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Full-Text Articles in Physical Sciences and Mathematics

Identification Of Groundwater Sources For Municipal Wells Using Geochemical Data On The Platte Alluvial Aquifer And Underlying Limestone At The Lincoln Water Well Field Near Ashland Nebraska, Juanita Cruz Torres Dec 2014

Identification Of Groundwater Sources For Municipal Wells Using Geochemical Data On The Platte Alluvial Aquifer And Underlying Limestone At The Lincoln Water Well Field Near Ashland Nebraska, Juanita Cruz Torres

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

Alluvial aquifer systems where pumping of municipal wells induces recharge from the adjacent river are the primary source of water for many cities. The city of Lincoln, NE has a primary water source in an alluvial aquifer adjacent to the Platte River. The Lincoln Water System manages the stream/aquifer system by using integrated models for a better understanding during periods of high stress such as a drought. The integrated models set the limestone aquifer as an impermeable boundary to understand the alluvial aquifer system without having a secondary water source. The limestone aquifer is permeable and the purpose of this …


Data-Driven Diagnostics Of Terrestrial Carbon Dynamics Over North America, Jingfeng Xiao, Scott V. Ollinger, Steve Frolking, George Hurtt, David Y. Hollinger, Kenneth J. Davis, Yude Pan, Xiaoyang Zhang, Feng Deng, Jiquan Chen, Dennis D. Baldocchi, Beverly E. Law, M. Altaf Arain, Ankur R. Desai, Andrew D. Richardson, Ge Sun, Brian Amiro, Hank Margolis, Lianhong Gu, Russell L. Scott, Peter D. Blanken, Andrew E. Suyker Jan 2014

Data-Driven Diagnostics Of Terrestrial Carbon Dynamics Over North America, Jingfeng Xiao, Scott V. Ollinger, Steve Frolking, George Hurtt, David Y. Hollinger, Kenneth J. Davis, Yude Pan, Xiaoyang Zhang, Feng Deng, Jiquan Chen, Dennis D. Baldocchi, Beverly E. Law, M. Altaf Arain, Ankur R. Desai, Andrew D. Richardson, Ge Sun, Brian Amiro, Hank Margolis, Lianhong Gu, Russell L. Scott, Peter D. Blanken, Andrew E. Suyker

School of Natural Resources: Faculty Publications

The exchange of carbon dioxide is a key measure of ecosystem metabolism and a critical intersection between the terrestrial biosphere and the Earth’s climate. Despite the general agreement that the terrestrial ecosystems in North America provide a sizeable carbon sink, the size and distribution of the sink remain uncertain. We use a data-driven approach to upscale eddy covariance flux observations from towers to the continental scale by integrating flux observations, meteorology, stand age,aboveground biomass, and a proxy for canopy nitrogen concentrations from AmeriFlux and Fluxnet-Canada Research Network as well as a variety of satellite data streams from the MODIS sensors. …


On Target For People And Planet: Setting And Achieving Water-Related Sustainable Development Goals, Julie Van Der Bliek, Peter G. Mccornick, James Clarke Jan 2014

On Target For People And Planet: Setting And Achieving Water-Related Sustainable Development Goals, Julie Van Der Bliek, Peter G. Mccornick, James Clarke

Daugherty Water for Food Global Institute: Faculty Publications

Our specific focus in this book is on securing water for sustainable food production. This links to sustainable water resources management, delivering on the water supply and sanitation requirements and provisioning water for energy and the urban sector. A specific intent is to ensure that the realities in low- and middle-income countries in Africa and Asia are recognized and to provide practical pathways to change that fit these realities and the aspirations of those countries. This will help to prepare for the next step in the SDG [sustainable development goals] process: devolving the SDGs to the national level. It will …


The Influence Of Basin Morphometry On The Regional Coherence Of Patterns Of Diatom-Inferred Salinity In Lakes Of The Northern Great Plains (Usa), Courtney R. Wigdahl, Jasmine E. Saros, Sherilyn C. Fritz, Jeffery R. Stone, Daniel R. Engstrom Jan 2014

The Influence Of Basin Morphometry On The Regional Coherence Of Patterns Of Diatom-Inferred Salinity In Lakes Of The Northern Great Plains (Usa), Courtney R. Wigdahl, Jasmine E. Saros, Sherilyn C. Fritz, Jeffery R. Stone, Daniel R. Engstrom

Department of Earth and Atmospheric Sciences: Faculty Publications

Sedimentary diatom profiles from saline lakes are frequently used to reconstruct lakewater salinity as an indicator of drought. However, diatom-inferred salinity (DI-salinity) reconstructions from geographically proximal sites in the Great Plains (USA) have yielded disparate results. This study explores how physical changes in lake habitat resulting from drought may affect climate inferences from salinity reconstructions. Differences in relationships among drought, lake-level change, and diatom community structure over the last century were examined for three saline lakes in the northern Great Plains with dissimilar DI-salinity records. At each site, models were developed relating available planktic:benthic (P:B) habitat area to lake-level change, …


Hydrochemical Investigation Of A Transient Parafluvial Zone Under Drought Conditions, Platte River, Nebraska, Audrey R. Boerner Dec 2013

Hydrochemical Investigation Of A Transient Parafluvial Zone Under Drought Conditions, Platte River, Nebraska, Audrey R. Boerner

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

Shallow groundwater (0.5 m -1.2 m deep) beneath a vegetated and non-vegetated fluvial island was observed in the lower Platte River, Nebraska, USA during exceptional summer drought. Over the course of three months, sub-hourly measurements of hydraulic head, and weekly measurements of redox indicators, δ2H, δ18O, and dissolved gases were analyzed together with nitrogen and carbon species from an array of shallow piezometers in the river bed and islands. These data were compared with the same parameters collected from a 15 m-deep riparian borehole. Vertical hydraulic gradients in the island piezometers indicated the vertical component to …


Preliminary Groundwater Level Changes At Selected Sites In Nebraska Following The Drought Of 2012, Aaron R. Young, Mark E. Burbach, Leslie M. Howard Apr 2013

Preliminary Groundwater Level Changes At Selected Sites In Nebraska Following The Drought Of 2012, Aaron R. Young, Mark E. Burbach, Leslie M. Howard

Conservation and Survey Division

No abstract provided.


Drought Planning Research In The United States: An Overview And Outlook, Xinyu Fu, Zhenghong Tang, Jianjun Wu, Kevin Mcmillan Jan 2013

Drought Planning Research In The United States: An Overview And Outlook, Xinyu Fu, Zhenghong Tang, Jianjun Wu, Kevin Mcmillan

Community and Regional Planning Program: Faculty Scholarly and Creative Activity

Drought is widely known as an insidious hazard due to its complex and unique characteristics. Drought disasters have brought tremendous economic losses and significant social and environmental impacts to communities across the globe. To further understand the hazard drought poses and provide insights into planning for drought preparedness, this article conducts a thorough literature review of drought hazard and drought planning frameworks within the United States. Two main approaches and three major forms of drought planning are discussed and summarized. Based on this review, a preliminary overview of drought planning status in the United States is presented. This study provides …


Drought Triggers And Declarations: Science And Policy Considerations For Drought Risk Management, Linda Courtenay Botterill, Michael J. Hayes Jan 2012

Drought Triggers And Declarations: Science And Policy Considerations For Drought Risk Management, Linda Courtenay Botterill, Michael J. Hayes

Drought Mitigation Center: Faculty Publications

This paper explores the value of triggers and declarations in the management of drought, bringing together two disciplinary perspectives, those of the public policy scholar and the climate scientist. These two perspectives highlight the complexity of the development and use of triggers in drought risk management by drawing on the experience of the United States, which has the most sophisticated system of drought triggers in the world, and that of Australia that has the most developed and longest standing national drought policy based on principles of risk management. The paper explores the advantages and disadvantages of triggers in managing drought, …


Farmer Perceptions Of Sustainable Agriculture Practices And Drought Risk Reduction In Nebraska, Usa, Cody L. Knutson, Tonya Haigh, Michael J. Hayes, Melissa Widhalm, J. Nothwehr, M. Kleinschmidt, L. Graf Jan 2011

Farmer Perceptions Of Sustainable Agriculture Practices And Drought Risk Reduction In Nebraska, Usa, Cody L. Knutson, Tonya Haigh, Michael J. Hayes, Melissa Widhalm, J. Nothwehr, M. Kleinschmidt, L. Graf

Drought Mitigation Center: Faculty Publications

Social factors, such as farming methods, have an impact on farm vulnerability to drought, but have received little research or policy attention. Some researchers and advocates have argued that sustainable agriculture systems are less vulnerable to climate risk than conventional systems because sustainable agriculture requires producers to have skills promoting adaptability. In this paper, we investigate producers’ perceptions on the use of sustainable agriculture in reducing drought risk, and what they believe would help them better adapt to drought. We surveyed and interviewed farmer members of two sustainable agriculture organizations in Nebraska, USA, during a multi-year drought period from 1999 …


Effects Of Drought On Avian Community Structure, Thomas P. Albright, Anna M. Pidgeon, Chadwick D. Rittenhouse, Murray K. Clayton, Curtis H. Flather, Patrick D. Culbert, Brian D. Wardlows, Volker C. Radeloff Jan 2010

Effects Of Drought On Avian Community Structure, Thomas P. Albright, Anna M. Pidgeon, Chadwick D. Rittenhouse, Murray K. Clayton, Curtis H. Flather, Patrick D. Culbert, Brian D. Wardlows, Volker C. Radeloff

Drought Mitigation Center: Faculty Publications

Droughts are expected to become more frequent under global climate change. Avifauna depend on precipitation for hydration, cover, and food. While there are indications that avian communities respond negatively to drought, little is known about the response of birds with differing functional and behavioral traits, what time periods and indicators of drought are most relevant, or how response varies geographically at broad spatial scales. Our goals were thus to determine (1) how avian abundance and species richness are related to drought, (2) whether community variations are more related to vegetation vigor or precipitation deviations and at what time periods relationships …


A 2200-Year Record Of Hydrologic Variability From Foy Lake, Montana, Usa, Inferred From Diatom And Geochemical Data, Lora R. Stevens, Jeffery R. Stone, Josh Campbell, Sherilyn C. Fritz Mar 2006

A 2200-Year Record Of Hydrologic Variability From Foy Lake, Montana, Usa, Inferred From Diatom And Geochemical Data, Lora R. Stevens, Jeffery R. Stone, Josh Campbell, Sherilyn C. Fritz

Department of Earth and Atmospheric Sciences: Faculty Publications

A 2200-yr long, high-resolution (~5 yr) record of drought variability in northwest Montana is inferred from diatoms and δ18O values of bio-induced carbonate preserved in a varved lacustrine core from Foy Lake. A previously developed model of the diatom response to lake-level fluctuations is used to constrain estimates of paleolake levels derived from the diatom data. High-frequency (decadal) fluctuations in the de-trended δ18O record mirror variations in wet/dry cycles inferred from Banff tree-rings, demonstrating the sensitivity of the oxygen-isotope values to changes in regional moisture balance. Low frequency (multi-centennial) isotopic changes may be associated with shifts …


Late-Holocene Flooding And Drought In The Northern Great Plains, Usa, Reconstructed From Tree Rings, Lake Sediments And Ancient Shorelines, M. D. Shapley, W. C. Johnson, D. R. Engstrom, W. R. Osterkamp Jan 2005

Late-Holocene Flooding And Drought In The Northern Great Plains, Usa, Reconstructed From Tree Rings, Lake Sediments And Ancient Shorelines, M. D. Shapley, W. C. Johnson, D. R. Engstrom, W. R. Osterkamp

United States Geological Survey: Staff Publications

During the AD 1990s the Waubay Lakes complex in eastern South Dakota experienced historically unprecedented high water levels. Property damage from this flooding led to an examination of the occurrence of past pluvial episodes and their relation to climate. A lOOO-year hydroclimate reconstruction was developed from local bur oak (Quercus macrocarpa) tree-ring records and lake-sediment cores. Analysis of lake shoreline and drainage features provides late-Quaternary geomorphic context for this high-resolution record. Tree-ring width and shell geochemistry of the ostracode Candona rawsoni show marked coherence, indicating synchronous responses to moisture balance in vegetation and lake salinity; geomorphic evidence …


Drought Monitoring Using Data Mining Techniques: A Case Study For Nebraska, Usa, Tsegaye Tadesse, Donald A. Wilhite, Sherri K. Harms, Michael J. Hayes, Steve Goddard Jan 2004

Drought Monitoring Using Data Mining Techniques: A Case Study For Nebraska, Usa, Tsegaye Tadesse, Donald A. Wilhite, Sherri K. Harms, Michael J. Hayes, Steve Goddard

Drought Mitigation Center: Faculty Publications

Drought has an impact on many aspects of society. To help decision makers reduce the impacts of drought, it is important to improve our understanding of the characteristics and relationships of atmospheric and oceanic parameters that cause drought. In this study, the use of data mining techniques is introduced to find associations between drought and several oceanic and climatic indices that could help users in making knowledgeable decisions about drought responses before the drought actually occurs. Data mining techniques enable users to search for hidden patterns and find association rules for target data sets such as drought episodes. These techniques …


Late-Holocene Dune Activity Linked To Hydrological Drought, Nebraska Sand Hills, Usa, Joseph A. Mason, James B. Swinehart, Ronald J. Goble, David B. Loope Jan 2004

Late-Holocene Dune Activity Linked To Hydrological Drought, Nebraska Sand Hills, Usa, Joseph A. Mason, James B. Swinehart, Ronald J. Goble, David B. Loope

Conservation and Survey Division

No abstract provided.


Late-Holocene Climate And Ecosystem History From Chesapeake Bay Sediment Cores, Usa, Debra A. Willard, Thomas M. Cronin, Stacey Verardo Jan 2003

Late-Holocene Climate And Ecosystem History From Chesapeake Bay Sediment Cores, Usa, Debra A. Willard, Thomas M. Cronin, Stacey Verardo

United States Geological Survey: Staff Publications

Palaeoclimate records from late-Holocene sediments in Chesapeake Bay, the largest estuary in the USA, provide evidence that both decadal to centennial climate variability and European colonization had severe impacts on the watershed and estuary. Using pollen and dinoflagellate cysts as proxies for mid-Atlantic regional precipitation, estuarine salinity and dissolved oxygen (DO) during the last 2300 years, we identified four dry intervals, centred on ad 50 (P1/D1), ad 1000 (P2/D2), ad 1400 (P3) and ad 1600 (P4). Two centennial-scale events, P1/D1 and P2/D2, altered forest composition and led to increased salinity and DO levels in the estuary. Intervals P3 and P4 …


Hydrologic Variation In The Northern Great Plains During The Last Two Millennia, Sherilyn C. Fritz, Emi Ito, Zicheng Yu, Kathleen R. Laird, Daniel R. Engstrom Mar 2000

Hydrologic Variation In The Northern Great Plains During The Last Two Millennia, Sherilyn C. Fritz, Emi Ito, Zicheng Yu, Kathleen R. Laird, Daniel R. Engstrom

Department of Earth and Atmospheric Sciences: Faculty Publications

Reconstructions of lake-water salinity at decadal resolution for the last 2,000 years are compared among three lakes in North Dakota to infer regional patterns of drought. The intersite comparisons are used to distinguish local variation in climate or hydrology from regional patterns of change. At one lake, diatom-inferred salinity and lake-water Mg/Ca inferred from ostracode shell chemistry are coherent, both in terms of direction and magnitude of change, indicating that each is a robust technique for reconstructing lake-water chemistry. The data show that the last 2,000 years have been characterized by frequent shifts between high and low salinity, suggesting shifts …


A Diatom-Based Reconstruction Of Drought Intensity, Duration, And Frequency From Moon Lake, North Dakota: A Sub-Decadal Record Of The Last 2,300 Years, Kathleen R. Laird, Sherilyn C. Fritz, Brian F. Cumming Apr 1998

A Diatom-Based Reconstruction Of Drought Intensity, Duration, And Frequency From Moon Lake, North Dakota: A Sub-Decadal Record Of The Last 2,300 Years, Kathleen R. Laird, Sherilyn C. Fritz, Brian F. Cumming

Department of Earth and Atmospheric Sciences: Faculty Publications

Diatom assemblages preserved in sediment cores from closed-basin lakes can provide high-resolution records of past hydrologic and climatic conditions, including long-term patterns in the intensity, duration, and frequency of droughts. At Moon Lake, a closed-basin lake in eastern North Dakota, a comparison of diatom-inferred salinity and the precipitation-based Bhalme-Mooley Drought Index (BMDI) over the last 100 years was highly significant, suggesting that the diatom record contains a sensitive archive of past climatic conditions. A sub-decadal record of inferred salinity for the past 2300 years indicates that extreme droughts of greater intensity than those during the 1930s “Dust Bowl” were more …


Changes In Photosynthesis Rate In Pinus Sylvestris L. And Pinus Banksiana Lamb Seedlings Subjected To Drought Stress, George A. Riggs Jr. May 1985

Changes In Photosynthesis Rate In Pinus Sylvestris L. And Pinus Banksiana Lamb Seedlings Subjected To Drought Stress, George A. Riggs Jr.

School of Natural Resources: Dissertations, Theses, and Student Research

No abstract provided.


Drought, Its Effects And Measures Of Control In Nebraska, G. E. Condra Apr 1944

Drought, Its Effects And Measures Of Control In Nebraska, G. E. Condra

Conservation and Survey Division

No abstract provided.