Rivers and their surrounding riparian and subsurface ecosystems, known as river corridors, are important landscape features that provide a myriad of ecological and societal benefits. While the importance of riverine flooding has been widely acknowledged and extensively studied, very little research has been conducted on the interactions between river channels and their adjacent floodplains. The importance of this hydrologic connectivity between rivers and floodplains has been emphasized in recent decades and now ecological engineering techniques such as stream restoration are often utilized to restore connectivity between streams and their riparian ecosystems. Despite its ubiquity in practice, there are still many basic components of river-floodplain connectivity that are not well understood. Furthermore, a lack of cost-effective monitoring techniques makes sustainable management of river corridors quite challenging. Thus, the overall goals of my dissertation were: 1) develop user-friendly river corridor monitoring techniques utilizing cost-effective approaches such as time-lapse digital imagery and satellite remote sensing and 2) identify the effects of anthropogenic activities on river corridor hydrologic and biogeochemical processes that occur at varying spatial and temporal scales during flood events. These goals were addressed through five independent studies that span spatiotemporal scales. The five studies utilized a combination of novel remote sensing, hydrologic/hydraulic modeling, and high frequency spatial sampling techniques to analyze river corridor dynamics. Results highlight that digital imagery and satellite remote sensing can be effective tools for monitoring river corridors in data scare regions. Additionally, impounding streams and river corridors alters floodplain connectivity and biogeochemical processing of reactive solutes such as nitrogen and phosphorus. Findings from this work highlight the important role that spatial and temporal scale plays in river corridor dynamics. Overall, this research provides new analytical techniques and findings that can be used to effectively monitor and manage river corridors. / PHD / Rivers are important landscape features that provide basic societal needs such as drinking water, water for agricultural irrigation, and hydroelectric energy. Engineers have traditionally sought to manage rivers for these purposes while also minimizing flooding. However, flooding actually provides a number of environmental benefits such as increased aquatic biodiversity and removal of excess sediment and pollutants from rivers. This notion of environmentally friendly flooding is a relatively new concept and much is still unknown about how these processes differ at varying scales. Additionally, there is currently a lack of techniques for monitoring such processes primarily due to the cost required for equipment and labor. Therefore, the goals of this dissertation were twofold: 1) develop cost-effective and user-friendly monitoring techniques that can be used to study river flooding dynamics and 2) examine the impacts of river flooding dynamics at three different spatial scales ranging from a small stream to a large watershed. This was accomplished through five separate case studies that examine rivers and watersheds of varying sizes at varying time scales. The studies utilized several emerging technologies that required a combination of field monitoring, computer simulations of flood dynamics, and satellite imagery to gain a better understanding of river flood hydrology and water quality. A key finding was the important role that scale plays in both spatial and temporal domains. Utilizing varying spatial and temporal scales allowed for identification of different processes that occur across a range of river and watershed sizes. Overall, this work can be used to better inform future river management and restoration decisions.
| Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/94643 |
| Date | 26 April 2018 |
| Creators | Keys, Tyler Adam |
| Contributors | Biological Systems Engineering, Scott, Durelle T., Hester, Erich T., Burgholzer, Robert William, Sample, David J. |
| Publisher | Virginia Tech |
| Source Sets | Virginia Tech Theses and Dissertation |
| Detected Language | English |
| Type | Dissertation |
| Format | ETD, application/pdf |
| Rights | In Copyright, http://rightsstatements.org/vocab/InC/1.0/ |
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