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Articles 1 - 21 of 21
Full-Text Articles in Physical Sciences and Mathematics
High-Performance Domain-Specific Library For Hydrologic Data Processing, Kalyan Bhetwal
High-Performance Domain-Specific Library For Hydrologic Data Processing, Kalyan Bhetwal
Boise State University Theses and Dissertations
Hydrologists must process many gigabytes of data for hydrologic simulations, which takes time and resources degrading performance. The performance issues are caused mainly by domain scientists’ preference for using Python, which trades performance for productivity. In my thesis, I demonstrate that using the static compilation technique to compile Python to generate C code along with several optimizations reduces time and resources for hydrologic data processing. I developed a Domain Specific Library (DSL) which is a subset of Python and compiles to Sparse Polyhedral Framework - Intermediate Representation (SPF-IR), which allows opportunities for optimizations like read reduction fusion which are not …
A Classification Framework To Assess Ecological, Biogeochemical, And Hydrologic Synchrony And Asynchrony, Kendra E. Kaiser
A Classification Framework To Assess Ecological, Biogeochemical, And Hydrologic Synchrony And Asynchrony, Kendra E. Kaiser
Geosciences Faculty Publications and Presentations
Ecosystems in the Anthropocene face pressures from multiple, interacting forms of environmental change. These pressures, resulting from land use change, altered hydrologic regimes, and climate change, will likely change the synchrony of ecosystem processes as distinct components of ecosystems are impacted in different ways. However, discipline-specific definitions and ad hoc methods for identifying synchrony and asynchrony have limited broader synthesis of this concept among studies and across disciplines. Drawing on concepts from ecology, hydrology, geomorphology, and biogeochemistry, we offer a unifying definition of synchrony for ecosystem science and propose a classification framework for synchrony and asynchrony of ecosystem processes. This …
Water Quality Responses To A Semi-Arid Beaver Meadow In Boise, Idaho, Luise Bayer Winslow
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
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 …
Using Remote Sensing Data Fusion Modeling To Track Seasonal Snow Cover In A Mountain Watershed, Allison N. Vincent
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 …
Pooling Data Improves Multimodel Idf Estimates Over Median-Based Idf Estimates: Analysis Over The Susquehanna And Florida, Abhishekh Kumar Srivastava, Richard Grotjahn, Paul Aaron Ullrich, Mojtaba Sadegh
Pooling Data Improves Multimodel Idf Estimates Over Median-Based Idf Estimates: Analysis Over The Susquehanna And Florida, Abhishekh Kumar Srivastava, Richard Grotjahn, Paul Aaron Ullrich, Mojtaba Sadegh
Civil Engineering Faculty Publications and Presentations
Traditional multimodel methods for estimating future changes in precipitation intensity, duration, and frequency (IDF) curves rely on mean or median of models’ IDF estimates. Such multimodel estimates are impaired by large estimation uncertainty, shadowing their efficacy in planning efforts. Here, assuming that each climate model is one representation of the underlying data generating process, i.e., the Earth system, we propose a novel extension of current methods through pooling model data: (i) evaluate performance of climate models in simulating the spatial and temporal variability of the observed annual maximum precipitation (AMP), (ii) bias-correct and pool historical and future AMP data of …
Snow Depth Variability In The Northern Hemisphere Mountains Observed From Space, Hans-Peter Marshall
Snow Depth Variability In The Northern Hemisphere Mountains Observed From Space, Hans-Peter Marshall
Geosciences Faculty Publications and Presentations
Accurate snow depth observations are critical to assess water resources. More than a billion people rely on water from snow, most of which originates in the Northern Hemisphere mountain ranges. Yet, remote sensing observations of mountain snow depth are still lacking at the large scale. Here, we show the ability of Sentinel-1 to map snow depth in the Northern Hemisphere mountains at 1 km² resolution using an empirical change detection approach. An evaluation with measurements from ~4000 sites and reanalysis data demonstrates that the Sentinel-1 retrievals capture the spatial variability between and within mountain ranges, as well as their inter-annual …
Assessment Of Snow Atmosphere Forcing During Central Idaho Atmospheric Rivers, William Rudisill
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 …
Geochemical Dynamics And Nitrous Oxide Release From The Hyporheic Zone Of Streams, Annika Marie Quick
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 …
Application Of Hydrogeophysical Imaging In The Reynolds Creek Critical Zone Observatory, Travis Nielson
Application Of Hydrogeophysical Imaging In The Reynolds Creek Critical Zone Observatory, Travis Nielson
Boise State University Theses and Dissertations
The critical zone is defined as the upper most portion of the crust extending from the top of unweathered bedrock to the top of the vegetation canopy. It is the zone in which inorganic rock is transformed into biologically useful soils and saprolites in a process termed weathering. Because the critical zone is the connection between the subsurface and surface it plays a role in a wide variety of biological, hydrologic, and climatic processes. Understanding the critical zone though is inherently difficult because its scale and heterogeneity often means direct sampling methods, e.g. soil pits and cores, under represent the …
Feedbacks Among Climate, Soils, Vegetation, And Erosion Drive Valley Asymmetry Development In The Mountains Of Central Idaho, Michael John Poulos
Feedbacks Among Climate, Soils, Vegetation, And Erosion Drive Valley Asymmetry Development In The Mountains Of Central Idaho, Michael John Poulos
Boise State University Theses and Dissertations
Aspect has long been recognized as a significant source of landscape variability, which is induced by the orientation of land surfaces relative to solar incidence. Insolation differences on opposing aspects (e.g., north and south-facing slopes) act as localized climatic perturbations, altering surface energy balances and temperatures. Over shorter timescales, aspect-induced changes to the energy balance alter snow pack dynamics, soil water input rates and seasonality, and plant available water and water stress. Over longer timescales, aspect-induced insolation variability affects bedrock weathering rates and depths, soil and regolith development, vegetation type and density, erosion rates and processes, and ultimately hillslope and …
Stable Isotopes Reveal A Disconnect Between Biotic And Abiotic Hydrological Processes In A Seasonally-Dry, Semi-Arid Watershed, Ryan James Mccutcheon
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 …
Dynamical Precipitation Downscaling For Hydrologic Applications Using Wrf 4d-Var Data Assimilation: Implications For Gpm Era, Liao-Fan Lin, Ardeshir M. Ebtehaj, Rafael L. Bras, Alejandro N. Flores, Jingfeng Wang
Dynamical Precipitation Downscaling For Hydrologic Applications Using Wrf 4d-Var Data Assimilation: Implications For Gpm Era, Liao-Fan Lin, Ardeshir M. Ebtehaj, Rafael L. Bras, Alejandro N. Flores, Jingfeng Wang
Geosciences Faculty Publications and Presentations
The objective of this study is to develop a framework for dynamically downscaling spaceborne precipitation products using the Weather Research and Forecasting (WRF) Model with four-dimensional variational data assimilation (4D-Var). Numerical experiments have been conducted to 1) understand the sensitivity of precipitation downscaling through point-scale precipitation data assimilation and 2) investigate the impact of seasonality and associated changes in precipitation-generating mechanisms on the quality of spatiotemporal downscaling of precipitation. The point-scale experiment suggests that assimilating precipitation can significantly affect the precipitation analysis, forecast, and downscaling. Because of occasional overestimation or underestimation of small-scale summertime precipitation extremes, the numerical experiments presented …
Transfer Of Snow Information Across The Macro-To-Hillslope-Scale Gap Using A Physiographic Downscaling Approach: Implications For Hydrologic Modeling In Semiarid, Seasonally Snow-Dominated Watersheds, Reggie D. Walters
Boise State University Theses and Dissertations
Snow and ice are substantial components of the global energy balance and hydrologic cycle. Seasonal snow covers an area of 47 million km2 at its average maximum extent, 98% of which occurs across the Northern Hemisphere. The earth’s radiation budget is largely controlled by the fraction of absorbed solar energy, a parameter that is dependent upon snow surface albedo. Mountain snowpacks act as natural reservoirs, storing large quantities of water throughout the winter until eventual release during the melting phase. Accurate characterization of snow-covered area (SCA) and snow water equivalent (SWE) in such terrain could substantially improve the estimation …
Discontinuous Parameter Estimates With Least Squares Estimators, J. L. Mead
Discontinuous Parameter Estimates With Least Squares Estimators, J. L. Mead
Mathematics Faculty Publications and Presentations
We discuss weighted least squares estimates of ill-conditioned linear inverse problems where weights are chosen to be inverse error covariance matrices. Least squares estimators are the maximum likelihood estimate for normally distributed data and parameters, but here we do not assume particular probability distributions. Weights for the estimator are found by ensuring its minimum follows a χ2 distribution. Previous work with this approach has shown that it is competitive with regularization methods such as the L-curve and Generalized Cross Validation (GCV) [20]. In this work we extend the method to find diagonal weighting matrices, rather than a scalar regularization …
The Hydrologic Significance Of Lateral Water Flow Through Snow, David Parker Eiriksson
The Hydrologic Significance Of Lateral Water Flow Through Snow, David Parker Eiriksson
Boise State University Theses and Dissertations
Understanding the mechanisms by which catchments route vertical water inputs laterally to stream channels is central to the development of accurate predictive models of watershed processes. It is commonly assumed that lateral redistribution occurs as overland or subsurface flow. Lateral flow can also occur within the snowpack during rain-on-snow (ROS) events or spring melt, sometimes resulting in surface expressions commonly called "runnels." This thesis examines lateral flow through snow and the role of the snowpack as a rapid down-slope water delivery mechanism, with the goal of determining if lateral flow through snow is an important control on streamflow generation and …
Spatial Distribution And Evolution Of A Seasonal Snowpack In Complex Terrain: An Evaluation Of The Snodas Modeling Product, Brian Trail Anderson
Spatial Distribution And Evolution Of A Seasonal Snowpack In Complex Terrain: An Evaluation Of The Snodas Modeling Product, Brian Trail Anderson
Boise State University Theses and Dissertations
Hydrologists and water managers have been attempting to accurately estimate watershed scale snow water equivalent (SWE) for over a century. Extensive monitoring networks, remote sensing technology, and sophisticated modeling approaches have greatly improved these estimates; however, water inputs from snow in mountainous areas are still subject to considerable uncertainty due to SWE spatial variability. In an attempt to improve the understanding of physical processes and controls influencing SWE spatial variability, a field campaign to measure the spatial and temporal distribution of SWE within the Dry Creek Experimental Watershed (DCEW) was conducted during 2009 and 2010. These measurements are compared to …
Arctic Landscapes In Transition: Responses To Thawing Permafrost, James P. Mcnamara
Arctic Landscapes In Transition: Responses To Thawing Permafrost, James P. Mcnamara
Geosciences Faculty Publications and Presentations
Observations indicate that over the past several decades, geomorphic processes in the Arctic have been changing or intensifying. Coastal erosion, which currently supplies most of the sediment and carbon to the Arctic Ocean [Rachold et al., 2000], may have doubled since 1955 [Mars and Houseknecht, 2007]. Further inland, expansion of channel networks [Toniolo et al., 2009] and increased river bank erosion [Costard et al., 2007] have been attributed to warming. Lakes, ponds, and wetlands appear to be more dynamic, growing in some areas, shrinking in others, and changing distribution across lowland regions …
Modeling Soil Depth From Topographic And Land Cover Attributes, Teklu K. Tesfa, David G. Tarboton, David G. Chandler, James P. Mcnamara
Modeling Soil Depth From Topographic And Land Cover Attributes, Teklu K. Tesfa, David G. Tarboton, David G. Chandler, James P. Mcnamara
Geosciences Faculty Publications and Presentations
Soil depth is an important input parameter in hydrological and ecological modeling. Presently, the soil depth data available in national soil databases (STATSGO and SSURGO) from the Natural Resources Conservation Service are provided as averages within generalized land units (map units). Spatial uncertainty within these units limits their applicability for distributed modeling in complex terrain. This work reports statistical models for prediction of soil depth in a semiarid mountainous watershed that are based upon the relationship between soil depth and topographic and land cover attributes. Soil depth was surveyed by driving a rod into the ground until refusal at locations …
Application Of Time-Lapse Ert Imaging To Watershed Characterization, Carlyle R. Miller, Partha S. Routh, Troy R. Brosten, James P. Mcnamara
Application Of Time-Lapse Ert Imaging To Watershed Characterization, Carlyle R. Miller, Partha S. Routh, Troy R. Brosten, James P. Mcnamara
Geosciences Faculty Publications and Presentations
Time-lapse electrical resistivity tomography (ERT) has many practical applications to the study of subsurface properties and processes. When inverting time-lapse ERT data, it is useful to proceed beyond straightforward inversion of data differences and take advantage of the time-lapse nature of the data. We assess various approaches for inverting and interpreting time-lapse ERT data and determine that two approaches work well. The first approach is model subtraction after separate inversion of the data from two time periods, and the second approach is to use the inverted model from a base data set as the reference model or prior information for …
Depth Characterization Of Shallow Aquifers With Seismic Reflection, Part Ii—Prestack Depth Migration And Field Examples, John H. Bradford, D. S. Sawyer
Depth Characterization Of Shallow Aquifers With Seismic Reflection, Part Ii—Prestack Depth Migration And Field Examples, John H. Bradford, D. S. Sawyer
CGISS Publications and Presentations
It is common in shallow seismic studies for the compressional-wave velocity in unconsolidated sediments to increase by a factor of four or more at the transition from dry or partial water saturation to full saturation. Under these conditions, conventional NMO velocity analysis fails and leads to large depth and layer thickness estimates if the Dix equation is assumed valid. Prestack depth migration (PSDM) is a means of improving image accuracy. A comparison of PSDM with conventional NMO processing for three field examples from differing hydrogeologic environments illustrates that PSDM can significantly improve image quality and accuracy.