Temperature anomalies can identify locations of seeps of groundwater into surface waters.
However, the method’s sensitivity to details such as thermometer burial depth, sediment material, seep
velocity, and surface water current are largely unknown. We report on a series of laboratory flume experiments
in which controlled seeps under variable sediment...
Full Text:
Selker, F., and J. S. Selker (2014), Flume testing of underwater seep detection
using temperature
Temperature anomalies can identify locations of seeps of groundwater into surface waters.
However, the method’s sensitivity to details such as thermometer burial depth, sediment material, seep
velocity, and surface water current are largely unknown. We report on a series of laboratory flume experiments
in which controlled seeps under variable sediment...
Temperature anomalies can identify locations of seeps of groundwater into surface waters.
However, the method’s sensitivity to details such as thermometer burial depth, sediment material, seep
velocity, and surface water current are largely unknown. We report on a series of laboratory flume experiments
in which controlled seeps under variable sediment...
Temperature anomalies can identify locations of seeps of groundwater into surface waters.
However, the method’s sensitivity to details such as thermometer burial depth, sediment material, seep
velocity, and surface water current are largely unknown. We report on a series of laboratory flume experiments
in which controlled seeps under variable sediment...
Water temperature in rivers and streams is an important factor for aquatic ecosystem health. Measurement of stream temperature has traditionally been accomplished by point temperature measurements, continuous point temperature loggers, and more recently, airborne remote sensing techniques such as Forward-Looking Infrared Radar (FLIR) or Thermal Infrared Radiometry. While each of...
This document describes the design and deployment of a first generation water vapor density sensing unit, the HumiSense. This device is based on an open, air-filled capacitor which is part of a resonant circuit. The frequency of the resonant circuit mixed with a fixed frequency oscillator is the basis of...
We found unexpected complexities resulting from the miscible displacement of a non-Newtonian fluid for both convergent and divergent flow as observed by displacing a miscible shear-thinning fluid (xanthan gum) in a radial Hele-Shaw cell. Such complex patterns have not been described before for either Newtonian or non- Newtonian fluids. A...
Temperature is a key factor for salmonid health and is an important restoration metric on the Middle Fork of the John Day River in northeast Oregon. In the past century, dredge mining, deforestation, and overgrazing have degraded stream habitat and resulted in greater daytime stream temperatures in the region. Recent...
Swelling soils cause millions of dollars of damage to buildings every year in the Unites States alone. One essential piece to understanding these soils is to understand how water moves through them. Hydraulic conductivity is a measure of how easily water flows through a soil. Currently, the most common method...
Sand dams – low-head dams built in ephemeral streambeds that store water within saturated sediments – are a proven means to increase water supplies for rural communities in arid and semiarid regions. Water percolates into the reservoir-impounded sediments during wet season rains and can subsequently be extracted during the dry...
Urban development causes changes in the hydrology, increasing stormwater runoff volumes, which often leads to flooding and ecosystem degradation. This is a common phenomenon in most urban Africa, due to lack of stormwater drainage infrastructures. Green Infrastructure (GI) has been shown to be an effective approach to lessen the effects...
In the face of climate change droughts are predicted to become more persistent, further intensifying the need for accurately predicting the timing and magnitude of summer streamflow in rivers. In order to determine the sensitivity of a watershed to drought, there is a need to describe what these drought conditions...
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...
Surface water and groundwater interactions are a key component in the functioning of stream ecosystems. Exchange of water between the stream and the hyporheic zone creates habitat for aquatic organisms and serves as a control for stream biogeochemical, thermal, and flow processes. This study takes a multi-method field-based approach to...
The agricultural production of peppermint has been shown to contribute significant quantities of nitrate-nitrogen to groundwater recharge. In an effort to provide new tools for increasing nitrogen efficiency within peppermint production, three research questions were proposed: i) How should plant tissue samples be collected to achieve the greatest precision when...
Water conservation and water quality are rapidly increasing in importance in all areas of the world. The ability to accurately measure soil water content and salinity, over a wide variety of conditions, is key to meeting this need. A set of forward prediction models and waveform interpretation algorithms to extract...
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....
As ornamental container nurseries face diminishing water allocations, many are looking to automated irrigation solutions to increase their water application efficiency. This thesis presents the findings of a study conducted at a commercial container nursery to determine 1) whether a capacitance or load cell sensor was better suited for monitoring...
A novel technique was developed for studying gas phase flow in unsaturated porous media. Carbon dioxide was pumped through a back-lit chamber packed with translucent sand which was variably saturated with water containing the pH indicator dye methyl red. As the carbon dioxide dissolved in the pore water, lowering the...
Headwater streams are an integral part of the ecological health of the greater stream network as they provide valuable biological habitat, provide upwards to 95% of total in channel flow, while providing downstream reaches with important constituents such as sediment and woody debris. Small headwater streams are particularly susceptible to...
An experimental and numerical modeling investigation was conducted to study interactions between microbial dynamics and transport processes in variably saturated porous media. These interactions are important in a variety of applied problems such as water and wastewater treatment, bioremediation, and oil-field recovery operations. These processes and interactions also have great...
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...
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...
Non-dilute salt strength solutions occur in many near surface geologic environments. In order to better understand the occurrence and movement of the water and salt, mathematical models for this non-ideal fluid need to be developed. Initial boundary value problems may then be solved to predict behavior for comparison with observations....
Linkages between land use and its influence on the atmosphere have been a long-standing research area. For example, what is the impact of irrigated agriculture on downwind rainfall? Global-scale models show that moisture recycling is an important source of water for inland regions around the world, but they do not...
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...
The City of Woodburn, Oregon's Wastewater Treatment Plant (WWTP) has been investigating several natural alternatives for improving effluent quality. Based on its current National Pollution Discharge Elimination System (NPDES) permit, the WWTP will require additional reduction of temperature and ammonia levels in the summer, especially in the critical month of...
The Clean Water Act imposes Total Maximum Daily Load (TMDL) limits on pollutant concentrations within wastewater effluent; in Oregon, thermal discharge is one of the pollutants subject to regulation. The City of Woodburn, Oregon, funded a series of pilot scale studies to investigate the utility of natural systems to reduce...
Land application of industrial wastewater with high levels of nitrogen requires
adequate management practices to prevent groundwater pollution by nitrates. In this study
a predictive computerized model was developed for nitrate leachate concentrations
resulting from land application of wastewater onto crop systems including poplars. The
study included a literature review,...
Assessment of the environmental impacts of an agricultural production system
requires information on both soil water quality and solute flux. Passive Capillary Samplers
(PCAPS), which sample water from the vadose zone using fiber glass wicks, have shown
potential to provide both flux and solute concentration in unsaturated zone sampling but...
The contamination of ground water resources represents a serious
problem and a prominent threat to the health of our society. This study
focuses on the leaching of inorganic anions as a function of agricultural
practices under natural field conditions. In order to enhance the
understanding of such leaching processes, this...
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...
As the number of weather stations declines globally, ensuring that meteorological monitoring networks efficiently and effectively monitor weather variables becomes increasingly important. Multi-variable weather sensors are becoming more widely available and make monitoring weather phenomena more economical. However, when seeking an optimal spatial distribution of these stations, choosing an objective...
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...
Diking and channelizing in the Toppenish Creek basin, associated with irrigated agricultural development, has altered its natural ecosystem function and hydraulic processes. We seek to answer two research questions: if surface waters are diverted for aquifer recharge in the winter, will this water be available for ecosystem function in the...
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...
Solute transport models in karst groundwater must consider variable and complex flow regimes. Within fissures less than 2 mm in aperture, during unsaturated flow events, seeping flow may flow as films or under capillary tension as a capillary rivulet. This project focuses on exploring the mass transport characteristics of seeping...
In order to determine how contaminants from pharmaceutical, agriculture, and industry will move through groundwater systems, it is imperative to further our understanding of the relationship between physical, biological, and chemical properties of aquifers and transport and transformation of these products. Several studies have explored how heterogeneities in groundwater systems...
Understanding the processes involved in the transport of dissolved gas plumes in groundwater aquifers is essential for comprehending the effect that these transport processes can have on site characterization and remedial design applications. Previous laboratory and field studies have indicated that dissolved gas transport in groundwater can be greatly affected...
As climate change contributes to larger and more severe wildfires in California, areas of fire refugia – considered unburned and low-severity burn patches – are playing an increasingly important role in sustaining ecosystem resilience, maintaining biodiversity, and supporting post-disturbance recovery. At the same time, climate refugia – which are areas...
Hyperspectral images were taken from March till October, 2018, of southwestern white pine (Pinus strobiformis), SWWP, seedlings of ten different seed-source families. Half of the seedlings were inoculated with white pine blister rust (Cronartium ribicola). Visual assessments of vigor coincided with hyperspectral data acquisition.
The aim of the experiment was...
Salicylate-induced, lux gene dependent bioluminescence was measured using a cooled charge-coupled device (CCD) camera to evaluate its potential as a quantitative measurement of cell density of Pseudomonas fluorescens HK44 in porous media. The CCD camera was able to detect bioluminescence from cell densities between 1x10⁶ and 1x10⁸ cells/ml in both...
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...
Achieving and maintaining sustainability in irrigated agriculture production in the era of rapidly increasing stress on our natural resources require, among other essential actions, optimum control and management of the applied water. Thus, a significant upgrade of the currently available soil water monitoring technologies is needed. The primary goal of...
Contamination of ground water by non-aqueous phase liquids (NAPLs) has
received increasing attention. The most common approach to numerical modeling of
NAPL movement through the unsaturated zone is the use of the finite difference or finite
element methods to solve a set of partial differential equations derived from Darcy's law...
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...