{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/116145"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/116145","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Upstream Population Gradient Drives Freshwater Salinization in the Occoquan Watershed","abstract":"Increased salinization of inland freshwater resources is present on a global scale, but is pro- gressing rapidly in the densely populated Mid-Atlantic United States. This phenomenon threatens aquatic health, ecosystem services and functionality, and can alter the percep- tion of potable drinking water. The Occoquan watershed, located in Northern Virginia has experienced rapid urbanization across recent decades and is now confronted with rising salinization. Various stakeholders in the area have focused efforts to quantify the drivers of salinization in order to take corrective action to preserve this resource. To aid these efforts, urbanization's relationship with in-stream salinity was analyzed, where its exerted influence was found to be dependent upon overland hydrologic flowpaths which connect urban areas to stream networks. The analysis was then broadened to Multiple Linear Regression models of urban and climatological drivers to statistically quantify each driver's relative influence on in-stream salinity. The models demonstrated that urbanization is the primary driver, where rainfall and roadway deicer application were also found to be significant. The model was then used to predict the magnitude of salinization in the Occoquan watershed to a time horizon of 2040 based on expected population growth as well as two anticipated climate scenarios. Finally, the analytical framework produced in this research was generated with scalability in mind, such that it can potentially be utilized as a watershed-scale screening tool accross the Mid-Atlantic, to inform proactive, regionally appropriate management decisions.","abstract_html":"Increased salinization of inland freshwater resources is present on a global scale, but is pro- gressing rapidly in the densely populated Mid-Atlantic United States. This phenomenon threatens aquatic health, ecosystem services and functionality, and can alter the percep- tion of potable drinking water. The Occoquan watershed, located in Northern Virginia has experienced rapid urbanization across recent decades and is now confronted with rising salinization. Various stakeholders in the area have focused efforts to quantify the drivers of salinization in order to take corrective action to preserve this resource. To aid these efforts, urbanization's relationship with in-stream salinity was analyzed, where its exerted influence was found to be dependent upon overland hydrologic flowpaths which connect urban areas to stream networks. The analysis was then broadened to Multiple Linear Regression models of urban and climatological drivers to statistically quantify each driver's relative influence on in-stream salinity. The models demonstrated that urbanization is the primary driver, where rainfall and roadway deicer application were also found to be significant. The model was then used to predict the magnitude of salinization in the Occoquan watershed to a time horizon of 2040 based on expected population growth as well as two anticipated climate scenarios. Finally, the analytical framework produced in this research was generated with scalability in mind, such that it can potentially be utilized as a watershed-scale screening tool accross the Mid-Atlantic, to inform proactive, regionally appropriate management decisions.","abstract_has_math":false,"creators":["Stacy, Melissa Renee"],"institution":"Virginia Tech","degree_name":"Master of Science","degree_level":"masters","degree_discipline":"Environmental Engineering","degree_department":"Environmental Science and Engineering","school":null,"contributors":[],"advisors":[],"committee_chairs":["Grant, Stanley"],"committee_members":["Rippy, Megan A.","Saksena, Siddharth"],"year":2023,"date_issued":"2023-08-28","date_published":"2023-08-28","updated_at":"2026-07-22T22:20:43Z","subjects":["Occoquan","freshwater salinity","urbanization","ecosystem health","human health"],"languages":["en"],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["vt_gsexam:38414"],"render_values":[{"text":"vt_gsexam:38414","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/10919/116145","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.committeechair","label":"Committee Chair","values":["Grant, Stanley"]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Rippy, Megan A.","Saksena, Siddharth"]},{"key":"dc:contributor.department","label":"Department","values":["Environmental Science and Engineering"]},{"key":"dc:creator","label":"Author","values":["Stacy, Melissa Renee"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2023-08-29T08:00:19Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2023-08-29T08:00:19Z"]},{"key":"dc:date.issued","label":"Date","values":["2023-08-28"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Tech"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Environmental Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["masters"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Virginia Polytechnic Institute and State University"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Occoquan","freshwater salinity","urbanization","ecosystem health","human health"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["In Copyright"]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://rightsstatements.org/vocab/InC/1.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["vt_gsexam:38414"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/10919/116145"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Increased salinization of inland freshwater resources is present on a global scale, but is pro- gressing rapidly in the densely populated Mid-Atlantic United States. This phenomenon threatens aquatic health, ecosystem services and functionality, and can alter the percep- tion of potable drinking water. The Occoquan watershed, located in Northern Virginia has experienced rapid urbanization across recent decades and is now confronted with rising salinization. Various stakeholders in the area have focused efforts to quantify the drivers of salinization in order to take corrective action to preserve this resource. To aid these efforts, urbanization's relationship with in-stream salinity was analyzed, where its exerted influence was found to be dependent upon overland hydrologic flowpaths which connect urban areas to stream networks. The analysis was then broadened to Multiple Linear Regression models of urban and climatological drivers to statistically quantify each driver's relative influence on in-stream salinity. The models demonstrated that urbanization is the primary driver, where rainfall and roadway deicer application were also found to be significant. The model was then used to predict the magnitude of salinization in the Occoquan watershed to a time horizon of 2040 based on expected population growth as well as two anticipated climate scenarios. Finally, the analytical framework produced in this research was generated with scalability in mind, such that it can potentially be utilized as a watershed-scale screening tool accross the Mid-Atlantic, to inform proactive, regionally appropriate management decisions."]},{"key":"dc:description.abstractgeneral","label":"General Abstract","values":["Increased salinization of inland freshwater resources is present on a global scale, but is progressing rapidly in the densely populated Mid-Atlantic United States. Driven by the engineered systems that define our modern world, this phenomenon threatens aquatic health, ecosystem services and functionality, and can alter the perception of potable drinking water. The Occoquan watershed, located in Northern Virginia has experienced rapid urbanization across recent decades and is now confronted with rising salinization. Various stakeholders in the area have focused efforts to quantify the drivers of salinization in order to take corrective action to preserve this resource. The analyses completed in this body of work act to model and statistically analyze the drivers which foster salinization in the Occoquan. The analyses demonstrated that while climatological factors drive salinity in the Occoquan, urbanization is the primary driver, where its exerted influence is dependent upon overland hydrologic flowpaths which connect urban areas to stream networks. Further analyses were completed to project salinization to a time horizon of 2040 based on expected population growth as well as two anticipated climate scenarios to predict the magnitude of salinization in the Occoquan watershed in decades to come. These results indicated that anticipated levels of in-stream salinity will increase across most sampling stations in coming years. Finally, the analytical framework produced in this research was generated with scalability in mind, such that it can potentially be utilized as a watershed-scale screening tool accross the Mid-Atlantic, to inform proactive, regionally appropriate management decisions."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Master of Science"]},{"key":"dc:format.medium","label":"Dc Format Medium","values":["ETD"]},{"key":"dc:title","label":"Title","values":["Upstream Population Gradient Drives Freshwater Salinization in the Occoquan Watershed"]}]}],"canonical_facts":{"dc:contributor.committeechair":["Grant, Stanley"],"dc:contributor.committeemember":["Rippy, Megan A.","Saksena, Siddharth"],"dc:contributor.department":["Environmental Science and Engineering"],"dc:creator":["Stacy, Melissa Renee"],"dc:date.accessioned":["2023-08-29T08:00:19Z"],"dc:date.available":["2023-08-29T08:00:19Z"],"dc:date.issued":["2023-08-28"],"dc:description.abstract":["Increased salinization of inland freshwater resources is present on a global scale, but is pro- gressing rapidly in the densely populated Mid-Atlantic United States. This phenomenon threatens aquatic health, ecosystem services and functionality, and can alter the percep- tion of potable drinking water. The Occoquan watershed, located in Northern Virginia has experienced rapid urbanization across recent decades and is now confronted with rising salinization. Various stakeholders in the area have focused efforts to quantify the drivers of salinization in order to take corrective action to preserve this resource. To aid these efforts, urbanization's relationship with in-stream salinity was analyzed, where its exerted influence was found to be dependent upon overland hydrologic flowpaths which connect urban areas to stream networks. The analysis was then broadened to Multiple Linear Regression models of urban and climatological drivers to statistically quantify each driver's relative influence on in-stream salinity. The models demonstrated that urbanization is the primary driver, where rainfall and roadway deicer application were also found to be significant. The model was then used to predict the magnitude of salinization in the Occoquan watershed to a time horizon of 2040 based on expected population growth as well as two anticipated climate scenarios. Finally, the analytical framework produced in this research was generated with scalability in mind, such that it can potentially be utilized as a watershed-scale screening tool accross the Mid-Atlantic, to inform proactive, regionally appropriate management decisions."],"dc:description.abstractgeneral":["Increased salinization of inland freshwater resources is present on a global scale, but is progressing rapidly in the densely populated Mid-Atlantic United States. Driven by the engineered systems that define our modern world, this phenomenon threatens aquatic health, ecosystem services and functionality, and can alter the perception of potable drinking water. The Occoquan watershed, located in Northern Virginia has experienced rapid urbanization across recent decades and is now confronted with rising salinization. Various stakeholders in the area have focused efforts to quantify the drivers of salinization in order to take corrective action to preserve this resource. The analyses completed in this body of work act to model and statistically analyze the drivers which foster salinization in the Occoquan. The analyses demonstrated that while climatological factors drive salinity in the Occoquan, urbanization is the primary driver, where its exerted influence is dependent upon overland hydrologic flowpaths which connect urban areas to stream networks. Further analyses were completed to project salinization to a time horizon of 2040 based on expected population growth as well as two anticipated climate scenarios to predict the magnitude of salinization in the Occoquan watershed in decades to come. These results indicated that anticipated levels of in-stream salinity will increase across most sampling stations in coming years. Finally, the analytical framework produced in this research was generated with scalability in mind, such that it can potentially be utilized as a watershed-scale screening tool accross the Mid-Atlantic, to inform proactive, regionally appropriate management decisions."],"dc:description.degree":["Master of Science"],"dc:format.medium":["ETD"],"dc:identifier.other":["vt_gsexam:38414"],"dc:identifier.uri":["http://hdl.handle.net/10919/116145"],"dc:language.iso":["en"],"dc:publisher":["Virginia Tech"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:subject":["Occoquan","freshwater salinity","urbanization","ecosystem health","human health"],"dc:title":["Upstream Population Gradient Drives Freshwater Salinization in the Occoquan Watershed"],"dc:type":["Thesis"],"thesis:degree_discipline":["Environmental Engineering"],"thesis:degree_level":["masters"],"thesis:degree_name":["Master of Science"],"thesis:institution_name":["Virginia Polytechnic Institute and State University"]},"updated_at":"2026-07-22T22:20:43Z"}