- Three-Dimensional Modeling of River Flows Under Extreme Weather Scenarios
- Low-cost Real-time Streamflow Network for Falling Water River Watershed
- Rethinking Bank Stabilization in Tennessee to Develop a Classification Protocol for Agricultural and Urbanized Systems
Project Number: 2018TN136B
Title: Three-Dimensional Modeling of River Flows Under Extreme Weather Scenarios
Team: Jejal Reddy Bathi, Dept. of Civil & Chemical Engineering; and Kidambi Sreenivas, Dept. of Mechanical Engineering, University of Tennessee at Chattanooga
The proposed research is the development and application of a 3D hydraulic and water quality model using the tool named Environmental Fluid Dynamics Code (EFDC) for City of Chattanooga (the City) urban portion of Tennessee River below Chickamauga Reservoir, TN. The developed model will demonstrate the usefulness of three-dimensional simulations for watershed management under low flow (drought) and high flow (flooding) conditions. The river historic flows will be evaluated to determine flows and river levels for extremely low (low 5%) and extremely high (high 5%) flow periods and the model will be calibrated for these extreme conditions. The calibrated model will be used to simulate water quality under varied scenarios of extreme flows so that the pollutant fate and transport, reliability and availability of flows for water supply will be evaluated. More specifically, fate and transport of pollutants entering the river system because of persistent combined sewer overflows from the City areas will be assessed in order to estimate the spatial and temporal variability of river pollution and help assist to better manage drinking water utility intake operations, which is within the proposed model domain. In addition, understanding river flows, which will be achieved by proposed model, is critical for Tennessee Valley Authority (TVA) to manage releases from Chickamauga Reservoir, which is at immediate upstream of the proposed model boundary. As well, as part of this study, potential impact on identified critical infrastructure will be determined. For example, simulated critical velocity and bed scour at the bridge piers will be used to determine stress and hence the potential damage to the bridge stability. In addition, flood inundation of the critical infrastructure along the river banks will be evaluated using model simulated flood elevation under extreme high flow conditions. Overall, the proposed research is a demonstration study that will showcase usefulness and approach of using 3D computer models to help prepare river watershed management to prepare for possible extreme conditions that would cause devastating damage to critical infrastructure, environment and public health, if not prepared in advance.
Project Number: 2018TN135B
Title:Low-cost Real-time Streamflow Network for Falling Water River Watershed
PI: Alfred Kalyanapu; Dept. of Civil & Environmental Engineering, Tennessee Tech University
Streamflow monitoring in the United States (US) is a cost-intensive venture, and usually performed by government agencies like the US Geological Survey (USGS). With reduced resources across the federal agencies towards environmental monitoring, agencies and stakeholders are challenged to respond with cross-cutting, collaborative and low-cost alternatives for streamflow monitoring. One such alternative is using low-cost environmental sensors and developing a real-time sensor network using IoT (Internet of Things) devices. With this technology, smaller watersheds (e.g., HUC-8 and HUC-10 level) can be equipped with lost-cost sensors at many locations and a clear picture of hydrological response can be achieved. Therefore, the objective of the proposed project is to develop a low-cost, real-time streamflow network for the Falling Water River Watershed in middle Tennessee region. To achieve the project objectives, the following three tasks are proposed: (i)- Assemble a low-cost, real-time enabled water level sensor, (ii)- Field-testing of the sensors, and (iii)- Installation of the sensors and sensor network. The Falling Water River Watershed, which covers Putnam, White and Dekalb counties, is home to the City of Cookeville, the urban center in the Upper Cumberland Plateau. With projected future growth, its stakeholders including the Tennessee Division of Environment and Conservation, United States Geological Survey, Tennessee Department of Transportation, Burgess Falls State Park, City of Cookeville, and Tennessee Clean Water Network, formed a collaborative partnership to develop a Falling Water River watershed plan. A crucial component of this plan is a continuous streamflow data in the watershed, which currently has one USGS station with a one-year data record. Therefore, the proposed project will lead a dense sensor network across the watershed, and over time enable the stakeholders to have a spatially variable hydrological response of the Falling Water River Watershed.
Project Number: 2018TN134B
Title: Rethinking Bank Stabilization in Tennessee to Develop a Classification Protocol for Agricultural and Urbanized Systems
Team: Thanos Papanicolaou, John Schwartz, and Chris Wilson, Dept. of Civil & Environmental Engineering, University of Tennessee, Knoxville
Bank stabilization in Tennessee is a concern for landowners, city managers, governmental agencies, and engineering consulting firms. Although many bank stabilization methods currently exist, the decision-making process for selecting the most optimal method has not been addressed fully due to the complex interactions between streams and uplands that are continuously changing under human modifications and climate non-stationarity. There is a critical need in Tennessee to develop a classification protocol that is science-based for selecting the most suitable bank stabilization method depending on site characteristics. This classification protocol will identify the stabilization methods that can work under the range of stream power values for a given channel reach, as well as provide guidelines to state agencies regarding the selection and placement of the possible mitigation strategies. It will also suggest the most optimal method, among those that may work, based on soil type, vegetation, environmental needs, failure risk, cost, and human disturbance, such as intense agriculture or increased urbanization. In this study, we will take the first steps for developing a classification protocol for Tennessee by conducting an extensive literature review. The review will focus on not only the current geomorphic rapid channel assessments and available bank stabilization approaches, but also the expected ranges of stream flow conditions where these methods will work. In addition, the review will be conducted to identify potential criteria that can be used to assess bank stability. This information will go into developing a flow chart that can be used to select certain practices for a particular reach. This project innovatively uses improved assessment and evaluation techniques coupled with more quantitative parameters like stream power to identify if bank bio-based stabilization techniques and stream restoration designs can be incorporated. As a result, this classification scheme for the state of Tennessee suggests bank stabilization methods within an ecological and geomorphic context that will result in improved ecological outcomes and at a lower cost.