Digital Commons Network^™

Development And Evaluation Of Seasonal, Continental-Scale Streamflow Forecasts, Elissa Marie Yeates

Theses and Dissertations

Methods of forecasting streamflow using atmospheric ensembles and hydrologic routing have greatly improved over the past decades. These forecasts anticipate the timing and magnitude of streamflow peaks, enabling early warning of floods. Recent advances in atmospheric modeling have enabled production of forecasts months ahead, which are less precise but give a useful sense of trends.

The purpose of this study is to produce and evaluate a seasonal streamflow forecast model using a Muskingum routing hydrologic model coupled with runoff from a land surface model, and atmospheric input from a medium-term atmospheric and precipitation model. To evaluate the skill of the …

A Citizen-Science Approach For Urban Flood Risk Analysis Using Data Science And Machine Learning, Candace Agonafir

Dissertations and Theses

Street flooding is problematic in urban areas, where impervious surfaces, such as concrete, brick, and asphalt prevail, impeding the infiltration of water into the ground. During rain events, water ponds and rise to levels that cause considerable economic damage and physical harm. The main goal of this dissertation is to develop novel approaches toward the comprehension of urban flood risk using data science techniques on crowd-sourced data. This is accomplished by developing a series of data-driven models to identify flood factors of significance and localized areas of flood vulnerability in New York City (NYC). First, the infrastructural (catch basin clogs, …

Effects Of Historical Land-Use Change On Surface Runoff And Flooding In The Amite River Basin, Louisiana, Usa Using Coupled 1d/2d Hec-Ras–Hec-Hms Hydrological Modeling, Alexandre G. H. Cowles

LSU Master's Theses

The Amite River Basin is a largely rural watershed spanning parts of four counties in southern Mississippi and seven parishes in southeast Louisiana, with basinwide imperviousness increasing from 0.82% in 1938 to 3.85% in 2016. The Basin has been the subject of significant research interest since catastrophic flooding in 2016 caused 13 deaths and widespread damages. Rapid development in recent decades has led to an expansion of impervious surfaces in Baton Rouge and surrounding areas, encroaching on floodplains and wetlands. At the basin scale, differences in flooding due to impervious cover changes were found to be somewhat limited, particularly along …

Understanding The Effect Of Climate And Hydrometeorological Extremes On Natural And Human-Induced Hydrosystems, Jeongwoo Hwang

Dissertations and Theses

The contemporary hydrosystems of the United States involve a complex combination of natural and modified basins in the presence of changing climate and anthropogenic impacts. An enhanced understanding of the interdependence between climate forcings, human-induced interventions, and water balance in both natural and modified basins are essential for developing reliable and resilient hydrosystems and for better water resources management. In response, this dissertation focuses on investigating the hydroclimatology of natural and modified basins across the contiguous United States. It has three research objectives: (1) to explain flow alterations due to anthropogenic activities, especially dam operations, in modified basins and understand …

Physical And Biological Factors Controlling The Fate Of Nitrate In A Louisiana Coastal Deltaic Floodplain, Alexandra Christensen

LSU Doctoral Dissertations

The Mississippi River Delta is threatened by a growing pressure to support large human populations in the United States both with food production, navigation systems, and urban development in the Mississippi River Basin. Nitrate-nitrogen load in the Mississippi River, up to 100 Tg N yr^-1 from agricultural and urban runoff, leads to phytoplankton blooms and hypoxia across the Louisiana continental shelf, creating dead zones of low dissolved oxygen threatening a significant commercial fishery. Along the coast and river corridors, floodplain ecosystems have the capacity to retain and remove nitrate. This dissertation explores the role of productive, actively growing coastal …

Probabilistic Approach To Water, Sediment, And Nutrient Connectivity For Advancing Watershed Modelling, David Tyler Mahoney

Theses and Dissertations--Civil Engineering

The goal of this dissertation is to represent the spatial and temporal domains of water, sediment, and nutrient flux and pathways within fluvial and watershed settings. To complete this goal, we integrate connectivity theory into watershed model structures to simulate water, sediment, and nutrient movement at the fundamental unit they occur. Fluvial-based sediment and nutrient flux is an important driver of global sediment and nutrient budgets, and the quantification of which serves as an ongoing challenge to limnologists, engineers, and watershed managers. Watershed models have been richly developed over the past century, but are currently restrained by problems related to …

Assessing Simulated Transmissivity In Numerical Flow Models Of Complex Hydrogeology, Afan Tarar

UNLV Theses, Dissertations, Professional Papers, and Capstones

Accurately extracting a meaningful transmissivity, a target value within one order of magnitude of field estimates, in numerical models poses a significant challenge when modeling complex groundwater systems. Aquifer transmissivity is directly proportional to the aquifer thickness and the estimated aquifer hydraulic conductivity. In complex geologic conditions (especially in fractured systems) with multiple heterogeneous and anisotropic hydrogeologic units, transmissivity can vary over several orders of magnitude.

To extract a meaningful value of transmissivity from a numerical model, a simple five-layer MODFLOW model was constructed. Each layer in the model was assigned a fixed hydraulic conductivity and thickness. The model simulates …

Hydroclimate Drivers And Atmospheric Dynamics Of Floods, Nasser Najibi

Dissertations and Theses

Our preliminary survey showed that most of the recent flood-related studies did not formally explain the physical mechanisms of long-duration and large-peak flood events that can evoke substantial damages to properties and infrastructure systems. These studies also fell short of fully assessing the interactions of coupled ocean-atmosphere and land dynamics which are capable of forcing substantial changes to the flood attributes by governing the exceeding surface flow regimes and moisture source-sink relationships at the spatiotemporal scales important for risk management. This dissertation advances the understanding of the variability in flood duration, peak, volume, and timing at the regional to the …

Evaluation Of Low-Cost Low Impact Development Practices In Southwest Florida For The Control Of Urban Runoff, Laura Kathren Rankin

USF Tampa Graduate Theses and Dissertations

Stormwater management is required due to development and alteration of the natural environment. It is heavily regulated in Florida and at the national level. Over the last two decades, Low Impact Development (LID) has been promoted as a sustainable and environmentally friendly method of controlling urban runoff. Case studies, provided in Chapter 2, show that LIDs can restore watershed hydrology by balancing the water budget. The difference in runoff between pre-development and post-development appears to increase with soil perviousness. However, the potential for mitigating the impacts of urbanization through runoff reduction is also greater for pervious, sandy soils that dominate …

Systematic Analysis Of Drainage Events In Free Draining And Managed Subsurface Drainage Systems, Guy Bou Lahdou

Open Access Theses

Understanding the hydrologic controls that regulate outflow from free and managed subsurface drainage systems during drainage events can offer improved insight on the overall functioning and effectiveness of the systems so that they can be better managed or retrofitted to increase their environmental benefits. This study used drainage, precipitation, water table, and soil moisture data from a monitoring site located in east central Indiana to investigate the event hydrology of 22 drainage events in free and managed subsurface drainage systems. Relationships between event drainage volume, drain flow hydrograph metrics, column soil moisture, water table depth, and precipitation characteristics were explored …

Long-Term Evaluation Of Norris Reservoir Operation Under Climate Change, Joseph Patton Rungee Ii

Masters Theses

This study aimed to address the potential long-term effects of future climate change on the Tennessee Valley Authority’s (TVA’s) operation policy for Norris Reservoir. The Community Earth System Model 1.0 (CESM1.0), a general circulation model (GCM) accessible through the Intergovernmental Panel on Climate Change’s (IPCC’s) Coupled Model Intercomparison Project Phase 5 (CMIP5), with the Representative Concentration Pathway 4.5 (RCP4.5) was used to obtain projected precipitation and temperature data for three future climate scenarios, 2030’s, 2050’s, and 2070’s. Three hydrologic models were individually calibrated on 30 years of observed runoff data and combined utilizing linear programming to consider the strengths of …

An Investigation Into The Water Budget And The Management Of The Snake River System, John Whitney Hildreth

Boise State University Theses and Dissertations

Future climate change poses a major conceptual challenge to the availability of water resources due to the uncertainty involved with changes to the hydrologic cycle. Over the past decades, observed warming temperatures across the Western United Sates have shown significant impacts on river basin scale hydrology. This research uses physically based modeling tools to assess the hydrologic impacts of climate change in the Snake River Basin. Physically based hydrologic modeling studies of future climate do not typically take into account interactions between groundwater and surface water. To account for these interactions, the Variable Infiltration Capacity model is coupled with the …

Hydraulic Impact Of Porosity Distribution And Hydrologic Characterization Of Porous Pavements, William Martin

All Dissertations

This research focused on the hydrologic characterization of porous pavement and pavement properties that can affect its hydraulic behavior. The first of these properties investigated was the presence of a vertical porosity distribution which can significantly impact the infiltration rate. A method utilizing image analysis was tested and experimentally verified. The representative elemental area (REA) was needed for this imaging method and was found to be 83.9 cm2 (13 in2). To convert the porosity distribution into a permeability distribution the relationship between porosity and permeability was found using homogenous samples. From the resulting permeability distribution an effective permeability was found …

Hydrologic Characterization Of A Rain Garden Mitigating Stormwater Runoff From A Commercial Area, John T. Mcmaine

Theses and Dissertations--Biosystems and Agricultural Engineering

Impervious surfaces such as roads, sidewalks, and roofs increase the volume of runoff generated in a watershed. Traditional stormwater management techniques emphasize conveyance of runoff away from impervious surfaces in order to reduce flooding. Rain gardens are becoming popular as a different means to manage stormwater in such a way that runoff is captured and infiltrated onsite rather than conveyed offsite. A stormwater management system consisting of a rainwater harvest system, rain garden, and infiltration chamber was built at the Coca-Cola Refreshments USA, Inc. distribution center in Lexington, Kentucky during the fall of 2011. Precipitation, inflow, and water level were …

Watershed-Scale Hybrid Stochastic-Deterministic Modeling Framework And Diffused Sources Superpositioning, Ruby Juvah Damalie

Civil & Environmental Engineering Theses & Dissertations

Predicting hydrologic system behavior is imperative to planning and management of water resources. The study developed an integrated hybrid stochastic and deterministic framework to improve prediction accuracy for overland flow and diffused sources in a watershed. The methodology includes sampling input parameters at system level and contribution of nonpoint source from hydrologically disconnected areas (heretofore referred to as system-level approach and superpositioning respectively). System-level approach includes the integration of a topography-based sampling grid generalized linear model developed by the study and Monte Carlo methods. The superpositioning method adopts in-stream water quality equation for overland flow pollution estimation.

The system-level approach …

Hydrologic Reconstructions Using Dendroclimatology, Climate Signals, And Pacific Ocean Sea Surface Temperature Variability, Sallyrose Anderson

Doctoral Dissertations

The Colorado River provides water to over 25 million people. Given the importance of this water supply, it is critical to understand the hydrologic variables in the Colorado River Basin. In this dissertation, I reconstructed hydrologic conditions (soil moisture, snowpack) in the Upper Colorado River Basin (UCRB) and examined different factors that influence water supply in the region (climate oscillations, oceanic-atmospheric variability).

Firstly, I reconstructed soil moisture in the UCRB. Principal components analysis (PCA) and k-Nearest Neighbor (k-NN) techniques were used to regionalize the gridded data. Correlated tree-ring chronologies (TRCs) were used as predictor variables in stepwise linear regression (SLR) …

Integrating Surface And Sub Surface Flow Models Of Different Spatial And Temporal Scales Using Potential Coupling Interfaces, Alphonce Chenjerayi Guzha

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The main objective of this research was to develop and utilize a coupled surface water groundwater model to simulate hydrological responses of watersheds. This was achieved by coupling the U.S. Geological Survey (USGS) groundwater flow model, MODFLOW, and the rainfall runoff model, TOPMODEL, in one case study and coupling MODFLOW with a networked version of TOPMODEL called TOPNET in another case study. The model coupling was achieved using the InCouple approach, which utilizes Potential Coupling Interfaces (PCIs) that are abstractions from model flow diagrams that expose only those aspects of a model relevant to coupling. Coupling the rainfall-runoff models to …

Optimal Design Of Pump And Treat Remediation Systems : Treatment Modeling, Source Modeling And Time As A Decision Variable, Karen L. Endres

Dissertations, Master's Theses and Master's Reports - Open

Groundwater optimization and simulation is a maturing science. Research work contained in this thesis extends into areas that have not been fully explored. The incorporation of source and treatment systems selection and design produces information to help decision makers. Further insight is gained by evaluating some of the requirements and standards enforced by regulations such as, remediation time.

The technical aspects of a remediation system are set by the physical properties and the regulatory constraints enforced. As an example, the addition of a realistic treatment system gives more accurate cost estimates, but the pump and treat (PAT) systems parameters do …

A Hydrological Characterization Of A Zero-Order Basin In Volcanic Hillslope Terrain, Neil A. Mock

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Hydrologists have displayed a renewed effort towards understanding the complexity of runoff generation and its association with basin structure. Basin structure is defined as the complex geomorphological, vegetation, and soil characteristics that make up and distinguish the physical nature of a drainage basin. Zero-order basins are an integral part of watershed structure because they furnish the capacity to store and transmit snowmelt and rainfall. By definition, zero-order basins are sub-basins which are depressions in the surf ace and shallow bedrock topography. This study involves a space time characterization of a zero-order basin in fractured media located in southwest Idaho.

The …