
Electronic Theses and Dissertations
Date
2025
Document Type
Dissertation
Degree Name
Doctor of Philosophy
Department
Civil Engineering
Committee Chair
Claudio Meier
Committee Member
Brian Waldron
Committee Member
Farhad Jazaei
Committee Member
Scott Schoefernacker
Committee Member
Thomas Goebel
Abstract
The interactions between groundwater and surface water significantly influence water quality, availability, and ecosystem health worldwide. However, characterizing these exchanges remains challenging due to their occurrence across multiple spatial and temporal scales. This research addresses these challenges for lowland channelized streams, where anthropogenic modifications have altered natural exchange patterns. First, a systematic evaluation of field methods led to the development of an integrated characterization approach combining electromagnetic induction, potentiomanometers, and temperature profilers. Application of this methodology along 19 kilometers of the Loosahatchie River and Nonconnah Creek in Shelby County, Tennessee, revealed distinct patterns of stream-aquifer connectivity influenced by both geological conditions and anthropogenic modifications, including the identification of a critical 300-meter reach of enhanced downward flow coinciding with historical borrow pit locations. Second, high-resolution monitoring of the streambed temperature using a 36 m x 36 m array of sensors at six depths challenged traditional one-dimensional flow assumptions. Results demonstrated that flow patterns vary systematically with depth, showing complex three-dimensional behavior in shallow zones (< 0.35 m) but more stable conditions at greater depths. While individual temperature measurements showed local variability, the overall pattern of upward flow matched potentiomanometer measurements, suggesting that temperature methods can capture dominant exchange patterns when properly implemented with multiple measurement depths and appropriate spatial distribution. This research advances both theoretical understanding and practical characterization of stream-aquifer interactions while providing guidance for water resource management in modified stream systems worldwide. Its findings highlight the importance of considering historical context when evaluating contemporary flow patterns and demonstrate how careful integration of complementary methods can reveal critical zones of enhanced connectivity that might otherwise go undetected.
Library Comment
Dissertation or thesis originally submitted to ProQuest.
Notes
Open Access
Recommended Citation
Ledesma, Benjamin, "FROM THEORY TO PRACTICE: UNDERSTANDING AND CHARACTERIZING STREAM-AQUIFER EXCHANGE IN ANTHROPOGENICALLY MODIFIED FLUVIAL SYSTEMS" (2025). Electronic Theses and Dissertations. 3707.
https://digitalcommons.memphis.edu/etd/3707
Comments
Data is provided by the student.”