Physical Sciences and Mathematics Commons^™

Employing Earth Observations And Artificial Intelligence To Address Key Global Environmental Challenges In Service Of The Sdgs, Wenzhao Li

Computational and Data Sciences (PhD) Dissertations

Earth Observation (EO) data provides the capability to integrate data from multiple sources and helps to produce more relevant, frequent, and accurate information about complex processes. EO, empowered by methodologies from Artificial Intelligence (AI), supports various aspects of the UN’s Sustainable Development Goals (SDGs). This dissertation presents author’s major studies using EO to fill in knowledge gaps and develop methodologies and cloud-based applications in selected SDGs, including SDG 6 (Clean Water and Sanitation), SDG 11 (Sustainable Cities and Communities), SDG 14 (Life below Water) and SDG 15 (Life on Land). For SDG 6, the study focuses on spatiotemporal water recharge …

Wildfire In The West: An Initial Analysis Of Wildfire Impacts On Hydrology And Riverbed Grain Size In Relation To Salmonid Habitat, Natalie J. Gillard

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Historically wildfires have been beneficial to forests, however, human developments have encroached on forests when wildfire was artificially suppressed by federal and state agencies. The area burned by wildfire each year has increased twenty-fold in the past three decades. Large, high severity fires pose increased threats to human and aquatic communities within and downstream of the burned area due to post-wildfire effects on flooding and sedimentation. We need to understand the impacts of wildfires to be able to mitigate their damages and to recognize their potential benefits. This research addresses the questions: 1) Do wildfires impact rural and urban economies …

Estimation Of Evapotranspiration And Other Water Budget Factors At Glacier Creek Preserve, Kian Paul Mcintosh

Theses/Capstones/Creative Projects

A water budget of a watershed consists of the inputs and outputs of water to and from it, including precipitation, change in water storage, surface water flow, and evapotranspiration. Water budget estimates are of high importance as a result of increasing demand due to population growth and other factors. Improving estimate accuracy and precision of evapotranspiration and runoff to streams allows scientists to better determine the true availability of water for human and conservation use. At Glacier Creek Preserve, 6.5% of the incoming precipitation left the preserve as discharge from the stream and 95.9% of the incoming precipitation was lost …

Hydrologic Structure And Function Of Vernal Pools In South Deerfield, Massachusetts, Charlotte Axthelm

Masters Theses

Vernal pools are small, ephemeral wetlands lacking an inlet or outlet. These wetlands, also known as seasonal pools, are found in a wide range of biomes, and their characteristics vary based on location. While the vegetation of western U.S. pools, and amphibians of eastern U.S. pools have been extensively studied, many aspects of vernal pools have not been fully characterized. In particular, although the general seasonal wetting and drying cycle is understood qualitatively, few studies have attempted to quantify the hydrological regime of vernal pools in New England. As water level variation drives many, if not all, of the characteristics …

An Exploration Into The Controls And Extent Of Capillary Rise In Fine-Grained Sand, Neal S. Turluck

Masters Theses

Capillary rise in fine-grained sands is especially important due to the wide distribution of fine-grained sediment throughout the unconsolidated sedimentary layers blanketing the earth. The height to which water rises above the water table in porous media is known as the capillary fringe. Tension pulling on the water molecules from the solid surfaces of pores will cause water to rise in the unconsolidated fine-grained sands until the water reaches equilibrium with the downward force of gravity.

Researching the controls behind capillary rise and being able to predict the extent to which water will rise in fine-grained sand helped provide insight …

Evaluating Sources Of Hydrochemical Variability And Mixing In The Upper Gila River, New Mexico, Pavel Vakhlamov

Earth and Planetary Sciences ETDs

This study of the upper reaches of the Gila River basin in southwestern New Mexico reveals both spatial and seasonal patterns in physical and hydrochemical parameters. Monsoonal precipitation, temporal variability in water chemistry of streams in the upper Gila watershed is significantly impacted by surface runoff due to variability in landscape cover features, as well as surface area of the catchment. However, during base flow regimes spring inputs are the dominant drivers of solute concentrations and chemical variability.

Geothermal sources play a major role in salinization of the southwestern stream systems. Prolonged water/rock interaction combined with high temperature, pressure result …

Evaluating Future Reservoir Storage In The Rio Grande Using Normalized Climate Projections And A Water Balance Model, Nolan T. Townsend

Earth and Planetary Sciences ETDs

We develop and implement new tools for assessing the future of surface water supplies in downstream reaches of the Rio Grande, for which Elephant Butte Reservoir is the major storage reservoir. First, a normalization procedure is developed to adjust natural Rio Grande streamflows simulated by dynamical models in downstream reaches. The normalization accounts for upstream anthropogenic impairments to flow that are not considered in the model, thereby yielding downstream flows closer to observed values and more appropriate for use in assessments of future flows in downstream reaches. The normalization is applied to assess the potential effects of climate change on …

Decadal Changes Of Soil Physiochemical Properties In A Freshwater Wetland After Hydrologic Reconnection, Alina Spera

LSU Master's Theses

Sediment, nutrient deprivation and salt water intrusion, among other factors, are driving widespread organic soil collapse and marsh loss in the Mississippi River Delta. Freshwater diversions were designed to reintroduce Mississippi River water and dissolved nutrients into the adjacent basins to manage salinity and slow land loss by maintaining marsh vegetation and nutrient cycling functions. These diversions are controversial by a few, suggesting that nutrient enrichment without a sediment subsidy can lead to further wetland loss in the receiving basins. In this study, a soil characterization is presented for the receiving marsh of the Davis Pond diversion in 2007, just …

Characterizing The Waters Of 6 Rivers In Upstate New York With A Focus On Physical Hydrology And Controls On Water Quality, Connor Horan

Honors Theses

Rivers are key passageways connecting inland waters to the world’s oceans. They are responsible for the mobilization and transport of nutrients, sediments, and weathered materials. Rivers have been influential in the development of human civilization and are hubs for people and businesses to populate. As our population puts a heavier burden on these waterways, there is a need to better understand the controls on their water quality.

The overarching goal of this research is to improve our understanding of the hydrology and water resources of the Upper Hudson and Mohawk watersheds. This is critical to our understanding of the ecological …

River Hydrology, Morphology, And Dynamics In An Intensively Managed, Transient Landscape, Sara Ann Kelly

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Rivers create beautiful patterns and provide drinking water to millions. However an alarming number of rivers in the US and globally are threatened by excess sediment and nutrients. Agricultural rivers draining erodible soils are particularly vulnerable. Rivers of southern Minnesota provide a unique opportunity to study water and sediment dynamics in a naturally vulnerable system. Sediment reduction strategies are needed to ensure biological integrity and adequate water quality. Here, I address the questions: 1) have climate, land use practices, or both affected streamflows in Midwest agricultural rivers?, 2) which streamflows set the rate of river bluff erosion?, and 3) how …

Rating Curve Development For The Upper James Fork, Lower James Fork And Hinkle Jones Creek In The Upper Poteau River Watershed In Arkansas, Meagan O'Hare

Biological and Agricultural Engineering Undergraduate Honors Theses

Stream discharge is necessary to estimate loads and calibrate and validate watershed models. Access to long-term water quality data and discharge measurements allows for modeling of water quality changes across a watershed over time. However, discharge monitoring stations are often expensive to install and maintain, particularly in small rivers. A more cost-effective method for monitoring streamflow has been implemented in the Upper Poteau River Watershed (UPRW) in Arkansas. This method consists of an SonTek acoustic doppler instrument for measuring storm stream flow, with is combined with manual baseflow discharge measurements. The combined stormflow and baseflow measurements are combined with a …

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 …

Environmental Controls On Dissolved Carbon Export And River Geochemistry - A Case Study In The Mississippi-Atchafalaya System, Jeremy Reiman

LSU Master's Theses

Rivers serve as an important medium for the exchange of elements between land, ocean, and atmosphere. This thesis consists of three interconnected studies with the overarching goal of analyzing the environmental factors influencing dissolved carbon dynamics and river geochemistry in large rivers. These studies utilized river water samples and in-stream measurements collected from the Mississippi and Atchafalaya Rivers at hourly to monthly intervals between 2013 to 2018, along with ambient river and meteorological data downloaded from public-access databases. Results indicate substantially higher dissolved organic carbon concentrations (DOC, 611 ±181 µmol L^-1) but lower concentrations of dissolved inorganic carbon …

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 …

Modeling The Effects Of Climate Variability On Hydrology And Stream Temperatures In The North Fork Of The Stillaguamish River, Kyra Freeman

WWU Graduate School Collection

The Stillaguamish River in northwest Washington State, USA, provides water resources to local agriculture, industry and First Nations Tribes, and provides crucial habitat for several endangered species of salmonids. The watershed experiences a mild maritime climate and high relief, with rain and snowmelt dominating the streamflow. In anticipation of shifts in snowpack, streamflow, and stream temperature, I use projected global climate scenarios and numerical models to examine future climatic variability on streamflow and stream temperatures in the snow-melt dominated North Fork of the Stillaguamish River. I calibrated the physically based Distributed Hydrology Soil Vegetation Model (DHSVM) and River Basin Model …

Ice Flow Impacts The Firn Structure Of Greenland's Percolation Zone, Rosemary C. Leone

Graduate Student Theses, Dissertations, & Professional Papers

One dimensional simulations of firn evolution neglect horizontal transport as the firn column moves down slope during burial. This approach is justifiable near Greenland's ice divide, where ice flow is near vertical, but fidelity is lost in the percolation zone where horizontal ice flow advects the firn column through climate gradients. We simulate firn evolution processes under advection conditions using a transient, thermo-mechanically coupled model for firn densification and heat transfer with various schemes for meltwater penetration and refreezing. The simulations isolate processes in synthetic runs and investigate an ice core site and four transects of Greenland’s percolation zone. The …

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 …

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 …

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 …

Biogeochemical Response To Vegetation And Hydrologic Change In An Alaskan Boreal Fen Ecosystem, Danielle L. Rupp

Dissertations, Master's Theses and Master's Reports

Boreal peatlands store approximately one third of the earth’s terrestrial carbon, locked away in currently waterlogged and frozen conditions. Peatlands of boreal and arctic ecosystems are affected increasingly by shifting hydrology caused by climate change. The consequences of these relatively rapid ecosystem changes on carbon cycling between the landscape and the atmosphere could provide an amplifying feedback to climate warming. Alternatively, the advancement of terrestrial vegetation into once waterlogged soils could uptake carbon as a sink. Previous work suggests that fens will become an increasingly dominant landscape feature in the boreal. However, studies investigating fens, their response to hydrologic and …