Hydrology Commons^™

Decomposing A Watershed’S Nitrate Signal Using Spatial Sampling And Continuous Sensor Data, Evan Clare

Theses and Dissertations--Civil Engineering

Watershed features, physiographic setting, geology, climate, and hydrologic processes combine to produce a time-variant nutrient concentration signal at the watershed outlet. Anthropogenic influences, such as increased agricultural pressures and urbanization, have increased overall nutrient loadings delivered to the fluvial network. The impact of such increased nutrient loadings on Kentucky’s drinking water remains a potential threat to the region.

By coupling spatial sampling of nitrate concentrations in surface water with contemporary nutrient and water quality sensor technology, a decomposition of the Upper South Elkhorn watershed’s nitrate signal and an estimation of source timing and loading in the watershed was completed. The …

Variability In Groundwater Flow And Chemistry In The Houzhai Karst Basin, Guizhou Province, China, Joshua M. Barna

Theses and Dissertations--Earth and Environmental Sciences

Understanding how karst aquifers store and transmit water and contaminants is an ongoing problem in hydrogeology. Flowpath and recharge heterogeneity contribute to the complexity of these systems. This thesis explores karst-conduit connectivity and water chemistry variability in the Houzhai catchment in Guizhou province, China. Artificial tracer tests were conducted during both the monsoon and dry seasons to understand temporal variability in connectivity and water velocity between karst features. Multiple flowpaths through the catchment are activated during the monsoon season and partially abandoned during the dry season. Additionally, gradient reversals during monsoonal high-flow events and as a result of pumping can …

Rethinking Karst Hazard Assessment In Kentucky, William P. Pierskalla Jr.

Theses and Dissertations--Earth and Environmental Sciences

Current karst hazard maps in Kentucky reflect the general lithology of the state and ignore or significantly reduce the impact of the actual sinkholes present within these areas. These maps rely on equal weighting, by area, of the Karst Potential Index (KPI) map and the sinkhole inventory map. The KPI is based on a 1:500,000 geologic map and less than 500 data points of carbonate rocks. The sinkhole inventory is derived from topographic maps updated in the 1970s with approximately 10-foot resolution. This method gives a preferential weighting of the KPI over the sinkhole data. Consequently, the current method is …

Temporal And Spatial Variability In Groundwater Flow And Chemistry Along The Cumberland River, Artemus, Kentucky, Amanda Rachelle Sherman

Theses and Dissertations--Earth and Environmental Sciences

Groundwater in the Kentucky Appalachian region is constrained by physiography and lithology. Lithostratigraphy, groundwater flow, and chemistry were delineated in the alluvial aquifer along the Cumberland River at H.L. Disney Training Center. To assess groundwater-river interactions and water quality, 11 monitoring wells were installed and sampled quarterly, plus the river and an existing bedrock well. Analytical results were evaluated for temporal and spatial trends. Collected soil cores were analyzed for bulk chemistry and grain size. Solute speciation and saturation indices were calculated and hydraulic conductivity estimated from grain-size analyses. Pumping and slug tests were performed to estimate hydraulic conductivity and …

Electrical Conductivity And Resistivity Study Of Heterogeneous Sediment In Inwood Hill Park, Manhattan, Ny, Rea A. Khaleda

Dissertations and Theses

The area near the inlet of Spuyten Duyvil Creek in Inwood Hill Park in New York City exhibits complex hydrological processes. The inlet is a tidal flat, which contains brackish water; a mixture of saltwater and freshwater. The area was modified by man, built on a shell bed and contains heterogeneous sediment. One field adjacent to the inlet contains several small sinkholes. Electrical resistivity and ground conductivity techniques were used in order to get an understanding of the hydrological processes of this field. It was hypothesized that the formation of the sinkholes is due to the tidal forcing of the …

Application Of A Distributed Hydrologic Model For The Analysis Of Land Use Change In Kedougou, Senegal, Francisco Perez

Dissertations, Master's Theses and Master's Reports

West Africa has experienced extensive land use/land cover (LULC) change since the Sahel drought of the 1970s and 80s. Demographic changes, rapid urbanization, and other anthropogenic impacts on land cover in West Africa have potentially altered hydrological regimes. This work was undertaken while I served as a Peace Corps Volunteer in the Kedougou region of Senegal, an area that has experienced significant and rapid infrastructural improvements and urbanization since the early 2000s. The Gambia River flows near Kedougou, where flooding is an extensive problem, making access and livelihood practices difficult during the rainy season. Changes in climate and land use …

Delivering Sustained, Coordinated, And Integrated Observations Of The Southern Ocean For Global Impact, Louise Newman, Petra Heil, Rowan Tebilco, Katsuro Katsumata, Andrew Constable, Esmee Van Wijk, Karen Assmann, Joana Beja, Phillippa Bricher, Richard Coleman, Daniel Costa, Steve Diggs, Riccardo Farneti, Sarah Fawcett, Sarah T. Gille, Katharine R. Hendry, Sian Henly, Eileen Hofmann, Ted Maksym, Matthew Mazloff, Andrew Meijers, Michael M. Meredith, Sebastien Moreau, Burcu Ozsoy, Robin Robertson, Irene Schloss, Oscar Schofield, Jiuxin Shi, Elisabeth Sikes, Inga J. Smith, Sebastiaan Swart, Anna Wahlin, Guy Williams, Michael J. M. Williams, Laura Herraiz-Borreguero, Stefan Kern, Jan Lieser, Robert A. Massom, Jessica Melbourne-Thomas, Patricia Miloslavich, Gunnar Spreen

CCPO Publications

The Southern Ocean is disproportionately important in its effect on the Earth system, impacting climatic, biogeochemical, and ecological systems, which makes recent observed changes to this system cause for global concern. The enhanced understanding and improvements in predictive skill needed for understanding and projecting future states of the Southern Ocean require sustained observations. Over the last decade, the Southern Ocean Observing System (SOOS) has established networks for enhancing regional coordination and research community groups to advance development of observing system capabilities. These networks support delivery of the SOOS 20-year vision, which is to develop a circumpolar system that ensures time …

A Dual State Hierarchical Ensemble Kalman Filter Algorithm, William J. Cook, Jesse Johnson, Marko Maneta, Doug Brinkerhoff

Graduate Student Theses, Dissertations, & Professional Papers

Dynamic models that simulate processes across large geographic locations, such as hydrologic models, are often informed by empirical parameters that are distributed across a geographical area and segmented by geological features such as watersheds. These parameters may be referred to as spatially distributed parameters. Spatially distributed parameters are frequently spatially correlated and any techniques utilized in their calibration ideally incorporate existing spatial hierarchical relationships into their structure. In this paper, a parameter estimation method based on the Dual State Ensemble Kalman Filter called the Dual State Hierarchical Ensemble Kalman Filter (DSHEnKF) is presented. This modified filter is innovative in that …

Utilization Of Various Methods And A Landsat Ndvi/Google Earth Engine Product For Classifying Irrigated Land Cover, Andrew Nemecek

Graduate Student Theses, Dissertations, & Professional Papers

Methods for classifying irrigated land cover are often complex and not quickly reproducible. Further, moderate resolution time-series datasets have been consistently utilized to produce irrigated land cover products over the past decade, and the body of irrigation classification literature contains no examples of subclassification of irrigated land cover by irrigation method. Creation of geospatial irrigated land cover products with higher resolution datasets could improve reliability, and subclassification of irrigation by method could provide better information for hydrologists and climatologists attempting to model the role of irrigation in the surface-ground water cycle and the water-energy balance. This study summarizes a simple, …

Ephemeral Gully Erosion Modeling And Surveying With Close-Range Digital Photogrammetry, M. A. Islam, C. Weerasekara, Y. Zhou, A. Y. Shesukov

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Exploring The Northwest Margin Of The High Plains Aquifer: Structure, Depositional History And Hydrogeology, Nebraska Geological Society Field Trip, Doug Hallum, Dennis O. Terry, Jr., Michael Leite, Jennifer Balmat

Conservation and Survey Division: Faculty and Staff Publications

The northwest portion of the High Plains Aquifer in Nebraska corresponds with the western Sandhills, Box Butte, Sioux and Dawes County tablelands, and the Nebraska Pine Ridge in northwest Nebraska. This field excursion will travel beyond the margins of the High Plains aquifer into the White River valley and onto the Oglala National Grasslands. These areas are not only rich in natural resources, but rich in history as well. While this excursion will explore earth history, depositional environments and a portion of the High Plains Aquifer, the authors encourage all attendees to take additional time to explore the cultural, military …

Biogeochemical And Hydrological Impacts Of A Low-Severity Wildfire In The Wetland-Dominated Zone Of Discontinuous Permafrost, Caren J. Ackley

Theses and Dissertations (Comprehensive)

Northern regions are experiencing rapid climate warming. As these regions warm, the occurrences of naturally ignited wildfires are increasing in frequency, severity and area burned, calling for a more thorough understanding of post-fire eco-hydrological impacts. Changes in runoff chemistry, and soil moisture and thermal regimes, have been attributed to the significant loss of organic matter (OM) and exposure of deeper soils, leading to enhanced permafrost degradation, ground surface subsidence and the conversion of peat landscapes from long-term C sinks to sources. However, low-severity wildfires often result in minor OM loss. Due to the significant and immediate threats posed to the …

Development And Application Of Hydrological And Limnological Monitoring In Lake-Rich Landscapes Of Canada’S Subarctic National Parks, Hilary Emma White

Theses and Dissertations (Comprehensive)

Arctic and subarctic environments are being adversely influenced by human-caused climate change across our entire planet. Canada’s northern freshwater ecosystems are influenced by a variety of environmental stressors and are particularly sensitive to climate change, since small shifts in climate have the potential to substantially alter their hydrological, limnological, and biogeochemical conditions. Some other indirect effects on northern freshwater landscapes are the expansion of vegetation as well as changes in wildlife and waterfowl populations and distribution. It is, therefore, critical to understand the observed and predicted influences of climate change and other environmental stressors on these northern freshwater environments dominant …

Snowmelt Detection On Alpine Glaciers Using Synthetic Aperture Radar Time Series, Corey Scher

Dissertations and Theses

Hindu Kush Himalayan (HKH) glaciers serve as some of the most sensitive indicators of changes in global climate. These glaciers shape the hydrologic dynamics of river systems supplying freshwater to over 2 billion people throughout Asia and regulate the geochemistry of sensitive aquatic alpine ecosystems. As snowmelt onsets sooner, lasts longer, and snowfields retreat due to increases in global temperature, the hydrologic dynamics of catchments draining HKH threaten to change the availability of surface freshwater resources for nearly one fifth of the global population, disturb sensitive aquatic habitat, and precipitate hazards associated with glacier wasting. Informed planning and decision-making around …

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 …

Hydrogeochemical Characterization Of Yalahau Region, Mexico, Jessica Leann Mckay

Graduate Research Theses & Dissertations

The Yalahau Region, located in the northeastern portion of the Yucatán Peninsula, hosts a series of elongated depressions trending north/south in the direction of Isla Holbox, identified as the Holbox Fracture Zone. Previous studies have explored the geomorphology and various hydrologic characteristics of the Yucatán Peninsula; however, there is a paucity of data concerning the interior region where the fractures are located. Strontium isotope and major ion geochemistry data of the surface water and groundwater of this region serves as a hydrogeochemical fingerprint, aiding to constrain the hydrological boundaries, determining flow paths, and characterizing hydrogeochemical processes that impact the composition …

Automatic Detection And Analysis Of Rip Currents At Haeundae Beach Using X-Band Marine Radar, Chanyeong Oh, Kyungmo Ahn, Se-Hyeon Cheon

OES Faculty Publications

The observation system has been developed to investigate the rip currents at Haeundae beach using Xband marine radar. X-band radar system can observe shape, size, and velocity of rip currents, which is difficult to obtain through field observation by conventional device. Algorithms which automatically detect locations, shapes, and magnitudes of rip currents were developed using time averaged X-band radar sea clutter images. X-band sea clutter images are transformed through 3D FFT into 2D wave number spectrum and frequency spectrum. Rip current velocities were estimated using differences in wave-number spectra and wave frequency spectra due to Doppler shift. The algorithm was …

Cosmic Ray Sensors For The Continuous Measurement Of Arctic Snow Accumulation And Melt, Anton Jitnikovitch

Theses and Dissertations (Comprehensive)

In the Arctic, winter persists for much of the year, resulting in a hydrological system that is primarily regulated by snow and snowmelt runoff, and has important implications on vegetation, animals, and on the thermal regime of the active layer and permafrost. Snow water equivalent (SWE) measurements such as remote sensing techniques provide coarse resolution data, while snow surveys and snow-pits are labour intensive, have limited spatial coverage and do not provide a continuous reading. Over the last few decades, cosmic ray sensors (CRS) have been proposed as a way to provide much improved snow data, but few studies have …

High Resolution Spatial Variability In Spring Snowmelt For An Arctic Shrub-Tundra Watershed, Branden J. Walker, Philip Marsh Dr

Theses and Dissertations (Comprehensive)

Arctic tundra environments are characterized by spatially heterogeneous end-of-winter snow cover because of high winds that erode, transport and deposit snow over the winter. This spatially variable end-of-winter snow cover subsequently influences the spatial and temporal variability of snowmelt and results in a patchy snowcover over the melt period. Documenting changes in both snow cover area (SCA) and snow water equivalent (SWE) during the spring melt is essential for understanding hydrological systems, but the lack of high-resolution SCA and SWE datasets that accurately capture micro-scale changes are not commonly available, and do not exist for the Canadian Arctic. This study …

Carbon Dioxide Measurement In Irish Blanket Peatlands: An Assessment Of Pool-Soil Flux Variability, Mariya Radomski, Alan Gilmer, Vivienne Byers, Eugene Mcgovern

Articles

Peatlands have been recognised as having a significant role in the mediation of atmospheric carbon dioxide (CO2) levels with direct implications for global climate change. Longitudinal in situ measurement systems for CO2 concentrations in blanket peatland ecosystems are difficult to implement where the nature of terrestrial–aquatic connectivity and hydrodynamics have a significant effect on the carbon cycle. The need for greater data on CO2 concentrations and flux monitoring in these settings has been well recognised. However, applying the most appropriate monitoring approach presents a special challenge. This paper sets out the development of a direct method for field based longitudinal …

Modeling The Flow Of Hall Creek, Humboldt County, California Using Visualizing Ecosystem Land Management Assessments (Velma) And Calculating The Channel Forming Flow Using The Effective Discharge Calculation, Ethan A. Luckens

Cal Poly Humboldt theses and projects

Due to wide spread stream degradation across the globe, there is great potential for restoring stream and riverine habitat. Land managers often lack necessary information about the stream discharges of ungauged watersheds. This lack of data makes designing stream restoration projects in ungauged watersheds more difficult. This is especially true when trying to determine the channel-forming flow, the discharge that will support a stable channel geometry. In this study, the channel-forming flow was approximated using effective flow. Effective flow is the level of flow that transports to the greatest amount of sediments. One method for calculating effective flow is to …

Floodplains Provide Important Amphibian Habitat Despite Multiple Ecological Threats, Meredith Holgerson, Adam Duarte, Marc P. Hayes, Michael J. Adams, Julie A. Tyson, Keith A. Douville, Angela L. Strecker

Environmental Science and Management Faculty Publications and Presentations

Floodplain ponds and wetlands are productive and biodiverse ecosystems, yet they face multiple threats including altered hydrology, land use change, and non-native species. Protecting and restoring important floodplain ecosystems requires understanding how organisms use these habitats and respond to altered environmental conditions. We developed Bayesian models to evaluate occupancy of six amphibian species across 103 off-channel aquatic habitats in the Chehalis River floodplain, Washington State, USA. The basin has been altered by changes in land use, reduced river–wetland connections, and the establishment of non-native American bullfrogs (Rana catesbeiana = Lithobates catesbeianus) and centrarchid fishes, all of which we hypothesized could …

Improved Drought Resilience Through Continuous Water Service Monitoring And Specialized Institutions—A Longitudinal Analysis Of Water Service Delivery Across Motorized Boreholes In Northern Kenya, Nick Turman-Bryant, Corey L. Nagel, Lauren Stover, Christian Muragijimana, Evan A. Thomas

Complex Systems Faculty Publications and Presentations

Increasing frequency and severity of drought is driving increased use of groundwater resources in arid regions of Northern Kenya, where approximately 2.5 million people depend on groundwater for personal use, livestock, and limited irrigation. As part of a broader effort to provide more sustainable water, sanitation, and hygiene services in the region, we have collected data related to site functionality and use for approximately 120 motorized boreholes across five counties. Using a multilevel model to account for geospatial and temporal clustering, we found that borehole sites, which counties had identified as strategic assets during drought, ran on average about 1.31 …

Mechanics And Historical Evolution Of Sea Level Blowouts In New York Harbor, Praneeth Gurumurthy, Philip Orton, Stefan A. Talke, Nickitas Georgas, James F. Booth

Civil and Environmental Engineering Faculty Publications and Presentations

Wind-induced sea level blowouts, measured as negative storm surge or extreme low water (ELW), produce public safety hazards and impose economic costs (e.g., to shipping). In this paper, we use a regional hydrodynamic numerical model to test the effect of historical environmental change and the time scale, direction, and magnitude of wind forcing on negative and positive surge events in the New York Harbor (NYH). Environmental sensitivity experiments show that dredging of shipping channels is an important factor affecting blowouts while changing ice cover and removal of other roughness elements are unimportant in NYH. Continuously measured water level records since …

Bigger Tides, Less Flooding: Effects Of Dredging On Barotropic Dynamics In A Highly Modified Estuary, David K. Ralston, Stefan Talke, W. Rockwell Geyer, Hussein A. M. Al-Zubaidi, Christopher K. Sommerfield

Civil and Environmental Engineering Faculty Publications and Presentations

Since the late nineteenth century, channel depths have more than doubled in parts of New York Harbor and the tidal Hudson River, wetlands have been reclaimed and navigational channels widened, and river flow has been regulated. To quantify the effects of these modifications, observations and numerical simulations using historical and modern bathymetry are used to analyze changes in the barotropic dynamics. Model results and water level records for Albany (1868 to present) and New York Harbor (1844 to present) recovered from archives show that the tidal amplitude has more than doubled near the head of tides, whereas increases in the …

Temporal Changes Of Nutrients Within The Lower Grand River Watershed And Selected Sites, Weston Scott Duley

Masters Theses

"This report presents the results of a study carried out in collaboration with the U.S. Geological Survey (USGS) and the Missouri Department of Natural Resources (MDNR) to estimate total nitrogen (TN) and total phosphorus (TP) at five USGS monitoring sites within Lower Grand River Watershed (LGRW) and two monitoring sites on the Missouri River. The objective of this study was to quantify temporal changes in TN and TP concentrations and compare those to best management practices (BMPs).

In this study, the approach to the analysis of long-term surface water-quality data by using Weighted Regressions on Time, Discharge and Seasons models …