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Articles 1981 - 2010 of 5272

Full-Text Articles in Hydrology

New Tools For Assessing Drought Conditions For Rangeland Management, Cody Knutson, Brian Fuchs Jan 2016

New Tools For Assessing Drought Conditions For Rangeland Management, Cody Knutson, Brian Fuchs

National Drought Mitigation Center: Faculty Publications

Historical drought assessment and ongoingmonitoring is essential for understanding past drought occurrence, the relationships between past drought and its impacts, and for triggering action during current drought events. • A variety of new products have recently been developed to better monitor drought conditions and assess past occurrences at the local scale. • A growing number of resources are available to assist rangeland managers to develop a monitoring system and incorporate it into a drought management plan.


Geochemical Processes And Controls Affecting Water Quality Of The Karst Area Of Big Creek Near Mt. Judea, Arkansas, V. Brahana, J. Nix, C. Kuyper, T. Turk, F. Usrey, S. Hodges, C. Bitting, K. Ficco, E. Pollock, R. Quick, B. Thompson, J. Murdoch Jan 2016

Geochemical Processes And Controls Affecting Water Quality Of The Karst Area Of Big Creek Near Mt. Judea, Arkansas, V. Brahana, J. Nix, C. Kuyper, T. Turk, F. Usrey, S. Hodges, C. Bitting, K. Ficco, E. Pollock, R. Quick, B. Thompson, J. Murdoch

Journal of the Arkansas Academy of Science

Karst regions typically are considered to be vulnerable with respect to various land-use activities, owing to the intimate association of surface and groundwater and lack of contaminant attenuation provided by most karst aquifers. Inasmuch as the soluble rocks of the karst landscape can be dissolved to create large, rapid-flow zones that compete successfully with surface streams, groundwater and subsurface flow represent a much larger component of the hydrologic budget in karst regions than in areas where non-soluble rocks predominate. Karst areas typically are distinguished by being unique, but some general approaches can be applied to characterize the hydrology of the …


Lower Mississippian Chert Development, Southern Midcontinent Region, J. M. Cains, A. Potra, E. D. Pollock Jan 2016

Lower Mississippian Chert Development, Southern Midcontinent Region, J. M. Cains, A. Potra, E. D. Pollock

Journal of the Arkansas Academy of Science

The Lower Mississippian Boone Formation is a chert-bearing, fossiliferous limestone typically 100-115m. thick forming the Springfield Plateau across the tri-state region of northwestern Arkansas, southwestern Missouri, and northeastern Oklahoma. The Boone represents the maximum flooding, highstand, and regressive intervals of a single, third order transgressive-regressive carbonate cycle bounded by regional unconformities. Two types of chert occur in this formation, and provide the basis for subdivision of the Boone into informal lower and upper members in northern Arkansas. The lower Boone represents early Osagean maximum flooding conditions and consists of calcisiltites with interbedded dark, nodular chert. This chert exhibits compaction phenomena …


The Life Cycle Of Dams: An Analysis Of Policy Change On The Rogue River, Oregon, Wendy Mcdermott Jan 2016

The Life Cycle Of Dams: An Analysis Of Policy Change On The Rogue River, Oregon, Wendy Mcdermott

All Master's Theses

Every river system contains a unique set of attributes including biophysical characteristics, human created infrastructure, and stakeholder user groups. This thesis utilizes Lowry’s (2003) “Theoretical Framework for Policy Changes” to provide an analysis of fundamental policy change that occurred on the Rogue River in southwest Oregon through a comparative case study of the removal of two dams: Savage Rapids Dam (SRD) and the Gold Ray Dam (GRD). Fundamental change occurs when political receptivity is high and physical complexity is low. Political receptivity characterizes how decisions are made and physical complexity refers to how complicated implementing the decision may be. Application …


Remobilization Of Cobalt, Copper, Nickel, Lead, And Zinc In A Riparian Wetland Model, Richard Glenn Dolly Jan 2016

Remobilization Of Cobalt, Copper, Nickel, Lead, And Zinc In A Riparian Wetland Model, Richard Glenn Dolly

Electronic Theses and Dissertations

The mobility of chemically persistent metals in riparian wetland systems that could have a detrimental impact on the environment is an area of active research. This study utilized a physical model consisting of open water and wetland cells designed to simulate a natural riparian wetland to examine the mobility of five metals. The objective of the study was to determine if riparian wetlands have the potential to serve as permanent sinks for metals, or if they only serve as temporary sinks and with time metals could be remobilized and released. Specifically, this study examined the long-term behavior of Co, Cu, …


Temporal Variations Of Streamflow In A Mid-Latitude Eurasian Steppe Watershed In The Past Half Century, Xixi Wang Jan 2016

Temporal Variations Of Streamflow In A Mid-Latitude Eurasian Steppe Watershed In The Past Half Century, Xixi Wang

Civil & Environmental Engineering Faculty Publications

Previous studies either did not identify abrupt change or identified such change but did not exclude it from the detection of trend in streamflow. As a result, an overall downward trend might be erroneously detected as an upward trend because of abrupt increase, while an overall upward trend could be faked as a downward trend due to abrupt decrease. The objectives of this study were to: (1) present a methodology to analyze trend in streamflow in the presence of abrupt change; and (2) use this methodology to detect trend and extreme occurrence of streamflow in the Upper Balagaer River watershed, …


Synthesis Of Satellite Microwave Observations For Monitoring Global Land-Atmosphere Co2 Exchange, Lucas Alan Jones Jan 2016

Synthesis Of Satellite Microwave Observations For Monitoring Global Land-Atmosphere Co2 Exchange, Lucas Alan Jones

Graduate Student Theses, Dissertations, & Professional Papers

This dissertation describes the estimation, error quantification, and incorporation of land surface information from microwave satellite remote sensing for modeling global ecosystem land-atmosphere net CO2 exchange. Retrieval algorithms were developed for estimating soil moisture, surface water, surface temperature, and vegetation phenology from microwave imagery timeseries. Soil moisture retrievals were merged with model-based soil moisture estimates and incorporated into a light-use efficiency model for vegetation productivity coupled to a soil decomposition model. Results, including state and uncertainty estimates, were evaluated with a global eddy covariance flux tower network and other independent global model- and remote-sensing based products.


Modeling Spring Catchment Discharge: A Case Study Of Candela, Panama, Central America, Jordan P. Van Sickle Jan 2016

Modeling Spring Catchment Discharge: A Case Study Of Candela, Panama, Central America, Jordan P. Van Sickle

Dissertations, Master's Theses and Master's Reports

Where the proper geological and hydrological conditions exist, natural springs have provided a reliable source of clean water to mankind for eons. Changing climates and land development can negatively impact spring source replenishment and threaten their reliability as a source of water. In the face of prospects of diminishing supplies and increasing population demands, community leaders question whether and how to invest in development for enhancing sustainability and protecting water quality, causing water managers to dispute their reliability given decreasing flows. Springs located in the rugged jungle of western Panama serve as the primary water supply for many indigenous communities, …


Late Glacial And Holocene History Of The Penobscot River In The Penobscot Lowland, Maine, Roger Leb. Hooke, Paul R. Hanson, Danile F. Belknap, Alice R. Kelley Jan 2016

Late Glacial And Holocene History Of The Penobscot River In The Penobscot Lowland, Maine, Roger Leb. Hooke, Paul R. Hanson, Danile F. Belknap, Alice R. Kelley

Conservation and Survey Division: Faculty and Staff Publications

When the Laurentide ice sheet retreated rapidly (~150 m/a) across the Penobscot Lowland between ~16 and ~15 ka, the area was isostatically depressed and became inundated by the sea. Silt and clay were deposited, but no significant moraines or deltas were formed. The Penobscot River was reborn at ~14 ka when ice retreated onto land in the upper reaches of the river’s East Branch. As isostatic rebound exceeded sea level rise from melting ice, the river extended itself southward. Between ~13.4 and 12.8 ka, it established a course across marine clay and underlying glacial till in the Lowland. Its gradient …


Seasonal Evolution Of Active Layer Formation In Subarctic Peat Plateaux And Implications For Dissolved Organic Matter Composition And Transfer, Jennifer L. Hickman Jan 2016

Seasonal Evolution Of Active Layer Formation In Subarctic Peat Plateaux And Implications For Dissolved Organic Matter Composition And Transfer, Jennifer L. Hickman

Theses and Dissertations (Comprehensive)

Peat-accumulating wetlands are ecosystems whose rate of photosynthetic production of organic matter is greater than that of its decomposition, resulting in a build up of soil organic matter that may take centuries to fully decompose. Carbon (C) stocks within these ecosystems are a function of inputs from photosynthesis, and losses from heterotrophic decomposition. Due to the short growing season and overall cold climate of boreal and tundra regions, C has been accumulating within these landscapes, mostly in soil organic matter, since the last glaciation. Climate change, predicted to result in rising temperatures and increased precipitation, has begun to degrade the …


Partitioning Evapotranspiration In Forested Peatlands Within The Western Boreal Plain, Fort Mcmurray, Alberta, Canada, Elise C. Gabrielli Jan 2016

Partitioning Evapotranspiration In Forested Peatlands Within The Western Boreal Plain, Fort Mcmurray, Alberta, Canada, Elise C. Gabrielli

Theses and Dissertations (Comprehensive)

Forested peatlands in the Western Boreal Plain (WBP) represent hydrologically sensitive ecosystems that often support an open-crown forest of Picea mariana and/or Larix laricina. These systems store globally significant soil carbon, containing one-fourth to one-third of the world’s soil organic carbon pool (Turunen et al., 2002),serving a critical role in regulating atmospheric CO2. Recent studies indicate that the hydrological conditions are the critical determinant of a peatland’s carbon budget (Price et al., 2005; Aurela et al., 2007).To understand current hydrological conditions, it is essential to accurately estimate the rate of ET, due …


Optical Properties And Bioavailability Of Dissolved Organic Matter Along A Flow-Path Continuum From Soil Pore Waters To The Kolyma River Mainstem, East Siberia, Karen E. Frey, William V. Sobczak, Paul J. Mann, Robert M. Holmes Jan 2016

Optical Properties And Bioavailability Of Dissolved Organic Matter Along A Flow-Path Continuum From Soil Pore Waters To The Kolyma River Mainstem, East Siberia, Karen E. Frey, William V. Sobczak, Paul J. Mann, Robert M. Holmes

Geography

The Kolyma River in northeast Siberia is among the six largest Arctic rivers and drains a region underlain by vast deposits of Holocene-aged peat and Pleistocene-aged loess known as yedoma, most of which is currently stored in ice-rich permafrost throughout the region. These peat and yedoma deposits are important sources of dissolved organic matter (DOM) to inland waters that in turn play a significant role in the transport and ultimate remineralization of organic carbon to CO2 and CH4 along the terrestrial flow-path continuum. The turnover and fate of terrigenous DOM during offshore transport largely depends upon the composition and amount …


Variation In Summer Nitrogen And Phosphorus Uptake Among Siberian Headwater Streams, John D. Schade, Erin C. Seybold, Travis Drake, Seth Spawn, William V. Sobczak, Karen E. Frey, Robert M. Holmes, Nikita Zimov Jan 2016

Variation In Summer Nitrogen And Phosphorus Uptake Among Siberian Headwater Streams, John D. Schade, Erin C. Seybold, Travis Drake, Seth Spawn, William V. Sobczak, Karen E. Frey, Robert M. Holmes, Nikita Zimov

Geography

Arctic streams are likely to receive increased inputs of dissolved nutrients and organic matter from thawing permafrost as climate warms. Documenting how Arctic streams process inorganic nutrients is necessary to understand mechanisms that regulate watershed fluxes of permafrost-derived materials to downstream ecosystems. We report on summer nitrogen (N) and phosphorus (P) uptake in streams draining upland soils from the Pleistocene, and lowland floodplain soils from the Holocene, in Siberia's Kolyma River watershed. Uptake of N and P differed between upland and floodplain streams, suggesting topographic variation in nutrient limitation. In floodplain streams, P uptake rate and uptake velocity were higher …


Hydrological Drought Analysis For Seven North Georgia Watersheds (1970-2000), Jessica L. Taylor Jan 2016

Hydrological Drought Analysis For Seven North Georgia Watersheds (1970-2000), Jessica L. Taylor

Theses and Dissertations

Drought is a prolonged reduction in precipitation which may result in significant effects on local ecosystems, watersheds, and water sources, with the potential to have negative impacts on human populations. Normalized indexes can be used to characterize drought magnitudes and frequencies using historical data records on temperature, rainfall, snowpack, soil moisture, streamflow, and/or other water supply indicators. This study examined the applicability of two drought indices: Standardized Precipitation Index (SPI) and Streamflow Drought Index (SDI). The SPI and SDI estimate the magnitude of observed rainfall (SPI) and discharge (SDI) deviations from the long-term average.

In this study, SPI and SDI …


U.S. Drought Monitor, December 22, 2015, Richard R. Heim Jr. Dec 2015

U.S. Drought Monitor, December 22, 2015, Richard R. Heim Jr.

United States Agricultural Commodities in Drought Archive

Drought map of the United States for December 22, 2015 (12/22/15) plus: United States crop areas experiencing drought (map), an approximate percentage of crop located in drought by state (bar graph), and the percentage of crop area located in drought during the past 52 weeks (line graph) for corn, soybeans, hay, cattle, and winter wheat.


Response Of Fishes To Restoration Projects In Bayou St. John Located Within The City Of New Orleans, Louisiana, Including Hydrological Characterization And Hydrodynamic Modelling, Patrick W. Smith Dec 2015

Response Of Fishes To Restoration Projects In Bayou St. John Located Within The City Of New Orleans, Louisiana, Including Hydrological Characterization And Hydrodynamic Modelling, Patrick W. Smith

LSU New Orleans Theses and Dissertations

Quantifying the impacts of restoration on coastal waterways is crucial to understanding their effectiveness. Here, I look at the impacts of multiple restoration projects on urban waterways within the city limits of New Orleans, LA, with an emphasis on the response of fishes. First I report the effects of two projects designed to improve exchange down estuary on the hydrologic characteristics of Bayou St. John (BSJ). Within BSJ, flow is dominated by subtidal wind driven processes. Removal of an outdated flood control structure did not appear to alter exchange in BSJ, but removal combined with sector gate openings did. I …


Linear Trend Detection In Serially Dependent Hydrometeorological Data Based On A Variance Correction Spearman Rho Method, Wenpeng Weng, Yuanfang Chen, Stefan Becker, Bo Liu Dec 2015

Linear Trend Detection In Serially Dependent Hydrometeorological Data Based On A Variance Correction Spearman Rho Method, Wenpeng Weng, Yuanfang Chen, Stefan Becker, Bo Liu

Publications and Research

Hydrometeorological data are commonly serially dependent and thereby deviate from the assumption of independence that underlies the Spearman rho trend test. The presence of autocorrelation will influence the significance of observed trends. Specifically, the positive autocorrelation inflates Type І errors, while it deflates the power of trend detection in some cases. To address this issue, we derive a theoretical formula and recommend an appropriate empirical formula to calculate the rho variance of dependent series. The proposed procedure of the variance correction for the Spearman rho method is capable of mitigating the effect of autocorrelation on both, Type І error and …


U.S. Drought Monitor, December 15, 2015, Richard Tinker Dec 2015

U.S. Drought Monitor, December 15, 2015, Richard Tinker

United States Agricultural Commodities in Drought Archive

Drought map of U.S. for December 15, 2015 (12/15/15) plus: U.S. crop areas experiencing drought (map), Approximate percentage of crop located in drought, by state (bar graph), Percent of crop area located in drought, past 52 weeks (line graph) for: Corn, Soybeans, Hay, Cattle, Winter wheat.


The Force Of Water: Columbia After The Flood, Rebecca Johnson Dec 2015

The Force Of Water: Columbia After The Flood, Rebecca Johnson

Senior Theses

Nearly two months have passed, and South Carolina is still recovering from the unprecedented inundation of rain that pelted down in early October. Record amounts of precipitation pounded the state over just a few days, resulting in the flooding and erosion of land, the deterioration of public infrastructure and the loss of human life and capital.

The worst of it was in the capital city. Columbia recorded the highest water levels and the highest number of fatalities of all the affected areas. The city’s utilities could not handle the torrent of water: dams were destroyed, canals were compromised, roads were …


An Investigation Of The Effects Of Chemical And Physical Weathering On Submerged Karst Surfaces, Bryan Charles Booth Dec 2015

An Investigation Of The Effects Of Chemical And Physical Weathering On Submerged Karst Surfaces, Bryan Charles Booth

USF Tampa Graduate Theses and Dissertations

Reports an investigation of the effects of chemical and physical weathering on submerged karst surfaces that pairs laboratory studies with computer modeling studies. The first study attempts to quantify the production of carbonate fines; soluble sediments produced by the incomplete dissolution of karst minerals during chemical weathering. Results show carbonate fine production in relation to dissolutional action; Chalk: 42.8%; Coquina: 2.6%; Dolomite: 3.1%; Gray Limestone: 4.8%; Ocala Limestone: 3.1%; Shell Limestone: 6.1%; Travertine: 8.6%. Due to the use of hydrochloric acid as opposed to carbonic acid these results may not be fully valid for application to natural speleogenic processes. The …


Umphlett Qci 2015, Natalie A. Umphlett Dec 2015

Umphlett Qci 2015, Natalie A. Umphlett

High Plains Regional Climate Center: Staff Publications

Highlights for the Basin

Temperature and Precipitation Anomalies

Late Hard Freeze

Late Freezes Extended Growing Season

Warm Fall Delays Bird Migrations

Monitoring Water Resources Across the Basin

3-Month Precipitation and Temperature Outlooks


Nebraska's Public Access Hunting Program: Hunter Preferences And Usage Final Report, Lisa Pennisi, Mark E. Burbach, Namyun Kil, Muhammed Imran Kahn, Andrew J. Tyre Dec 2015

Nebraska's Public Access Hunting Program: Hunter Preferences And Usage Final Report, Lisa Pennisi, Mark E. Burbach, Namyun Kil, Muhammed Imran Kahn, Andrew J. Tyre

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Deep Fluid Inputs Into The Continental-Scale Nubian Sandstone Aquifer System Constrained By Hydrochemical, Stable Isotope, And Noble Gas Data, Abdel Mawgoud Mohammed Dec 2015

Deep Fluid Inputs Into The Continental-Scale Nubian Sandstone Aquifer System Constrained By Hydrochemical, Stable Isotope, And Noble Gas Data, Abdel Mawgoud Mohammed

Dissertations

The Nubian Sandstone Aquifer System (NSAS) of northeastern Africa is one of the largest confined fossil-water aquifer systems in the world, with several nations relying on it (Egypt, Libya, Sudan and Chad). This groundwater is the biggest and in some cases the only future source of water to meet the development goals of each NSAS country. This study provides new geochemical data from the main oases of the Western Desert of Egypt and a compilation of published hydrochemical data from the regional aquifer. Interpretation of results suggests heterogeneous fluid mixing within the aquifer, the potential for hydrochemical sub-basins, and a …


Hydrology-Biology Response Relationships In The Ozark Highlands, Dustin Thomas Lynch Dec 2015

Hydrology-Biology Response Relationships In The Ozark Highlands, Dustin Thomas Lynch

Graduate Theses and Dissertations

I examined flow-ecology relationships among stream communities in the Ozark Highlands, USA. I sampled fish, crayfish, and benthic macroinvertebrates during two consecutive summers, including a drought year (2012) and a flood year (2013). Biological response variables related to community structure were assessed via two different statistical methods: an Information Theoretic approach relating response variables to a priori selected predictor variables incorporating hydrology, habitat, geomorphology, and water quality, and canonical ordination using forward selection to relate these same response variables to a large assortment of hydrologic metrics. In addition to assessing metrics related to predicted natural flow, flow alteration at gaged …


Estimation Of Deep Drainage Differences Between Till And No-Till Irrigated Agriculture, Justin P. Gibson Dec 2015

Estimation Of Deep Drainage Differences Between Till And No-Till Irrigated Agriculture, Justin P. Gibson

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Deep drainage was monitored under two center pivot irrigation sites located in south-central Nebraska during the 2013, and part of the 2014, growing seasons. Both fields underwent similar land management except for tillage practice: no-till in one and disk till in the other. Long term deep drainage rates were also estimated from chemical analysis of extracted soil cores, with the aid of the chloride mass balance equation. Mechanisms underpinning differences in deep drainage between the two fields were investigated through the use of unsaturated zone numerical modeling.

Deep drainage estimates from field monitoring indicated that a greater amount of deep …


Soft-Sediment Deformation And Dune Collapse In The Navajo Sandstone, Colby Ford Dec 2015

Soft-Sediment Deformation And Dune Collapse In The Navajo Sandstone, Colby Ford

Loma Linda University Electronic Theses, Dissertations & Projects

The Canyon Overlook Trail of Zion National Park follows an outcrop of Navajo Sandstone, which displays a uniquely well-exposed assemblage of features associated with failure of the lee face of a large eolian dune, and run-out over an expanse of interdune sediments downwind of that bedform. Exposed features include dramatic folds in the interdune succession and a stacked series of thrust sheets incorporating both interdune and overlying dune deposits. Thrust surfaces display consistent strikes, parallel to those of undeformed foresets, and incorporate zones of brittle failure and fluid deformation, including folds overturned in the direction of foreset dip. These features …


Exploring, Exploiting And Evolving Diversity Of Aquatic Ecosystem Models: A Community Perspective, Annette B.G. Janssen, George B. Arhonditsis, Arthur Beusen, Karsten Bolding, Louise Bruce, Jorn Bruggeman, Raoul-Marie Couture, Andrea S. Downing, J. Alex Elliott, Marieke A. Frassl, Gideon Gal, Daan J. Gerla, Matthew R. Hipsey, Fenjuan Hu, Stephen C. Ives, Jan H. Janse, Erik Jeppesen, Klaus D. Jöhnk, David Kneis, Xiangzhen Kong, Jan J. Kuiper, Moritz K. Lehmann, Carsten Lemmen, Deniz Özkundakci, Thomas Petzoldt, Karsten Rinke, Barbara J. Robson, René Sachse, Sebastiaan A. Schep, Martin Schmid, Huub Scholten, Sven Teurlincx, Dennis Trolle, Tineke A. Troost, Anne A. Van Dam, Luuk P.A. Van Gerven, Mariska Weijerman, Scott A. Wells, Wolf M. Mooij Dec 2015

Exploring, Exploiting And Evolving Diversity Of Aquatic Ecosystem Models: A Community Perspective, Annette B.G. Janssen, George B. Arhonditsis, Arthur Beusen, Karsten Bolding, Louise Bruce, Jorn Bruggeman, Raoul-Marie Couture, Andrea S. Downing, J. Alex Elliott, Marieke A. Frassl, Gideon Gal, Daan J. Gerla, Matthew R. Hipsey, Fenjuan Hu, Stephen C. Ives, Jan H. Janse, Erik Jeppesen, Klaus D. Jöhnk, David Kneis, Xiangzhen Kong, Jan J. Kuiper, Moritz K. Lehmann, Carsten Lemmen, Deniz Özkundakci, Thomas Petzoldt, Karsten Rinke, Barbara J. Robson, René Sachse, Sebastiaan A. Schep, Martin Schmid, Huub Scholten, Sven Teurlincx, Dennis Trolle, Tineke A. Troost, Anne A. Van Dam, Luuk P.A. Van Gerven, Mariska Weijerman, Scott A. Wells, Wolf M. Mooij

Civil and Environmental Engineering Faculty Publications and Presentations

Here, we present a community perspective on how to explore, exploit and evolve the diversity in aquatic ecosystem models. These models play an important role in understanding the functioning of aquatic ecosystems, filling in observation gaps and developing effective strategies for water quality management. In this spirit, numerous models have been developed since the 1970s. We set off to explore model diversity by making an inventory among 42 aquatic ecosystem modellers, by categorizing the resulting set of models and by analysing them for diversity. We then focus on how to exploit model diversity by comparing and combining different aspects of …


Rewetting Of Artificially Desiccated Soils: Effect Of Gravity On Vapor-Phase Diffusion, Taylor Arland Ball Dec 2015

Rewetting Of Artificially Desiccated Soils: Effect Of Gravity On Vapor-Phase Diffusion, Taylor Arland Ball

UNLV Theses, Dissertations, Professional Papers, and Capstones

Soil desiccation has been suggested as an economically viable alternative for stabilizing water soluble contaminants in deep vadose zones such as at the Hanford Site. This approach would result in a large volume of the vadose zone being dried out in an effort to eliminate the transport mechanism for aqueous phase contaminants. Protecting the top and sides of the desiccated vadose zone from rewetting is a realistic possibility; however, it would be extremely difficult to restrict the upward migration of water from beneath the desiccated zone. One scenario related to the rewetting of the desiccated soil involves the upward migration …


Modified Polysulfone Nanofiltration Membrane Synthesis For Hydraulic Fracturing Water Recycle, Blake Alexander Johnson Dec 2015

Modified Polysulfone Nanofiltration Membrane Synthesis For Hydraulic Fracturing Water Recycle, Blake Alexander Johnson

Graduate Theses and Dissertations

The use of hydraulic fracturing has resulted in significant increases in the yield of oil and natural gas, as water pumped into wells at high pressure cracks the formations and releases the hydrocarbons that are locked in the rocks. This process has created large volumes of brackish water that is very difficult to process and is often disposed of into injection wells. Suspended solids and some dissolved solids are more readily removed, but the multivalent ions found in certain salts can precipitate in a well and complicate the reuse of flowback in future hydraulic fracturing operations.

Nanofiltration, a membrane separation …


U.S. Drought Monitor, November 24, 2015, Richard R. Heim Jr. Nov 2015

U.S. Drought Monitor, November 24, 2015, Richard R. Heim Jr.

United States Agricultural Commodities in Drought Archive

Drought map of the United States for November 24, 2015 (11/24/15) plus: United States crop areas experiencing drought (map), an approximate percentage of crop located in drought by state (bar graph), and the percentage of crop area located in drought during the past 52 weeks (line graph) for corn, soybeans, hay, cattle, and winter wheat.