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Full-Text Articles in Physical Sciences and Mathematics
Evaluating Optical Remote Sensing Methods For Estimating Leaf Area Index For Corn And Soybean, Rohit Nandan, Varaprasad Bandaru, Jiaying He, Craig Daughtry, Prasanna Gowda, Andrew E. Suyker
Evaluating Optical Remote Sensing Methods For Estimating Leaf Area Index For Corn And Soybean, Rohit Nandan, Varaprasad Bandaru, Jiaying He, Craig Daughtry, Prasanna Gowda, Andrew E. Suyker
School of Natural Resources: Faculty Publications
The leaf area index (LAI) is a key crop biophysical variable influencing many vegetation processes. Spatial LAI estimates are essential to develop and improve spatial modeling tools to monitor vegetation conditions at large regional scales. Numerous optical remote sensing methods have been explored to retrieve crop-specific LAI at a regional scale using satellite observations. However, a major challenge is selecting a method that performance well under various conditions without local scale calibration. As such, we assessed the performance of existing statistical and physical approaches, developed based on parametric, non-parametric and radiative transfer model (RTM)-look-up-table based inversion, using field observations from …
Monitoring Agroecosystem Productivity And Phenology At A National Scale: A Metric Assessment Framework, Dawn M. Browning, Eric S. Russell, Guillermo E. Ponce-Campos, Nicole Kaplan, Andrew D. Richardson, Bijan Seyednasrollah, Sheri Spiegal, Nicanor Saliendra, Joseph G. Alfieri, John Baker, Carl Bernacchi, Brandon T. Bestelmeyer, David Bosch, Elizabeth H. Boughton, Raoul K. Boughton, Pat Clark, Gerald Flerchinger, Nuria Gomez-Casanovas, Sarah Goslee, Nick M. Haddad, David Hoover, Abdullah Jaradat, Marguerite Mauritz, Gregory W. Mccarty, Gretchen R. Miller, John Sadler, Amartya Saha, Russell L. Scott, Andrew Suyker, Craig Tweedie, Jeffrey D. Wood, Xukai Zhang, Shawn D. Taylor
Monitoring Agroecosystem Productivity And Phenology At A National Scale: A Metric Assessment Framework, Dawn M. Browning, Eric S. Russell, Guillermo E. Ponce-Campos, Nicole Kaplan, Andrew D. Richardson, Bijan Seyednasrollah, Sheri Spiegal, Nicanor Saliendra, Joseph G. Alfieri, John Baker, Carl Bernacchi, Brandon T. Bestelmeyer, David Bosch, Elizabeth H. Boughton, Raoul K. Boughton, Pat Clark, Gerald Flerchinger, Nuria Gomez-Casanovas, Sarah Goslee, Nick M. Haddad, David Hoover, Abdullah Jaradat, Marguerite Mauritz, Gregory W. Mccarty, Gretchen R. Miller, John Sadler, Amartya Saha, Russell L. Scott, Andrew Suyker, Craig Tweedie, Jeffrey D. Wood, Xukai Zhang, Shawn D. Taylor
School of Natural Resources: Faculty Publications
Effective measurement of seasonal variations in the timing and amount of production is critical to managing spatially heterogeneous agroecosystems in a changing climate. Although numerous technologies for such measurements are available, their relationships to one another at a continental extent are unknown. Using data collected from across the Long-Term Agroecosystem Research (LTAR) network and other networks, we investigated correlations among key metrics representing primary production, phenology, and carbon fluxes in croplands, grazing lands, and crop-grazing integrated systems across the continental U.S. Metrics we examined included gross primary productivity (GPP) estimated from eddy covariance (EC) towers and modelled from the Landsat …
Monitoring Agroecosystem Productivity And Phenology At A National Scale: A Metric Assessment Framework, Dawn M. Browning, Eric S. Russell, Guillermo E. Ponce-Campos, Nicole Kaplan, Andrew D. Richardson, Bijan Seyednasrollah, Sheri Spiegal, Nicanor Saliendra, Joseph G. Alfieri, John Baker, Carl Bernacchi, Brandon T. Bestelmeyer, David Bosch, Elizabeth H. Boughton, Raoul K. Boughton, Pat Clark, Gerald Flerchinger, Nuria Gomez-Casanovas, Sarah Goslee, Nick M. Haddad, David Hoover, Abdullah Jaradat, Marguerite Mauritz, Gregory W. Mccarty, Gretchen R. Miller, John Sadler, Amartya Saha, Russell L. Scott, Andrew Suyker, Craig Tweedie, Jeffrey D. Wood, Xukai Zhang, Shawn D. Taylor
Monitoring Agroecosystem Productivity And Phenology At A National Scale: A Metric Assessment Framework, Dawn M. Browning, Eric S. Russell, Guillermo E. Ponce-Campos, Nicole Kaplan, Andrew D. Richardson, Bijan Seyednasrollah, Sheri Spiegal, Nicanor Saliendra, Joseph G. Alfieri, John Baker, Carl Bernacchi, Brandon T. Bestelmeyer, David Bosch, Elizabeth H. Boughton, Raoul K. Boughton, Pat Clark, Gerald Flerchinger, Nuria Gomez-Casanovas, Sarah Goslee, Nick M. Haddad, David Hoover, Abdullah Jaradat, Marguerite Mauritz, Gregory W. Mccarty, Gretchen R. Miller, John Sadler, Amartya Saha, Russell L. Scott, Andrew Suyker, Craig Tweedie, Jeffrey D. Wood, Xukai Zhang, Shawn D. Taylor
School of Natural Resources: Faculty Publications
Effective measurement of seasonal variations in the timing and amount of production is critical to managing spatially heterogeneous agroecosystems in a changing climate. Although numerous technologies for such measurements are available, their relationships to one another at a continental extent are unknown. Using data collected from across the Long-Term Agroecosystem Research (LTAR) network and other networks, we investigated correlations among key metrics representing primary production, phenology, and carbon fluxes in croplands, grazing lands, and crop-grazing integrated systems across the continental U.S. Metrics we examined included gross primary productivity (GPP) estimated from eddy covariance (EC) towers and modelled from the Landsat …
Improving Landsat Predictions Of Rangeland Fractional Cover With Multi-Task Learning And Uncertainty, B.W. Allred, B. Bestelmeyer, C.S. Boyd, C. Brown, K.W. Davies, M. Ellsworth, T. Erickson, S.D. Fuhlendorf, T.V. Griffiths, V. Jansen, M.O. Jones, J. Karl, A. Knight, J.D. Maestas, J.J. Maynard, S.E. Mccord, D.E. Naugle, H.D. Starns, D. Twidwell, D.R. Uden
Improving Landsat Predictions Of Rangeland Fractional Cover With Multi-Task Learning And Uncertainty, B.W. Allred, B. Bestelmeyer, C.S. Boyd, C. Brown, K.W. Davies, M. Ellsworth, T. Erickson, S.D. Fuhlendorf, T.V. Griffiths, V. Jansen, M.O. Jones, J. Karl, A. Knight, J.D. Maestas, J.J. Maynard, S.E. Mccord, D.E. Naugle, H.D. Starns, D. Twidwell, D.R. Uden
School of Natural Resources: Faculty Publications
No abstract provided.
Aquatic Habitat Changes Within The Channelized And Impounded Arkansas River, Arkansas, Usa, Jonathan J. Spurgeon, Mike Rhodes, J. Wesley Neal, Kristine O. Evans
Aquatic Habitat Changes Within The Channelized And Impounded Arkansas River, Arkansas, Usa, Jonathan J. Spurgeon, Mike Rhodes, J. Wesley Neal, Kristine O. Evans
School of Natural Resources: Faculty Publications
River-wide changes in morphologic character following channelization and impoundment alter the occurrence and distribution of surface water and available habitats for aquatic organisms. Quantifying patterns of creation, redistribution or disappearance of habitats at river-wide and decadal spatiotemporal scales can promote understanding regarding trajectories of different habitat types following alteration and prospects of direct habitat enhancement projects within altered alluvial rivers. Newly available remote-sensing tools and databases may improve detection of river-wide changes in habitat through time. We used a combination of remote-sensing data and generalized linear models to assess changes in surface water coverage from 1984 to 2015 among aquatic …
Global Production And Free Access To Landsat-Scale Evapotranspiration With Eeflux And Eemetric, Ayse Kilic, R G. Allen, Philip A. Blankenau, Peter Revelle, Doruk Ozturk, Justin L. Huntington
Global Production And Free Access To Landsat-Scale Evapotranspiration With Eeflux And Eemetric, Ayse Kilic, R G. Allen, Philip A. Blankenau, Peter Revelle, Doruk Ozturk, Justin L. Huntington
School of Natural Resources: Faculty Publications
EEFlux (Earth Engine Evapotranspiration Flux) is a version of the METRIC (mapping evapotranspiration at high resolution with internal calibration) application that operates on the Google Earth Engine (EE). EEFlux has a web-based interface and provides free public access to transform Landsat images into 30 m spatial evapotranspiration (ET) data for terrestrial land areas around the globe. EE holds the entire Landsat archive to power EEFlux along with NLDAS/CFSV2 gridded weather data for estimating reference ET. EEFlux is a part of the upcoming OpenET platform (https://openetdata.org/ ) that has leveraged nonprofit funding to provide ET information to all of the lower …
Assessing Responses Of Betula Papyrifera To Climate Variability In A Remnant Population Along The Niobrara River Valley In Nebraska U.S. Through Dendroecological And Remote Sensing Techniques, Evan Bumann, Tala Awada, Brian Wardlow, Michael Hayes, Jane A. Okalebo, C. Helzer, Anastasios Mazis, J. Hiller, Paolo Cherubini
Assessing Responses Of Betula Papyrifera To Climate Variability In A Remnant Population Along The Niobrara River Valley In Nebraska U.S. Through Dendroecological And Remote Sensing Techniques, Evan Bumann, Tala Awada, Brian Wardlow, Michael Hayes, Jane A. Okalebo, C. Helzer, Anastasios Mazis, J. Hiller, Paolo Cherubini
School of Natural Resources: Faculty Publications
Remnant populations of Betula papyrifera have persisted in the Great Plains after the Wisconsin Glaciation along the Niobrara River Valley, Nebraska. Population health has declined in recent years, and has been hypothesized to be due to climate change. We used dendrochronological techniques to assess the response of B. papyrifera to microclimate (1950-2014), and satellite imagery [Landsat 5 TM (1985-2011) and MODIS (2000-2014)] derived NDVI as a proxy for population health. Growing-season streamflow and precipitation were positively correlated with raw and standardized tree-ring widths and basal area increment increase. Increasing winter and spring temperatures were unfavorable for tree growth while increasing …
Field-Scale Mapping Of Evaporative Stress Indicators Of Crop Yield: An Application Over Mead, Ne, Usa, Yang Yang, Martha C. Anderson, Feng Gao, Brian D. Wardlow, Christopher R. Hain, Jason A. Otkin, Joseph Alfieri, Yun Yang, Liang Sun, Wayne Dulaney
Field-Scale Mapping Of Evaporative Stress Indicators Of Crop Yield: An Application Over Mead, Ne, Usa, Yang Yang, Martha C. Anderson, Feng Gao, Brian D. Wardlow, Christopher R. Hain, Jason A. Otkin, Joseph Alfieri, Yun Yang, Liang Sun, Wayne Dulaney
School of Natural Resources: Faculty Publications
The Evaporative Stress Index (ESI) quantifies temporal anomalies in a normalized evapotranspiration (ET) metric describing the ratio of actual-to-reference ET (fRET) as derived from satellite remote sensing. At regional scales (3–10 km pixel resolution), the ESI has demonstrated the capacity to capture developing crop stress and impacts on regional yield variability in water-limited agricultural regions. However, its performance in some regions where the vegetation cycle is intensively managed appears to be degraded due to spatial and temporal limitations in the standard ESI products. In this study, we investigated potential improvements to ESI by generating maps of ET, …
Assessing Responses Of Betula Papyrifera To Climate Variability In A Remnant Population Along The Niobrara River Valley In Nebraska, U.S.A., Through Dendroecological And Remote-Sensing Techniques, E. Bumann, T. Awada, B. Wardlow, M. Hayes, J. Okalebo, C. Helzer, A. Mazis, J. Hiller, P. Cherubini
Assessing Responses Of Betula Papyrifera To Climate Variability In A Remnant Population Along The Niobrara River Valley In Nebraska, U.S.A., Through Dendroecological And Remote-Sensing Techniques, E. Bumann, T. Awada, B. Wardlow, M. Hayes, J. Okalebo, C. Helzer, A. Mazis, J. Hiller, P. Cherubini
School of Natural Resources: Faculty Publications
No abstract provided.
Quantification And Mapping Of Surface Residue Cover For Maize And Soybean Fields In South Central Nebraska, Vivek Sharma, Suat Irmak, Ayse Kilic, Vasudha Sharma, John E. Gilley, George Meyer, Stevan Z. Knezevic, D. B. Marx
Quantification And Mapping Of Surface Residue Cover For Maize And Soybean Fields In South Central Nebraska, Vivek Sharma, Suat Irmak, Ayse Kilic, Vasudha Sharma, John E. Gilley, George Meyer, Stevan Z. Knezevic, D. B. Marx
School of Natural Resources: Faculty Publications
The area cultivated under conservation tillage practices such as no-till and minimal tillage has recently increased in Midwestern states, including Nebraska. This increase, consequently, resulted in changes in some of the impacts of cropping systems on soil, such as enhancing soil and water quality, improving soil structure and infiltration, increasing water use efficiency, and promoting carbon sequestration. However, there are no methods currently available to quantify the percent crop residue cover (CRC) and the area under conservation tillage for maize and soybean at large scales on a continuous basis. This research used Landsat-7 (ETM+) and Landsat-8 (OLI) satellite data to …
Eeflux: A Landsat-Based Evapotranspiration Mapping Tool On The Google Earth Engine, Richard Allen, Charles Morton, Baburao Kamble, Ayse Kilic, Justin Huntington, David Thau, Noel Gorelick, Tyler Erickson, Rebecca Moore, Ricardo Trezza, Ian C. Ratcliffe, Clarence Robison
Eeflux: A Landsat-Based Evapotranspiration Mapping Tool On The Google Earth Engine, Richard Allen, Charles Morton, Baburao Kamble, Ayse Kilic, Justin Huntington, David Thau, Noel Gorelick, Tyler Erickson, Rebecca Moore, Ricardo Trezza, Ian C. Ratcliffe, Clarence Robison
School of Natural Resources: Faculty Publications
“EEFlux” is an acronym for ‘Earth Engine Evapotranspiration Flux.’ EEFlux is based on the operational surface energy balance model “METRIC” (Mapping ET at high Resolution with Internalized Calibration), and is a Landsat-imagebased process. Landsat imagery supports the production of ET maps at resolutions of 30 m, which is the scale of many human-impacted and human-interest activities including agricultural fields, forest clearcuts and vegetation systems along streams. ET over extended time periods provides valuable information regarding impacts of water consumption on Earth resources and on humans. EEFlux uses North American Land Data Assimilation System hourly gridded weather data collection for energy …
Joint Leaf Chlorophyll Content And Leaf Area Index Retrieval From Landsat Data Using A Regularized Model Inversion System (Regflec), Rasmus Houborg, Matthew Mccabe, Alessandro Cescatti, Feng Gao, Mitchell Schull, Anatoly A. Gitelson
Joint Leaf Chlorophyll Content And Leaf Area Index Retrieval From Landsat Data Using A Regularized Model Inversion System (Regflec), Rasmus Houborg, Matthew Mccabe, Alessandro Cescatti, Feng Gao, Mitchell Schull, Anatoly A. Gitelson
School of Natural Resources: Faculty Publications
Leaf area index (LAI) and leaf chlorophyll content (Chll) represent key biophysical and biochemical controls on water, energy and carbon exchange processes in the terrestrial biosphere. In combination, LAI and Chll provide critical information on vegetation density, vitality and photosynthetic potentials.However, simultaneous retrieval of LAI and Chll fromspace observations is extremely challenging. Regularization strategies are required to increase the robustness and accuracy of retrieved properties and enable more reliable separation of soil, leaf and canopy parameters. To address these challenges, the REGularized canopy reFLECtance model (REGFLEC) inversion system was refined to incorporate enhanced techniques for exploiting ancillary LAI and temporal …
Post-Disaster Assessment Of Northeastern Coastal Region For The 2011 Sendai Earthquake And Tsunami, Ruopu Li, Shishi Liu, Qingfeng Guan, Yi Peng
Post-Disaster Assessment Of Northeastern Coastal Region For The 2011 Sendai Earthquake And Tsunami, Ruopu Li, Shishi Liu, Qingfeng Guan, Yi Peng
School of Natural Resources: Faculty Publications
The 2011 Sendai Earthquake has hit the north-east of Japan triggering a destructive tsunami that has caused extensive damage. A fast and effective post-disaster assessment is highly imperative for the recovery of this region. This study modeled the tsunami-affected areas of coastal Fukushima Prefecture using Landsat-7 ETM+ data and terrain analysis. The result shows that most of the coastal areas were significantly affected by the tsunami. The low-lying plains along the coast are particularly vulnerable to the tsunami.