compositions of mid-Proterozoic black shales: Evidence for an episode of increased ocean oxygenation at 1.36Ga and evaluation of the effect of post-depositional hydrothermal fluid flow
(Elsevier, 2017-09-01)We report U isotope data for marine black shales of the early Mesoproterozoic Velkerri Formation (Roper Group) and late Paleoproterozoic Wollogorang Formation (Tawallah Group) from the McArthur Basin, Northern Australia. ... -
Use of Drains for Passive Control of Flow Through a Permeable Reactive Barrier
(University of Waterloo, 2007-09-28)Abstract Permeable reactive barrier technology is a cost effective means of treating near surface groundwater contaminant plumes. However, current reactive barrier technology lacks the capacity to manipulate flow rates ... -
Use of Fe isotopes to examine Fe cycling in Boreal Shield lakes: implications for cyanobacterial bloom development and ancient biogeochemical cycling
(University of Waterloo, 2024-01-26)Stable iron (Fe) isotopes have only been used recently to explore biogeochemical Fe processes in terrestrial and aquatic ecosystems. The δ⁵⁶Fe values in natural samples range from −4‰ to 4‰. An increasing number of studies ... -
Use of Liquid Chromatography - Organic Carbon Detection to Characterize Dissolved Organic Matter from a Variety of Environments
(University of Waterloo, 2012-10-26)Dissolved organic matter (DOM) is a heterogeneous mixture of organic compounds comprised mostly of carbon, oxygen, nitrogen, and hydrogen, but is often operationally defined as the concentration of dissolved organic carbon ... -
Use of N2O and its Isotopic Composition to Investigate Nitrogen Processes in Groundwater
(University of Waterloo, 2010-10-01)This study explores the use of N2O and its isotopic composition to investigate nitrogen processes in groundwater aquifers. Groundwater sampling was undertaken in 2008-2009 at two septic system sites (Long Point site and ... -
The use of stable carbon and oxygen isotopes to examine the fate of dissolved organic matter in two small, oligotrophic Canadian Shield lakes.
(University of Waterloo, 2010-02-12)Allochthonous carbon can be a large proportion of the carbon budget in northern temperate and boreal lakes. This thesis uses stable carbon and oxygen isotopes to examine the fate of allochthonous dissolved organic matter ... -
The use of stable isotopes to assess the controls on pelagic carbon basal resources in Canadian Shield lakes
(University of Waterloo, 2021-06-02)Freshwater lakes are often natural sources of greenhouse gases (GHGs) such as carbon dioxide (CO₂) and methane (CH₄) to the atmosphere, and therefore it is important to examine carbon and nutrient cycling in these complex ... -
The use of stable nitrogen and carbon isotopes to examine the sources, sinks and cycling of nitrogen in a small, artificially eutrophic Boreal lake
(University of Waterloo, 2012-05-22)This research examines components of nitrogen cycling in the artificially eutrophic Lake 227 at the Experimental Lakes Area. The components are: 1) the atmospheric sources of nitrogen to the lake through precipitation and ... -
The Use of Temperature and Environmental Isotopes as Tools to Characterize Groundwater Discharge to the Grand River, Ontario, Canada
(University of Waterloo, 2013-01-25)The Grand River Watershed, in southern Ontario, is home to approximately 900,000 people and one of the fastest growing regions in Canada; specifically, in the urban areas of Guelph, Cambridge, Kitchener, and Waterloo. ... -
Using Isotopes to Understand the Origin of Water and the Effect of Reinjection in the Los Azufers Geothermal Field in Mexico
(University of Waterloo, 2017-01-25)Los Azufers geothermal system is a convective-type geothermal system located northwest of Mexico City in the state of Michoacán at Mexico. Improvements in geochemical techniques enable a better investigation of the Tertiary ... -
Using Numerical Models for Managing Water Quality in Public Supply Wells
(University of Waterloo, 2013-08-30)Groundwater models can be useful tools to support decisions regarding the management of public water supply wells. Scientific progress and the availability of increasingly powerful computer resources provide a continuous ... -
Using The New 3D Digital Model Of Ontario’s Paleozoic Geology To Bridge Gaps In The Traditional Education Framework
(University of Waterloo, 2020-04-13)The demand for competent geoscientists and engineers is high, and the development of a new resource has addressed a gap in the traditional education framework. Spatial understanding is a key component of geoscience competency, ... -
Vadose Zone Response to Pumping in Unconfined Aquifers
(University of Waterloo, 2011-09-30)The interaction between drainage from the variably saturated zone above the water table, and the response of an unconfined aquifer to pumping has been the source of debate for many decades. While various field tests (Nwankwor ... -
The Value of Agricultural Census Data in Carbon Cycle Studie
(University of Waterloo, 2011-05-24)Agricultural census data have been identified to possess the potential to provide constraints on carbon uptake by croplands at the regional scale. In this study, we build on previous efforts and further assess this potential ... -
Variations and Sources of Atmospheric CO2 Measured at East Trout Lake, Canada
(University of Waterloo, 2016-01-15)Reducing uncertainties in projections of surface emissions of major greenhouse gases (GHGs) including CO2 relies on continuously improving our scientific understanding of the exchange processes between the atmosphere and ... -
Visualising data distributions with kernel density estimation and reduced chi-squared statistic
(Elsevier, 2017-11-01)The application of frequency distribution statistics to data provides objective means to assess the nature of the data distribution and viability of numerical models that are used to visualize and interpret data. Two ... -
Water Demand Forecasting Model Application
(University of Waterloo, 2019-01-29)Forecasting water demand requires quantifying potential relationships between relevant statistics and ambient conditions such as water price and weather. Dr Enouy (2018) demonstrates that discrete histograms can be ...