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Articles 301 - 330 of 338

Full-Text Articles in Fresh Water Studies

A System For Estimating Bowen Ratio And Evaporation From Waste Lagoons, Arturo I. Quintanar, Rezaul Mahmood, John H. Loughrin, Nanh Lovanh, Monica V. Motley Jan 2009

A System For Estimating Bowen Ratio And Evaporation From Waste Lagoons, Arturo I. Quintanar, Rezaul Mahmood, John H. Loughrin, Nanh Lovanh, Monica V. Motley

High Plains Regional Climate Center: Staff Publications

A low‐cost system was deployed above a swine waste lagoon to obtain estimates of Bowen ratios and characterize lagoon temperatures. The system consisted of humidity and temperature sensors and anemometers deployed above the lagoon, water temperature sensors, and a meteorological station located by the lagoon. To evaluate the system, data was analyzed from the 25th through 28th June 2007. Bowen ratios showed diurnal behavior near the lagoon surface characterized by negative values during day and positive ones at night. Latent (evaporation) and sensible heat fluxes were towards the atmosphere and the lagoon, respectively for most of the day. A diurnal …


Droughtscape, Winter 2009, Kelly Smith Jan 2009

Droughtscape, Winter 2009, Kelly Smith

DroughtScape: Quarterly Newsletter of the National Drought Mitigation Center (2007–2023)

Bastrop TX: Feb. 12 Central CA: Feb. 24, 26

La Niña May Keep West and Gulf Coast Dry

Big Canoes to Launch

2008 in Review

U.S. Feels Drought Impacts in 2008

NDMC Welcomes Widhalm, Sakamoto

Climate Modelers at Workshop Look to Sea Surface Temperatures for Drought Prediction


Ecosystem Jenga!, Natalie Umphlett, Tierney Brosius, Ramesh Laungani, Diandra L. Leslie-Pelecky Jan 2009

Ecosystem Jenga!, Natalie Umphlett, Tierney Brosius, Ramesh Laungani, Diandra L. Leslie-Pelecky

High Plains Regional Climate Center: Staff Publications

Students are often taught that ecosystems are "delicately balanced," But what. exactly, does this mean? How do we help students relate what they learn in the classroom about ecosystems to the world immediately around them?

As scientists who work closely with middle school students as part of a National Science Foundation-funded Graduate Fellows in K-12 Education program called Project Fulcrum. we have learned that abstract concepts, such as "delicately balanced ecosystem," are often not truly understood. We addressed this concern in a seventh-grade science classroom in Lincoln. Nebraska. by introducing students to locally threatened saline wetlands and the endangered Salt …


Droughtscape, Fall 2008, Kelly Smith Oct 2008

Droughtscape, Fall 2008, Kelly Smith

DroughtScape: Quarterly Newsletter of the National Drought Mitigation Center (2007–2023)

Washington Workshops Scheduled for November

Look for Warm West, Rainy Gulf, Easing Drought

New Drought Monitor Authors Profiled

Drought Impact Awareness Growing: Weather Forecast Offices, Geographers Highlight Issue

NDMC Takes on New Projects

Hundreds+ See NDMC at Ag Trade Show

NDMC Welcomes New Employees


Droughtscape, Fall 2008, Kelly Smith Oct 2008

Droughtscape, Fall 2008, Kelly Smith

DroughtScape: Quarterly Newsletter of the National Drought Mitigation Center (2007–2023)

Washington Workshops Scheduled for November

Look for Warm West, Rainy Gulf, Easing Drought

New Drought Monitor Authors Profiled

Drought Impact Awareness Growing: Weather Forecast Offices, Geographers Highlight Issue

NDMC Takes on New Projects

Hundreds+ See NDMC at Ag Trade Show

NDMC Welcomes New Employees


Droughtscape, Summer 2008, Kelly Smith Jul 2008

Droughtscape, Summer 2008, Kelly Smith

DroughtScape: Quarterly Newsletter of the National Drought Mitigation Center (2007–2023)

VegDRI Expands West

Spring Rains Ease Drought But CA Still Dry

Scholar Donates Books

NDMC Welcomes Employees Bathke, Nothwehr

Latest Workshop Info Up

State Lawmakers to Focus on Drought Planning

Decadal Variation -- Clues to Droughts and Floods?


Droughtscape, Spring 2008, Kelly Smith Apr 2008

Droughtscape, Spring 2008, Kelly Smith

DroughtScape: Quarterly Newsletter of the National Drought Mitigation Center (2007–2023)

San Angelo, April 24

Winter Sees Little Change in U.S. Drought

News Stories Reveal Array of Mitigation Strategies

NIDIS Wants You!

Sea Surface Temperatures Can Help Predict Drought

About DroughtScape

Recent Travels


Testing A Simple Field Method For Assessing Nitrate Removal In Riparian Zones, Philippe Vidon, Michael G. Dosskey Apr 2008

Testing A Simple Field Method For Assessing Nitrate Removal In Riparian Zones, Philippe Vidon, Michael G. Dosskey

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Being able to identify riparian sites that function better for nitrate removal from groundwater is critical to using efficiently the riparian zones for water quality management. For this purpose, managers need a method that is quick, inexpensive, and accurate enough to enable effective management decisions. This study assesses the precision and accuracy of a simple method using three ground water wells and one measurement date for determining nitrate removal characteristics of riparian buffer zones. The method is a scaled-down version of a complex field research method that consists of a large network of wells and piezometers monitored monthly for over …


Sustainability In A Time Of Climate Change: Developing An Intensive Research Framework For The Platte River Basin And The High Plains Proceedings From The 2008 Climate Change Workshop, Monica Norby, Ashley Washburn Jan 2008

Sustainability In A Time Of Climate Change: Developing An Intensive Research Framework For The Platte River Basin And The High Plains Proceedings From The 2008 Climate Change Workshop, Monica Norby, Ashley Washburn

Office of Research and Economic Development: Publications

Proceedings from the 2008 Climate change Workshop, Nebraska Sandhills, May 19-22, 2008. Hosted by the University of Nebraska–Lincoln and the U.S. Geological Survey


Sampling Of Malodorous Compounds In Air Using Stir Bar Sorbtive Extraction, John H. Loughrin, Nanh Lovanh, Arturo I. Quintanar, Rezaul Mahmood Jan 2008

Sampling Of Malodorous Compounds In Air Using Stir Bar Sorbtive Extraction, John H. Loughrin, Nanh Lovanh, Arturo I. Quintanar, Rezaul Mahmood

High Plains Regional Climate Center: Staff Publications

Twisters, (poly)‐dimethylsiloxane‐coated magnetic stir bars, were used to measure compounds typical of swine manure malodor in air. In initial experiments, a time to achieve equilibrium was determined by preloading the stir bars with ten compounds with a range of volatilities and polarities and then monitoring their loss. The rate of loss was dependent on compound volatility, and the time for equilibrium to be attained varied widely, from 22 min for phenol to 210 min for skatole. To test whether the Twisters would respond linearly over a range of concentrations, the stir bars were placed in vented jars with solutions of …


Droughtscape, Winter 2008, Kelly Smith Jan 2008

Droughtscape, Winter 2008, Kelly Smith

DroughtScape: Quarterly Newsletter of the National Drought Mitigation Center (2007–2023)

Now Up & On-Line:

Winter 2008 Outlook and Oct.-Dec. ’07 Summary

NDMC Experts Serve as Resource for Media

Drought Hits Ag and Urban Interests in 2007

Climatological Summary of Drought in 2007

NDMC Welcomes Data Miner Bo Zhang

New Grant Awards


Floristic Records In The Platte And Loup River Bottomlands Of Platte County, Nebraska, Michael P. Gutzmer, Robert B. Kaul Jan 2008

Floristic Records In The Platte And Loup River Bottomlands Of Platte County, Nebraska, Michael P. Gutzmer, Robert B. Kaul

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

A recent inventory of vascular plants in the Loup and Platte riverbottoms in Platte County has greatly increased knowledge of the area's flora. Of the 542 species of vascular plants now known to grow in the county, 289 were discovered after 1977, with more than 100 of those after 1990. 425 native and 117 naturalized species are known so far. Nearly 700 native and naturalized alien species are expected to occur in the county, based upon totals from nearby counties. Thus, almost 150 years after European settlement, more than 20% of the species remain unverified; of those, many are undoubtedly …


Comparison Of Total Mercury And Methylmercury Cycling At Five Sites Using The Small Watershed Approach, James B. Shanley, M. Alisa Mast, Donald H. Campbell, George R. Aiken, David P. Krabbenhoft, Randall J. Hunt, John F. Walker, Paul F. Schuster, Ann Chalmers, Brent T. Aulenbach, Norman E. Peters, Mark Marvin-Dipasquale, David W. Clow, Martin M. Shafer Jan 2008

Comparison Of Total Mercury And Methylmercury Cycling At Five Sites Using The Small Watershed Approach, James B. Shanley, M. Alisa Mast, Donald H. Campbell, George R. Aiken, David P. Krabbenhoft, Randall J. Hunt, John F. Walker, Paul F. Schuster, Ann Chalmers, Brent T. Aulenbach, Norman E. Peters, Mark Marvin-Dipasquale, David W. Clow, Martin M. Shafer

United States Geological Survey: Staff Publications

The small watershed approach is well-suited but underutilized in mercury research. We applied the small watershed approach to investigate total mercury (THg) and methylmercury (MeHg) dynamics in streamwater at the five diverse forested headwater catchments of the US Geological Survey Water, Energy, and Biogeochemical Budgets (WEBB) program. At all sites, baseflow THg was generally less than 1 ng L-1 and MeHg was less than 0.2 ng L-1. THg and MeHg concentrations increased with streamflow, so export was primarily episodic. At three sites, THg and MeHg concentration and export were dominated by the particulate fraction in association with …


Droughtscape, Fall 2007, National Drought Mitigation Center Oct 2007

Droughtscape, Fall 2007, National Drought Mitigation Center

DroughtScape: Quarterly Newsletter of the National Drought Mitigation Center (2007–2023)

Fall 2007 Outlook

Diverse Impacts Reported in Summer of 2007

Decadal Climate Cycles Hold Predictive Potential

Drought Experts Take Roadmap to Congress

NDMC Research Updates


Droughtscape, Summer 2007, National Drought Mitigation Center Jul 2007

Droughtscape, Summer 2007, National Drought Mitigation Center

DroughtScape: Quarterly Newsletter of the National Drought Mitigation Center (2007–2023)

Summer 07 Outlook

Hayes Named Director of NDMC

NDMC & UN Plan for Drought

Book Review: The Worst Hard Time

Drought Tools Workshops Underway

U.S. Drought Monitor Forum October 10-11, 2007 Portland, Oregon


Droughtscape, Spring 2007, National Drought Mitigation Center Apr 2007

Droughtscape, Spring 2007, National Drought Mitigation Center

DroughtScape: Quarterly Newsletter of the National Drought Mitigation Center (2007–2023)

2007 Spring Drought Outlook & Winter Summary

VegDRI Expands to 15 States, Refines Views

DroughtScape

State Spotlight: Utah

International Panel Foresees Drought as Part of Climate Change

NIDIS Portal Advancing


Agricultural Climatology, Kenneth G. Hubbard Jan 2007

Agricultural Climatology, Kenneth G. Hubbard

High Plains Regional Climate Center: Staff Publications

With the diversification of the U.S. economy over the past century, agriculture has changed. We can say the farm sizes have increased over time, the number of farmers and those employed in farming have decreased over time, and as the economy has grown the relative contribution of agriculture to the total economy has decreased due to growth in other sectors. The farm prices have not changed significantly over many years while costs for energy, machinery, and land have generally increased. The combination of these factors has generally narrowed the profit margin and the highest productivity will no longer ensure the …


Droughtscape, Winter 2007, Kelly Smith Jan 2007

Droughtscape, Winter 2007, Kelly Smith

DroughtScape: Quarterly Newsletter of the National Drought Mitigation Center (2007–2023)

Subscribe Now!

Policy Update: NIDIS is Law. What’s Next?

What Would You Like to See?

TX, OK, Plains, Southwest Hardest Hit in 2006

Climatologically Speaking, How Bad Was It?

State Spotlight: Arizona

Drought Decision-Support Tools Evolving


Hydrologic Connectivity And The Contribution Of Stream Headwaters To Ecological Integrity At Regional Scales, Mary C. Freeman, Catherine M. Pringle, C. Rhett Jackson Jan 2007

Hydrologic Connectivity And The Contribution Of Stream Headwaters To Ecological Integrity At Regional Scales, Mary C. Freeman, Catherine M. Pringle, C. Rhett Jackson

United States Geological Survey: Staff Publications

Cumulatively, headwater streams contribute to maintaining hydrologic connectivity and ecosystem integrity at regional scales. Hydrologic connectivity is the water-mediated transport of matter, energy and organisms within or between elements of the hydrologic cycle. Headwater streams compose over two-thirds of total stream length in a typical river drainage and directly connect the upland and riparian landscape to the rest of the stream ecosystem. Altering headwater streams, e.g., by channelization, diversion through pipes, impoundment and burial, modifies fluxes between uplands and downstream river segments and eliminates distinctive habitats. The large-scale ecological effects of altering headwaters are amplified by land uses that alter …


Evaluation Of Habitat Enhancement Structure Use By Spotted Bass, Stanley L. Proboszcz, Christopher S. Guy Dec 2006

Evaluation Of Habitat Enhancement Structure Use By Spotted Bass, Stanley L. Proboszcz, Christopher S. Guy

The Prairie Naturalist

Habitat enhancement is a common and effective method used to positively influence fish populations. However, there is a paucity of speciesspecific evaluations of stream habitat enhancement structures for warmwater fishes. We evaluated use of half-log, rootwad enhancement structure, and simulated undercut bank (LUNKERS) by adult and juvenile spotted bass (Micropterus punctulatus) in natural and experimental streams. Enhancement structures were installed in Otter Creek, Kansas. Adult spotted bass use of natural and enhancement structure was documented weekly during summer and fall of 2001 and 2002 with radiotelemetry. Mean total length (TL) of adult fish was 292 mm (SE = …


Pond Production, Bartholomew W. Green, C. Bauer Duke Iii Jan 2006

Pond Production, Bartholomew W. Green, C. Bauer Duke Iii

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Management strategies for production of tilapia (Oreochromis sp.) in earthen or lined ponds range from chemical and/or organic fertilization only to intensive feeding. Pond water quality for each strategy is discussed. Strategies to optimize standing stock management during grow-out are presented.


The Composition Of Coexisting Jarosite-Group Minerals And Water From The Richmond Mine, Iron Mountain, California, Heather E. Jamieson, Clare Robinson, Charles N. Alpers, D. Kirk Nordstrom, Alexei Poustovetov, Heather A. Lowers Jan 2005

The Composition Of Coexisting Jarosite-Group Minerals And Water From The Richmond Mine, Iron Mountain, California, Heather E. Jamieson, Clare Robinson, Charles N. Alpers, D. Kirk Nordstrom, Alexei Poustovetov, Heather A. Lowers

United States Geological Survey: Staff Publications

Jarosite-group minerals accumulate in the form of stalactites and fine-grained mud on massive pyrite in the D drift of the Richmond mine, Iron Mountain, California. Water samples were collected by placing beakers under the dripping stalactites and by extracting pore water from the mud using a centrifuge. The water is rich in Fe3+ and SO42–, with a pH of approximately 2.1, which is significantly higher than the extremely acidic waters found elsewhere in the mine. Electron-microprobe analysis and X-ray mapping indicate that the small crystals (<10 > μm in diameter) are compositionally zoned with respect to Na …


A Watershed-Based Classification System For Lakes In Agriculturally-Dominated Ecosystems: A Case Study Of Nebraska Reservoirs, Henry N. N. Bulley Dec 2004

A Watershed-Based Classification System For Lakes In Agriculturally-Dominated Ecosystems: A Case Study Of Nebraska Reservoirs, Henry N. N. Bulley

Department of Geography: Dissertations, Theses, and Student Research

In recent decades substantial progress has been made in improving the quality of surface waters in the United States (Hawkins et al., 2000; EPA, 2000; EPA, 2001); nevertheless, much work remains to be done in assessing the state of impairment of lake waters. Impairment implies that the existing water quality of a lake, as measured by selected criteria (e.g., nitrogen, phosphorus, chlorophyll-a, Secchi depth), exceeds a threshold value or standard that presumably reflects optimal attainable lake water quality conditions (or "reference" conditions) (Hughes, 1995; EPA, 2000; EPA, 2001). Such impaired waters are not suitable for designated uses such as drinking, …


Ogallala Aquifer, Robert F. Diffendal Jr. Jan 2004

Ogallala Aquifer, Robert F. Diffendal Jr.

School of Natural Resources: Faculty Publications

The Ogallala Aquifer, or High Plains Aquifer, is a porous body of complex sediments and sedimentary rock formations that conducts groundwater and yields significant quantities of water to wells and springs. The principal sediments and rocks of the aquifer range in age from 33 million years old to sediments being deposited today, but the majority is less than 12 million-years old. Much of the aquifer is composed of the Ogallala Group or Formation. The dominant sediments in the Ogallala and the other hydrogeologic units in the aquifer are riverand wind-deposited sands. The aquifer underlies about 174,000 square miles of the …


An Analysis Of Simulated Long-Term Soil Moisture Data For Three Land Uses Under Contrasting Hydroclimatic Conditions In The Northern Great Plains, Rezaul Mamood, Kenneth G. Hubbard Jan 2004

An Analysis Of Simulated Long-Term Soil Moisture Data For Three Land Uses Under Contrasting Hydroclimatic Conditions In The Northern Great Plains, Rezaul Mamood, Kenneth G. Hubbard

High Plains Regional Climate Center: Staff Publications

Soil moisture (SM) plays an important role in land surface and atmosphere interactions. It modifies energy balance near the surface and the rate of water cycling between land and atmosphere. The lack of observed SM data prohibits understanding of SM variations at climate scales under varying land uses. However, with simulation models it is possible to develop a long-term SM dataset and study these issues. In this paper a water balance model is used to provide a quantitative assessment of SM climatologies for three land uses, namely, irrigated corn, rain-fed corn, and grass, grown under three hydroclimatic regimes in Nebraska. …


Field Guide To The Geology Of The Harlan County Lake Area, Harlan County, Nebraska, With A History Of Events Leading To Construction Of Harlan County Dam, Robert F. Diffendal Jr., Duane R. Mohlman, R. George Corner, F. Edwin Harvey, K. J. Warren, Scott Summerside, Roger K. Pabian, Duane A. Eversoll Aug 2002

Field Guide To The Geology Of The Harlan County Lake Area, Harlan County, Nebraska, With A History Of Events Leading To Construction Of Harlan County Dam, Robert F. Diffendal Jr., Duane R. Mohlman, R. George Corner, F. Edwin Harvey, K. J. Warren, Scott Summerside, Roger K. Pabian, Duane A. Eversoll

School of Natural Resources: Faculty Publications

The year 2002 will mark the fiftieth anniversary of completion of the Harlan County Dam and Multi-Purpose Reservoir. This seems a good time to write about the history of and reasons for building the dam, the effects of the dam and reservoir on the Republican River valley, and the geologic features seen along the shores of the lake and areas nearby. As many junior authors helped produced this educational circular, they are listed in the table of contents. All other sections were written by the senior author.

Includes July 2016 update: Addendum of photographs showing fault traces on drought-exposed lake …


Land Use Change And Modification Of Near-Surface Thermal Records In The Northern Great Plains, Rezaul Mahmood, Ken Hubbard, Christy Carlson Jan 2002

Land Use Change And Modification Of Near-Surface Thermal Records In The Northern Great Plains, Rezaul Mahmood, Ken Hubbard, Christy Carlson

High Plains Regional Climate Center: Staff Publications

The North American Great Plains have experienced a rapid overturning of natural grasslands to agricultural land use over the last century. Moreover, in some areas more than 80% of the land use has changed from dry land to irrigated agriculture during the second half of the twentieth century. It is speculated that these changes have modified near-surface atmospheric condition and our modeling study seems to support this. To identify changes in land surface- atmospheric modifications we have applied a soil moistureenergy balance model at three locations in Nebraska: Mead, York, and McCook. The model was applied for three land uses …


Age Of Ground Water At City Of Lincoln's Municipal Well Field Near Ashland, Nebraska, Gregory V. Steele Jan 2002

Age Of Ground Water At City Of Lincoln's Municipal Well Field Near Ashland, Nebraska, Gregory V. Steele

United States Geological Survey: Water Reports and Publications

The Platte River alluvial aquifer, which underlies the Plaue River Valley, is an important source of water for public supply in central and eastern Nebraska. Knowing the age of ground water can help scientists and water managers better understand the dynamics of the groundwater system. In turn, this knowledge will help in calibrating groundwater-flow models and aid in developing a conceptual understanding of how long it takes for recharge water to reach certain areas of the aquifer. Although previous studies (Davis, 1992; Steele and Verstraeten, 1999; Verstraeten et al., 1999) reported the interaction of surface water and ground water at …


Evaluation Of Nile Tilapia Pond Management Strategies In Egypt, Bartholomew W. Green, Zenab El Nagdy, Hussein Hebicha Jan 2002

Evaluation Of Nile Tilapia Pond Management Strategies In Egypt, Bartholomew W. Green, Zenab El Nagdy, Hussein Hebicha

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Five pond management strategies for Nile tilapia (Oreochromis niloticus L.) production were evaluated in 0.1-ha earthen ponds in Egypt during a 145-day production cycle. Pond management strategies developed by the Pond Dynamics/Aquaculture Collaborative Research Support Program (PD/A CRSP) were compared to a traditional and to a modified Egyptian pond management strategy. Young-of-year Nile (mixed-sex or sex-reversed) tilapia were stocked into ponds at 20,000 fish ha-1. Sex-reversed tilapia were stocked into chemical fertilization, organic fertilization plus formulated feed, and feed only treatment ponds, while mixed-sex tilapia were stocked into organic fertilization plus formulated feed, and chemical plus organic …


Drought In The United States: 1996 Summary And Historical Perspective, William O. Brown, Richard R. Heim Jr. Feb 1997

Drought In The United States: 1996 Summary And Historical Perspective, William O. Brown, Richard R. Heim Jr.

Drought Network News (1994–2001)

Considerable variation in moisture conditions, on both a spatial and temporal basis, occurred in the contiguous United States during 1996. A tenth or more of the country experienced severe to extreme short-term (i.e., monthly) precipitation deficits during nearly half of the months, but in many months there were also large areas of excessive precipitation, which resulted in overall national conditions averaging near normal to wetter than normal. From a national perspective, long-term drought peaked at mid-year, when severe drought plagued the South and Southwest.