Physical Sciences and Mathematics Commons^™

Application Of A High-Resolution Climate Model Dataset To Assess Habitat Suitability For Spotted Wing Drosophila In Southwest Idaho, Elizabeth Padian

Boise State University Theses and Dissertations

As global climate change continues to produce large deviations from the normals of the 19th and 20th centuries, the agricultural sector will need to adapt to these changes in order to maintain yields and feed the global population. Crop selections, yield amounts, and pest management techniques may need to be adjusted to adapt. The Spotted Wing Drosophila (SWD) is a small fruit fly-like bug that can infest berries and stone fruit crops by burrowing into the fruit (at most points in the fruit’s lifecycle) and laying its eggs. These eggs will hatch and the larvae will burrow back out of …

Hydrologic Implications Of Snow-Vegetation Interactions In A Semiarid Mountain Climate, Maggi Kraft

Boise State University Theses and Dissertations

Knowledge of the complex interaction between snow, vegetation, and streamflow in semiarid mountain climates is necessary for predicting water resources. The effects of warming temperatures on snow distribution will cascade into vegetation water use and streamflow. Due to our reliance on snow water resources, it is necessary to understand how vegetation affects snow distribution, how vegetation uses snow water inputs and the subsequent effects on streamflow in the current and warming climate. The overall objective of this research is to improve our understanding of snow-vegetation interactions in a semiarid climate. In this dissertation, I use field data to evaluate how …

Exploring Hydrologic Responses To Different Wildfire Spatial Patterns Through The Lens Of Computational Modeling, Luke M. Telfer

Boise State University Theses and Dissertations

Severe wildfire disturbances are becoming increasingly common in high-elevation forests of the western United States. These fires alter watershed hydrologic processes, threatening critical downstream water resources and aquatic ecosystems. However, watershed-scale postfire hydrologic responses and water balance changes are highly uncertain. While postfire effects on individual processes such as runoff, infiltration, evapotranspiration, and snow dynamics are relatively well known, the role of wildfire spatial patterns in governing hydrologic connectivity and interactions between water balance components is poorly understood due to challenges associated with measuring and comparing fires at large scales. This thesis aims to examine pattern-related postfire interactions between various …

Water Quality Responses To A Semi-Arid Beaver Meadow In Boise, Idaho, Luise Bayer Winslow

Boise State University Theses and Dissertations

Beavers have been instrumental in shaping the North American riverine landscape. However, land use change and beaver trapping have caused large decreases in beaver populations, resulting in fundamental changes to river morphology, hydrology, and biogeochemical function. Effective river restoration and remediation of arid western rivers relies on a comprehensive interpretation of how beaver activity influences water quantity and quality. In this study, I compared two stream reaches with and without beaver dams in a semi-arid watershed, to quantify the effects of beaver activity on hydrology and biogeochemistry. Within each reach, I combined dilution gauging and stream tracer experiments to determine …

Laboratory Measurement Of Electrical And Hydraulic Properties Of Regolith Over Granitic Bedrock, Taylor James Bienvenue

Boise State University Theses and Dissertations

Characterizing water flux within the critical zone (CZ) is essential for a multitude of studies and applications related to irrigation, drainage, water management, and contaminant transport. Trying to measure water flux in the critical zone, specifically in the subsurface, is difficult due to the associated structural heterogeneity and complex interactions taking place between biological, chemical, and physical processes. Current methods (i.e., inferred from soil suction and soil moisture measurements) to characterize water flux within the critical zone can be time consuming and are not directly related to water flux. Recent literature has provided evidence that self-potential (SP) is a promising …

Assessment Of Icesat-2 Level 3a Products For Snow Depth Estimation In Remote, Mountainous Watersheds, Colten Michael Elkin

Boise State University Theses and Dissertations

Seasonal snowpack accounts for ~70% of the water supply in the western United States, and measuring snow accumulation and ablation remotely has long been a stated goal of NASA. The 2018 launch of ICESat-2, a spaceborne Lidar system, has offered unparalleled spatial and temporal coverage of mountainous terrain with the potential for unprecedented vertical accuracy. Data from ICESat-2 are used to measure seasonal snow depths using the level-3A ATL08 (land and canopy elevation) product for the Reynolds Creek Experimental Watershed in southwest Idaho and the ATL06 (land ice elevation) product for Wolverine Creek in the Kenai Mountains of Alaska. The …

Using Remote Sensing Data Fusion Modeling To Track Seasonal Snow Cover In A Mountain Watershed, Allison N. Vincent

Boise State University Theses and Dissertations

Seasonal snowfall is the largest component of the water budget in many mountain headwater regions around the world. In addition to sustaining biological water needs in drier, lower elevation areas throughout the year, mountain snowpack also provides essential water inputs to the Critical Zone (CZ) - the outer layer of the Earth’s surface, which hosts a variety of biogeochemical processes responsible for transforming inorganic matter into forms usable for life. Water is a known driver of CZ activity, but uncertainty exists in its spatial and temporal interactions with CZ processes, particularly in the complex terrain of heterogeneous mountain areas. Increasing …

The Signal Of Modern To Holocene Drivers Of Complex Channel Response Of A Small Alluvial Stream, Scott D. Ducar

Boise State University Theses and Dissertations

Small alluvial streams (~100km² drainage area) are important for water resources and aquatic habitat. Small streams throughout the Western United States are impacted by anthropogenic land-use including urban development, mining, logging, beaver trapping, grazing, and farming. Land-use change can trigger a complex series of channel response (such as stream channel incision or channel migration) that vary spatially and temporally in the watershed. However, streams also respond to other external forcings, such as tectonically or climatically-driven changes in discharge or base-level, which make disentangling the drivers of channel response complicated. Therefore, it is important to place modern channel changes into …

A 30-Year Agroclimatic Analysis Of The Snake River Valley American Viticultural Area - Descriptive And Predictive Methods, Charles L. Becker

Boise State University Theses and Dissertations

Climate change poses serious threats to global agriculture, however some localities and crops may benefit from increasing temperatures. Grape production in southern Idaho may be a beneficial example as vineyard acreage has increased over 300% since the designation of the Snake River American Viticultural Area (SRVAVA) in 2007. We perform a statistical characterization of agroclimate within the SRVAVA that centers around four primary objectives: utilization of a novel, 30-year high resolution climate dataset to provide insight and agrometrics unavailable at coarser resolutions, climatic implications of the unique topography within the SRVAVA, identification of statistical trends, and correlation of SRVAVA climate …

Applications Of Continuous Snowpack Temperature Monitoring, Peter J. Youngblood

Boise State University Theses and Dissertations

Predicting metamorphism within seasonal snowpacks is critical for avalanche forecasting and runoff timing as it relates to water supply management. Snowpack temperature gradients play a key role in snow metamorphism, and their magnitude controls how snow strength changes; therefore, they are of interest to avalanche forecasters. Before major melt, the snowpack must warm to isothermal conditions at 0°C. Measuring this transition from warming to the ripening phase could help improve our current models for runoff timing. Measuring snowpack temperature gradients is currently a non-automated process that requires disturbance of the snow profile, and only gives a snapshot in time of …

The Spatial Distribution Of Elevated Uranium In The Treasure Valley Aquifer System, Southwest Idaho, Lloyd A. Womeldorph

Boise State University Theses and Dissertations

The Treasure Valley Aquifer System (TVAS) in southwestern Idaho contains well-documented uranium concentrations over the U.S. Environmental Protection Agency maximum contaminant level of 30 µg/L. With a population in the Treasure Valley projected to reach 1.6 million by 2065, in-depth horizontal and vertical spatial knowledge of the contaminant is needed. This study evaluates the horizontal and vertical spatial nature of uranium in the TVAS and interprets those observations to provide both a conceptual model of uranium behavior, and recommendations for water resource management. A large water quality dataset was compiled, and supplemented by data collected during a field sampling campaign, …

Does The Urbanization Of Agricultural Land Lead To More Or Less Evapotranspiration?, Curtis Ryan Crandall

Boise State University Theses and Dissertations

Agricultural areas within the western U.S. are undergoing rapid urbanization due to population growth. Urban expansion often forces the conversion of adjacent agricultural areas altering the landscape vegetation and associated water consumption through evapotranspiration (ET). The associated difference in ET may alter the landscape water demand complicating water resource management. To investigate these differences, we calculated the agricultural and urban seasonal ET rates in a semiarid watershed currently undergoing large population growth and rapid urbanization. We used high resolution satellite imagery with a GIS computer model to generate basin-wide ET estimates over a 204-day irrigation season. Six land type samples …

Cross-Scale Interactions Between Atmospheric And Hydrologic Processes In A Topographically Complex, Snow-Dominated Watershed As Revealed Through An Integrated Hydrologic Model, Miguel A. Aguayo Arias

Boise State University Theses and Dissertations

In much of the world, water for agricultural, domestic, and hydroelectric power generation uses are derived from snow-dominated mountain basins. In these regions, water management requires accurate and timely knowledge of runoff generation by snowmelt. This information is used to plan reservoir releases for downstream users and is generated by models of biophysical processes associated with varying degrees of fidelity to physical processes and/or spatial heterogeneities. The large variability in the characteristic spatial and temporal scales of atmospheric forcings, land-surface water and energy balance, and groundwater flow contribute to significant uncertainties in resolved hydrologic states and fluxes. Underlying sources of …

Investigating The Annual Water Balance Of A High-Altitude Watershed Using Near-Real Time Lidar Data Integration Into A Physically Based Snowmelt Model, Andrew R. Hedrick

Boise State University Theses and Dissertations

Knowledge of the amount of water stored in the mountain snowpack is crucial for flood prevention, drought mitigation, and energy production in the Western United States. In modeling terms, the most important component of the hydrologic water balance is the precipitation input to the system. Determining where and how much precipitation falls in mountain catchments, however, is the most difficult problem with regards to closing the water balance. The work presented in this dissertation details the modeling portion of the NASA Airborne Snow Observatory (ASO) using the iSnobal physically based snow model. This combination of remote sensing and modeling at …

Correlating The Spatial Distribution Of Snow Depth To Forest Canopy Parameters Derived From Terrestrial Laser Scans, Zachary Uhlmann

Boise State University Theses and Dissertations

In nonpolar, cold climate zones, snow accounts for 17% of the total terrestrial water storage. Estimating the amount of water stored in a snowpack, the snow water equivalent (SWE), and its spatial distribution is crucial to providing water managers with parameters to predict runoff timing, duration and amount. Reservoir management, hydropower and flood forecasting depend on SWE estimates. While landscape features such as aspect and slope are dominant controls on radiative energy in non-forested areas, forest cover can shift the energy balance composition from turbulent exchange in exposed, windy sites to primarily radiative inputs in the subcanopy. Additionally, forest cover …

From Snow To Flow: Exploring Relationships Between Snotel Ablation Curves And Peak Streamflow Timing, Kara Jane Ferguson

Boise State University Theses and Dissertations

Predictions of peak streamflow timing in snow-dominated river systems are essential for proper water management and recreational availability. This study evaluates historic snow and streamflow data from 14 river basins throughout Idaho to investigate the relationship between snowmelt timing at SNOw TELemetry (SNOTEL) sites and peak streamflow within each basin. The goal is to provide a simple operational tool that estimates the probability of peak streamflow occurring within a certain number of days as ablation progresses from 0 to 100% melted. For individual basins we evaluate meltout levels in increments of 10% from each SNOTEL site and use a probabilistic …

Exploring The Role Of Deforestation On Regional Hydroclimate In Southeast Africa: An Approach Fusing Models And Data, Megan Maksimowicz

Boise State University Theses and Dissertations

Land cover acts as the gatekeeper to incoming and outgoing energy and water fluxes at the land surface, partitioning energy and water in accordance with the vegetation type and in response to atmospheric forcings. As Land Surface Models become more complex and more capable of simulating the coupled dynamics of the land-atmosphere system in greater spatial detail, the need for accurate representation of spatial distribution of vegetation types and their dynamics through time grows.

As humans modify land cover, there are complex dynamics at play between the vegetation, the surface energy balance and the cycling of water. The resultant hydroclimatic …

Evaporation Depth Controls The Relationship Between Soil Water Mobility And Soil Water Isotopic Composition, John Byars Shuler

Boise State University Theses and Dissertations

Recent studies of plant water uptake assume that soil water isotopic composition can be used to infer soil water mobility. However, the strength of the relationship between mobility and isotopic composition remains poorly constrained. In addition, many ecohydrologic investigations are restricted by low sampling frequencies and insufficient soil moisture and matric potential data to support assumptions of soil water mobility. We sampled bulk soil water every 14 to 21 days in hillslope and riparian profiles during the 2016 and 2017 growing seasons in a semi-arid watershed outside Boise, ID. We collected twig samples of four tree and shrub species concurrently. …

Assessment Of Snow Atmosphere Forcing During Central Idaho Atmospheric Rivers, William Rudisill

Boise State University Theses and Dissertations

Atmospheric Rivers (AR) are globally occuring weather features and the primary mechanism through which water vapor moves from the tropics and subtropics towards the mid-latitudes, doing so at rates comparable to the world’s largest terrestrial rivers. AR that encounter mountains often cause extreme precipitation in the form of rain and snow, high winds, and flooding in many watersheds. They account for as much as 20-30% of cool season precipitation in the central Idaho Mountains. In the Northern Hemisphere, seasonal snow cover during Winter and Spring months is the most variable land surface component in space and time, and acts on …

Using Landlab, A Fine Scale Biogeography Model, To Measure The Sustainability Of Semi-Arid Vegetation In A Changing Climate, Lucy Gelb

Boise State University Theses and Dissertations

The distribution of vegetation in water-limited ecosystems is a product of complex and nonlinear interactions between climatic forcings (e.g., precipitation, temperature, solar radiation) and the underlying geomorphic template, which includes topography, geology, and soils. Changes in climate, particularly in precipitation and temperature, can dramatically alter the organization of vegetation. This is especially true in ecotones such as our area of study: the semi-arid transition between Great Basin shrub-steppe ecosystems and the coniferous forests of the Northern Rockies. Understanding and predicting how the spatial composition of terrestrial vegetation communities will change in these ecosystems is critical to predicting important future landscape …

Geochemical Dynamics And Nitrous Oxide Release From The Hyporheic Zone Of Streams, Annika Marie Quick

Boise State University Theses and Dissertations

The hyporheic zones of streams and rivers, consisting of the sediments beneath and immediately adjacent to the stream channel, are an important site of geochemical processing. Due to the difficulty of measuring these geochemical processes in the hyporheic zone in situ with meaningful spatial and temporal resolution, we conducted multiple column and large-scale flume experiments to model 1D and 2D hyporheic flow paths and observed important geochemical reactions, including the production and consumption of nitrous oxide (N₂O). N₂O is a significant greenhouse gas, but the controls on its emissions from streams are poorly constrained. We describe …

Mapping Soil Organic Carbon (Soc) In A Semi-Arid Mountainous Watershed Using Variables From Hyperspectral, Lidar And Traditional Datasets, Ryan Matthew Will

Boise State University Theses and Dissertations

Quantifying soil organic carbon (SOC) in complex terrain is challenging due to its high spatial variability. Generally, limited discrete observations of SOC data are used to develop spatially distributed maps of SOC by developing quantitative relationships between SOC and available spatially distributed variables. In many ecosystems, remotely sensed information on aboveground vegetation can be used to predict belowground carbon stocks. In this research, we developed maps of SOC across a semi-arid watershed based on discrete field observations and modeling using a suite of variables inclusive of hyperspectral and lidar datasets; these observations provide insights into the controls on soil carbon …

Trace Chemical Evaluation Of Cloud Seeding In The Payette Basin, James Mitchell Fisher

Boise State University Theses and Dissertations

Glaciogenic cloud seeding increases the fraction of super cooled liquid water precipitating from a given storm. Orographic clouds tend to be inefficient at higher cloud temperatures due to the lack of active natural ice nuclei. Adding artificial ice nuclei active at temperatures greater than -12^oC (where most natural ice nuclei are inactive) may result in an increase in snow precipitation, especially in orographic clouds. Silver iodide (AgI) is typically the artificial nucleating agent for winter orographic cloud seeding. Recent estimates suggest the addition of AgI to orographic storm clouds enhance precipitation by 3 - 15%. However, the National …

Exploring The Impact Of Climate And Land Cover Change On Regional Hydrology In A Snowmelt-Dominated Watershed: The Upper Boise River Basin, Idaho, Amy Steimke

Boise State University Theses and Dissertations

Seasonally snow-dominated, mountainous watersheds supply water to many human populations globally. However, the timing and magnitude of water delivery from these watersheds has already and will continue to change as climate is altered. Associated changes in watershed vegetation cover further affect the runoff responses of watersheds, from altering evapotranspiration rates to changing surface energy fluxes, and there exists a need to incorporate land cover change in hydrologic modeling studies. However, few land cover projections exist at the scale needed for watershed studies, and current models may be unable to simulate key interactions that occur between land cover and hydrologic processes. …

Using Mountain Snowpack To Predict Summer Water Availability In Semiarid Mountain Watersheds, Rebecca Dawn Garst

Boise State University Theses and Dissertations

In the mountainous landscapes of the western United States, water resources are dominated by snowpack. As temperatures rise in spring and summer, the melting snow produces an increase in river flow levels. Reservoirs are used during this increase to retain surplus water, which is released to supplement growing season water supply once the peak flows decrease to below water demands. Once there is no longer surplus natural flow of water, the water accounting changes – referred to as the day of allocation (DOA), and water previously retained within the reservoir is used to supplement the lower flow levels. The amount …

Riparian Zone Evapotranspiration Using Streamflow Diel Signals, Ethan Thomas Geisler

Boise State University Theses and Dissertations

Riparian zones are crucial regions of semi-arid and arid watersheds. In the summer, riparian zones provide an important habitat for the watershed since they have sufficient water supply throughout the year. However, little is known about the impact of riparian zone evapotranspiration (ET) at a watershed scale. The use of streamflow diel signals can provide a more thorough understanding of riparian zone processes, particularly evapotranspiration. The streamflow diel signals were analyzed for Dry Creek Experimental Watershed (DCEW), for the summer of 2014, to determine riparian evapotranspiration. The riparian zone evapotranspiration was compared to a spatially distributed evapotranspiration model to determine …

Using Stable Isotope Hydrology To Partition Evapotranspiration In The Sagebrush Steppe, Kellie Jo Rey

Boise State University Theses and Dissertations

Evapotranspiration (ET) is a major part of ecosystem water loss. This thesis aims to develop methods that partition soil water loss into evaporation (E) and transpiration (T). Water balance methods may improve with relative contributions of evaporation (E) and transpiration (T). Isotopic fractionation distinguishes soil water loss due to evaporation from that of plant uptake. This provides a means to assess E and T in retrospect rather than only measuring ET fluxes. To measure the isotopic composition of soil water, we used a liquid-vapor equilibration method following Wassenaar (2008). Experimental trials of different soil amounts and equilibration times were performed …

Stable Isotopes Reveal A Disconnect Between Biotic And Abiotic Hydrological Processes In A Seasonally-Dry, Semi-Arid Watershed, Ryan James Mccutcheon

Boise State University Theses and Dissertations

Until recently, it had been thought that humid catchment woody plants transpired primarily mobile soil water that would otherwise flow to streams or recharge groundwater. However, several recent studies have suggested that trees in seasonally-dry humid catchments use primarily tightly-bound, immobile soil water that does not fully mix with new precipitation or participate in translatory flow. McDonnell (2014) called this existence of two, hydrologically-distinct, water pools “the two water worlds hypothesis.” This ecohydrological behavior has important implications for understanding a wide range of catchment processes, including the spatial and temporal variability of evapotranspiration and nutrient cycling, and our abilities to …

Impacts Of Changing Snowmelt Timing On Non-Irrigated Crop Yield, Erin Murray

Boise State University Theses and Dissertations

As climate changes, the final date of spring snowmelt is projected to occur earlier in the year within the western United States. This earlier snowmelt timing may impact crop yield in snow-dominated watersheds by changing the timing of water delivery to agricultural fields. There is considerable uncertainty about how agricultural impacts of snowmelt timing may vary by region, crop type, and practices like irrigation vs. dryland farming. We utilize parametric regression techniques to isolate the magnitude of impact snowmelt timing has had on historical crop yield independently of climate and physiographic variables that also impact yield. To do this, we …

Estimating Unsaturated Flow Properties In Coarse Conglomeratic Sediment, Michael James Thoma Jr.

Boise State University Theses and Dissertations

In this dissertation, I address the lack of knowledge of unsaturated flow in coarse, conglomeratic sediment by determining if functional θ-ψ-K relationships, specifically van Genuchten-Mualem (VGM) relationships, developed to predict unsaturated flow in relatively fine-grained sediment can be directly applied to coarse, conglomeratic sediment. In the summer of 2011, a field-scale infiltration test was conducted at the Boise Hydrogeophysical Research Site to determine if functional ψ-θ-K relationships could be applied to infiltration in coarse, conglomeratic sediment, and to estimate parameter values for the VGM relationships. Vertically and laterally distributed ψ(t) and θ( …