Date Available

12-15-2022

Year of Publication

2022

Document Type

Doctoral Dissertation

Degree Name

Doctor of Philosophy (PhD)

College

Arts and Sciences

Department/School/Program

Earth and Environmental Sciences (Geology)

Advisor

Dr. Andrea M. Erhardt

Co-Director of Graduate Studies

Dr. Alan E. Fryar

Abstract

Naturally occurring stable isotopes of water and introduced water tracers allow researchers to examine water pathways and better understand spatial and temporal variability in water sources. Trends in naturally occurring stable isotope values can function not only as a tracer for precipitation patterns and moisture recycling but also as a confirmation of municipal data. Additionally, these data can provide an early signal for the effects of climate change on these sources, reducing uncertainty from physical measurements. To further assess water pathways, introduced tracers can be used to investigate surface and below ground surface flow for streams and rivers.

In chapter 2, stable isotope values from collected precipitation in Kyiv (Ukraine) and Cherkasy (Ukraine) were compared with published 3H data for Kyiv from the year 2000. These data show an influence of the North Atlantic Oscillation (NAO) and provide information about processes affecting precipitation along the storm trajectory. The ๐›ฟ18O values also show a correlation with temperature, indicating that precipitation patterns may be affected by the rising temperatures in the region, as predicted by recent regional studies using Representative Concentration Pathway scenarios. When compared to backtracked storm trajectory and NAO data, clear relationships emerged between water isotope ratios, storm paths, and likely moisture recycling. Overall, ๐›ฟ2H, ๐›ฟ18O, 3H, and storm trajectory data provide more regional information on water vapor processes, improving climate-change-driven precipitation forecasts in Ukraine.

In chapter 3, tap water, surface water, and groundwater were collected over 14 months in Kyiv and nearby Boryspil, Brovary, and Boyarka. Stable isotope values from the tap water for each district in Kyiv show a general seasonal trend in water sources, with more groundwater used in the supply in the winter for most districts. Spatially, groundwater use increases from south to north in the left-bank districts in Kyiv city and groundwater use generally decreases from south to north in the right-bank districts. As precipitation patterns shift and temperatures increase, the reliance on particular water sources may need to shift as well. Overall, ๐›ฟ2H and ๐›ฟ18O data provide a baseline expectancy for current water use throughout the year and, from this, deviations can be assessed early.

In chapter 4, coupled conservative and reactive tracers were used to characterize both adsorption and transient storage in an urban stream pre- and post-restoration. Many stream restoration projects are undertaken to increase water residence times and create environments for contaminant degradation, but direct comparisons of how restoration techniques achieve these goals are limited. This study found that each restoration technique increased transient storage when compared to the pre-restoration conditions. However, as the restoration styles were in a sequential order, it is possible that storage from previous sections could also affect concentrations recovered downstream. Storage for both the regenerative design and the single channel design included adsorption and transient storage. The multi-channel design had the primary control of transient storage.

Digital Object Identifier (DOI)

https://doi.org/10.13023/etd.2022.422

Funding Information

These studies were funded by a Fulbright Student Research Award in 2019, a Karri Casner Environmental Sciences Fellowship in 2019, and a Geological Society of America Graduate Student Research Grant in 2019.

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