Index Catalog // ScholarsArchive@OSU

Nitrate and pesticide transport under pear production in clay and sandy soil

Creator:: Cao, Weidong
Abstract:: Groundwater contamination on irrigated land is of concern in this nation and around the world. In order to reduce the potential of groundwater contamination by agricultural practices such as irrigation, fertilizer and pesticide application, vadose-zone monitoring and sampling are needed. The main objective of this study was to evaluate impacts...
Resource Type:: Masters Thesis
Full Text:: clay and sandy soil AN ABSTRACT OF THE THESIS OF Weidonq Cao for the degree of Master of Science in

Feasibility of Thermal Restoration by Groundwater Additions in the Middle Fork John Day

Creator:: Hale, Abigail E.
Abstract:: Survival of ecological systems pivot on critical moments. In the arid John Day Basin of Eastern Oregon, extensive restoration of the stream and floodplain focused on supporting salmon has been ongoing for the past 20 years, but recurring short periods of extreme temperature increase and low flows result in mortality...
Resource Type:: Masters Thesis

Spillway Staging and Selective Sediment Deposition in Sand Storage Dams

Creator:: Viducich, Jonathan M. G.
Abstract:: Rainfall scarcity and variability present serious challenges to water security for many rural communities throughout the world's drylands. Sand dams--weirs built across ephemeral or seasonal rivers--provide an appropriate water harvesting and storage option for many regions. The structures quickly fill with sediment during rainy season flow events and store water...
Resource Type:: Masters Thesis
Full Text:: . Gijsbertsen found that mean catchment slopes greater than 2 degrees provide the strongest predictor of sandy

Investigating One-way Stream-aquifer Connectivity on Streamflow Predictions during Hydrologic Extremes in the National Water Model

Creator:: Jachens, Elizabeth R.
Abstract:: Surface water and groundwater are intimately connected by a two-way flux between the stream and the underlying aquifers; a complicated yet crucial relationship to represent in models. However, the National Water Model currently only considers a one-way flux, where groundwater can enter a stream but cannot return to the aquifer....
Resource Type:: Masters Thesis
Full Text:: Quaternary valley fill deposits with soil classes of sandy clay loam and aquifer saturated thickness

Characterization of hydrologic parameters and processes in shrink-swell clay soils

Creator:: Stewart, Ryan D.
Abstract:: Vertisols and other vertic-intergrade soils are found all over the globe, including many agricultural and urban areas. These soils are characterized by their cyclical shrinking and swelling behaviors, where bulk density and porosity distribution both vary as functions of time and/or soil moisture. In turn, alterations in physical soil parameters...
Resource Type:: Dissertation
Full Text:: possible impact. I also offer my sincere gratitude and appreciation to Drs. Majdi Abou Najm and David E

Hyperspectral Disease Detection - Strategies Addressing Time, Space, Machine Learning, and Plant Susceptibility

Creator:: Haagsma, Marja
Abstract:: Finding trees and crops that are resistant to pathogens is key in preparing for current and future disease threats. In this dissertation, we analyzed the potential of using hyperspectral imaging (HSI) to find infection while identifying issues and strategies addressing differences over time, in spatial resolution, the application of machine...
Resource Type:: Dissertation
Full Text:: like to thank everyone who has made Corvallis feel like my home: Kevin, Liz, Anna, Nicole, Sandy

A predictive model for time domain reflectometry soil water content and salinity measurements

Creator:: Flugstad, Benjamin A.
Abstract:: Soil water content and water potential are two important parameters in determining the status of water in the soil. Improvement in the ability to measure these parameters by way of increased speed, accuracy, resolution, imaging volume, ease of automation, as well as reduced calibration requirements and reduced soil disturbance would...
Resource Type:: Masters Thesis
Full Text:: in a sandy soil with the results showing good agreement between predictions and actual results but

Determining contact angle of solutions with varying surface tension on dry and pre-wetted silica sands

Creator:: McGinnis, Thomas L.
Abstract:: Infiltration of highly concentrated solutions into unsaturated sand is suspected to be affected by the liquid-gas interfacial tension between the resident water and that of the infiltrating solution. The wetting of non-porous solid surfaces by liquids is commonly quantified by contact angle measurements. However, it is well known that wettability...
Resource Type:: Masters Thesis
Full Text:: effective method to measure contact angle in coarse porous media such as sandy soils. In this study, we

Field evaluation of passive capillary samplers in monitoring the leaching of agrochemicals

Creator:: Brandi-Dohrn, Florian M.
Abstract:: Soil solution samplers have certain inadequacies that limit their range of possible applications. Passive Capillary Samplers (PCAPS), which apply suction to the soil pore-water via a fiber glass wick, have shown promising results in preliminary experiments in regard to collection efficiency of water and of bromide tracers. The objectives of...
Resource Type:: Masters Thesis
Full Text:: variance, and E the allowable absolute error in the mean. Following Holder et al. (1991), the sample

Evaluation of techniques for on-farm monitoring of percolation and irrigation system performance

Creator:: Louie, Michael J.
Abstract:: Efficient use of water in agricultural production involves accurate assessment and control of the quantity and spatial uniformity of excess percolation. Passive Capillary Samplers (PCAPS), which sample water from the vadose zone have shown potential to provide superior estimates of soil water flux compared to alternative methods. In a four-year...
Resource Type:: Masters Thesis
Full Text:: Crop #6 Soil Series Cloquato silt loam Newberg fine sandy loam Coburg silty clay loam Newberg fine

ScholarsArchive@OSU

Nitrate and pesticide transport under pear production in clay and sandy soil

Feasibility of Thermal Restoration by Groundwater Additions in the Middle Fork John Day

Spillway Staging and Selective Sediment Deposition in Sand Storage Dams

Investigating One-way Stream-aquifer Connectivity on Streamflow Predictions during Hydrologic Extremes in the National Water Model

Characterization of hydrologic parameters and processes in shrink-swell clay soils

Hyperspectral Disease Detection - Strategies Addressing Time, Space, Machine Learning, and Plant Susceptibility

A predictive model for time domain reflectometry soil water content and salinity measurements

Determining contact angle of solutions with varying surface tension on dry and pre-wetted silica sands

Field evaluation of passive capillary samplers in monitoring the leaching of agrochemicals

Evaluation of techniques for on-farm monitoring of percolation and irrigation system performance

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