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Faculty Publications

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Articles 241 - 270 of 371

Full-Text Articles in Geography

Comparing Remotely Sensed Pictometry® Web Based Slope Distance Estimates With In Situ Total Station And Tape Slope Distance Estimates, David Kulhavy, Daniel Unger, Yanli Zhang, Phillip Bedford, I-Kuai Hung Jan 2016

Comparing Remotely Sensed Pictometry® Web Based Slope Distance Estimates With In Situ Total Station And Tape Slope Distance Estimates, David Kulhavy, Daniel Unger, Yanli Zhang, Phillip Bedford, I-Kuai Hung

Faculty Publications

Slope distance was measured between the top of 30 light poles and their respective ground level coordinate identified within a central parking lot on the campus of Stephen F. Austin State University, Nacogdoches, Texas. Slope distance measured using Pictometry® hyperspatial 4-inch (10.2 centimeters) multispectral imagery within a web based interface was compared to in situ total station and tape measured slope distance. The range for mean slope distance for Pictometry®, total station, and tape measured slope distance was 0.05 meters. Mean slope distance was 15.36 meters, 15.37 meters, and 15.41 meters for Pictometry®, total station, …

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Integrating Faculty Led Service Learning Training To Quantify Height Of Natural Resources From A Spatial Science Perspective, Daniel Unger, David Kulhavy, Kai Busch-Peterson, I-Kuai Hung Jan 2016

Integrating Faculty Led Service Learning Training To Quantify Height Of Natural Resources From A Spatial Science Perspective, Daniel Unger, David Kulhavy, Kai Busch-Peterson, I-Kuai Hung

Faculty Publications

Arthur Temple College of Forestry and Agriculture (ATCOFA) faculty members were trained how to integrate service learning activities within senior level classes at Stephen F. Austin State University (SFASU) in Nacogdoches, Texas. The service learning training, taught under the acronym Mentored Undergraduate Scholarship (MUGS), involved meeting with fellow faculty members over the course of an academic year during the fall semester to first learn how to incorporate service learning activities in a senior level class followed by its incorporation into a class the following spring semester. The service learning model was applied to students in GIS 420, a senior level …

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Incorporating Applied Undergraduate Research In Senior To Graduate Level Remote Sensing Courses, Richard Henley, Daniel Unger, David Kulhavy, I-Kuai Hung Jan 2016

Incorporating Applied Undergraduate Research In Senior To Graduate Level Remote Sensing Courses, Richard Henley, Daniel Unger, David Kulhavy, I-Kuai Hung

Faculty Publications

An Arthur Temple College of Forestry and Agriculture (ATCOFA) senior spatial science undergraduate student engaged in a multi-course undergraduate research project to expand his expertise in remote sensing and assess the applied instruction methodology employed within ATCOFA. The project consisted of performing a change detection land-use/land-cover classification for Nacogdoches and Angelina counties in Texas using satellite imagery. The dates for the imagery were spaced approximately ten years apart and consisted of four different acquisitions between 1984 and 2013. The classification procedure followed and expanded upon a series of concrete theoretical remote sensing principles, transforming the four remotely sensed raster images …

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African Fire Cultures, Cattle Ranching, And Colonial Landscape Transformations In The Neo-Tropics, Andrew Sluyter, Chris S. Duvall Jan 2016

African Fire Cultures, Cattle Ranching, And Colonial Landscape Transformations In The Neo-Tropics, Andrew Sluyter, Chris S. Duvall

Faculty Publications

No abstract provided.

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Guide For “Los Isleños” Field Trip, Conference Of Latin Americanist Geographers, New Orleans, 2017, Andrew Sluyter Jan 2016

Guide For “Los Isleños” Field Trip, Conference Of Latin Americanist Geographers, New Orleans, 2017, Andrew Sluyter

Faculty Publications

No abstract provided.

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Program For The Conference Of Latin Americanist Geographers, New Orleans, January 3-5, 2017, Andrew Sluyter Jan 2016

Program For The Conference Of Latin Americanist Geographers, New Orleans, January 3-5, 2017, Andrew Sluyter

Faculty Publications

No abstract provided.

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Abstract Book: Papers And Posters, Conference Of Latin Americanist Geographers, New Orleans, January 3-5, 2017, Andrew Sluyter Jan 2016

Abstract Book: Papers And Posters, Conference Of Latin Americanist Geographers, New Orleans, January 3-5, 2017, Andrew Sluyter

Faculty Publications

No abstract provided.

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Cattle Colonialism: An Environmental History Of The Conquest Of California And Hawai'i, Andrew Sluyter Jan 2016

Cattle Colonialism: An Environmental History Of The Conquest Of California And Hawai'i, Andrew Sluyter

Faculty Publications

No abstract provided.

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Centering Animals In Latin American History, Andrew Sluyter Jan 2016

Centering Animals In Latin American History, Andrew Sluyter

Faculty Publications

No abstract provided.

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Rainforest Cowboys: The Rise Of Ranching And Cattle Culture In Western Amazonia By Jeffrey Hoelle (Review), Andrew Sluyter Jan 2016

Rainforest Cowboys: The Rise Of Ranching And Cattle Culture In Western Amazonia By Jeffrey Hoelle (Review), Andrew Sluyter

Faculty Publications

No abstract provided.

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Using Synthetic Tropical Cyclones To Characterize Extreme Hurricanes Affecting Charleston, South Carolina, Kelsey N. Ellis, Jill C. Trepanier, Robert E. Hodges Jan 2016

Using Synthetic Tropical Cyclones To Characterize Extreme Hurricanes Affecting Charleston, South Carolina, Kelsey N. Ellis, Jill C. Trepanier, Robert E. Hodges

Faculty Publications

The characteristics and conditions favoring extreme hurricanes remain largely unknown because of their small number in the observational record. Synthetic tracks are capable of providing a large, representative sample of these events, which provides an opportunity to further understanding of extreme characteristics as compared with those of more common tropical cyclones. The authors compare 300 synthetic extreme (100-yr event, ≥ 48.9 m s-1) and 300 common (5-yr event, ≤ 33.6 m s-1) tropical cyclones for Charleston, South Carolina, for differences in spatial, temporal, and other characteristics. Results suggest that extreme hurricanes have a more-defined spatial and temporal behavior, generally forming …

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Editorial, Thomas J. Lampoltshammer, Michael Leitner, Noella Edelmann Jan 2016

Editorial, Thomas J. Lampoltshammer, Michael Leitner, Noella Edelmann

Faculty Publications

No abstract provided.

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Mapping Rice Cropping Systems In Vietnam Using An Ndvi-Based Time-Series Similarity Measurement Based On Dtw Distance, Xudong Guan, Chong Huang, Gaohuan Liu, Xuelian Meng, Qingsheng Liu Jan 2016

Mapping Rice Cropping Systems In Vietnam Using An Ndvi-Based Time-Series Similarity Measurement Based On Dtw Distance, Xudong Guan, Chong Huang, Gaohuan Liu, Xuelian Meng, Qingsheng Liu

Faculty Publications

Normalized Difference Vegetation Index (NDVI) derived from Moderate Resolution Imaging Spectroradiometer (MODIS) time-series data has been widely used in the fields of crop and rice classification. The cloudy and rainy weather characteristics of the monsoon season greatly reduce the likelihood of obtaining high-quality optical remote sensing images. In addition, the diverse crop-planting system in Vietnam also hinders the comparison of NDVI among different crop stages. To address these problems, we apply a Dynamic TimeWarping (DTW) distance-based similarity measure approach and use the entire yearly NDVI time series to reduce the inaccuracy of classification using a single image. We first de-noise …

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Object-Based Crop Classification With Landsat-Modis Enhanced Time-Series Data, Qingting Li, Cuizhen Wang, Bing Zhang, Linlin Lu Dec 2015

Object-Based Crop Classification With Landsat-Modis Enhanced Time-Series Data, Qingting Li, Cuizhen Wang, Bing Zhang, Linlin Lu

Faculty Publications

Cropland mapping via remote sensing can provide crucial information for agri-ecological studies. Time series of remote sensing imagery is particularly useful for agricultural land classification. This study investigated the synergistic use of feature selection, Object-Based Image Analysis (OBIA) segmentation and decision tree classification for cropland mapping using a finer temporal-resolution Landsat-MODIS Enhanced time series in 2007. The enhanced time series extracted 26 layers of Normalized Difference Vegetation Index (NDVI) and five NDVI Time Series Indices (TSI) in a subset of agricultural land of Southwest Missouri. A feature selection procedure using the Stepwise Discriminant Analysis (SDA) was performed, and 10 optimal …

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Characterizing The Sediment Bed In Terms Of Resistance To Motion: Toward An Improved Model Of Saltation Thresholds For Aeolian Transport, Brandon L. Edwards, Steven L. Namikas Dec 2015

Characterizing The Sediment Bed In Terms Of Resistance To Motion: Toward An Improved Model Of Saltation Thresholds For Aeolian Transport, Brandon L. Edwards, Steven L. Namikas

Faculty Publications

Models of aeolian transport thresholds generate a wide range of predictions, and error in threshold modeling leads to uncertainty in predicting aeolian events. This paper proposes a new characterization of the representative grain size for use in prediction of transport thresholds. This characterization is based on the distribution of resistance to motion in the sediment bed. The traditional grain size distribution uses a mean diameter to represent the sediment bed. However, the distribution of inertial forces resisting motion is not linearly proportional to the distribution of grain diameters, so that an arithmetic mean does not adequately represent the distribution of …

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Modis-Derived Spatiotemporal Changes Of Major Lake Surface Areas In Arid Xinjiang, China, 2000–2014, Qingting Li, Linlin Lu, Cuizhen Wang, Yingkui Li, Yue Sui, Huadong Guo Oct 2015

Modis-Derived Spatiotemporal Changes Of Major Lake Surface Areas In Arid Xinjiang, China, 2000–2014, Qingting Li, Linlin Lu, Cuizhen Wang, Yingkui Li, Yue Sui, Huadong Guo

Faculty Publications

Inland water bodies, which are critical freshwater resources for arid and semi-arid areas, are very sensitive to climate change and human disturbance. In this paper, we derived a time series of major lake surface areas across Xinjiang Uygur Autonomous Region (XUAR), China, based on an eight-day MODIS time series in 500 m resolution from 2000 to 2014. A classification approach based on water index and dynamic threshold selection was first developed to accommodate varied spectral features of water pixels at different temporal steps. The overall classification accuracy for a MODIS-derived water body is 97% compared to a water body derived …

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Spatial Information Divergence: Using Global And Local Indices To Compare Geographical Masks Applied To Crime Data, Ourania Kounadi, Michael Leitner Oct 2015

Spatial Information Divergence: Using Global And Local Indices To Compare Geographical Masks Applied To Crime Data, Ourania Kounadi, Michael Leitner

Faculty Publications

Advances in Geographic Information Science (GISc) and the increasing availability of location data have facilitated the dissemination of crime data and the abundance of crime mapping websites. However, data holders acknowledge that when releasing sensitive crime data there is a risk of compromising the victims' privacy. Hence, protection methodologies are primarily applied to the data to ensure that individual privacy is not violated. This article addresses one group of location protection methodologies, namely geographical masks that are applicable for crime data representations. The purpose is to identify which mask is the most appropriate for crime incident visualizations. A global divergence …

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A Collection Of Sub-Daily Pressure And Temperature Observations For The Early Instrumental Period With A Focus On The “Year Without A Summer” 1816, Y. Brugnara, R. Auchmann, S. Brönnimann, R. J. Allan, I. Auer, M. Barriendos, H. Bergström, J. Bhend, R. Brázdil, G. P. Compo, R. C. Cornes, F. Dominguez-Castro, A. F.V. Van Engelen, J. Filipiak, J. Holopainen, S. Jourdain, M. Kunz, J. Luterbacher, M. Maugeri, L. Mercalli, A. Moberg, Cary J. Mock, G. Pichard, L. Åezníčková, G. Van Der Schrier, V. Slonosky, Z. Ustrnul, M. A. Valente, A. Wypych, X. Yin Aug 2015

A Collection Of Sub-Daily Pressure And Temperature Observations For The Early Instrumental Period With A Focus On The “Year Without A Summer” 1816, Y. Brugnara, R. Auchmann, S. Brönnimann, R. J. Allan, I. Auer, M. Barriendos, H. Bergström, J. Bhend, R. Brázdil, G. P. Compo, R. C. Cornes, F. Dominguez-Castro, A. F.V. Van Engelen, J. Filipiak, J. Holopainen, S. Jourdain, M. Kunz, J. Luterbacher, M. Maugeri, L. Mercalli, A. Moberg, Cary J. Mock, G. Pichard, L. Åezníčková, G. Van Der Schrier, V. Slonosky, Z. Ustrnul, M. A. Valente, A. Wypych, X. Yin

Faculty Publications

The eruption of Mount Tambora (Indonesia) in April 1815 is the largest documented volcanic eruption in history. It is associated with a large global cooling during the following year, felt particularly in parts of Europe and North America, where the year 1816 became known as the "year without a summer". This paper describes an effort made to collect surface meteorological observations from the early instrumental period, with a focus on the years of and immediately following the eruption (1815-1817). Although the collection aimed in particular at pressure observations, correspondent temperature observations were also recovered. Some of the series had already …

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Lithium In Drinking Water And Suicide Mortality: Interplay With Lithium Prescriptions, Marco Helbich, Michael Leitner, Nestor D. Kapusta Jul 2015

Lithium In Drinking Water And Suicide Mortality: Interplay With Lithium Prescriptions, Marco Helbich, Michael Leitner, Nestor D. Kapusta

Faculty Publications

Background: Little is known about the effects of lithium intake through drinking water on suicide. This intake originates either from natural rock and soil elution and/or accumulation of lithium-based pharmaceuticals in ground water. Aims: To examine the interplay between natural lithium in drinking water, prescribed lithium-based pharmaceuticals and suicide in Austria. Method: Spatial Bayesian regressions for males, females and pooled suicide mortality rates were estimated. Results: Although the expected inverse association between lithium levels in drinking water and suicide mortality was confirmed for males and for total suicide rates, the relationship for females was not significant. The models do not …

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The International Surface Pressure Databank Version 2, Thomas A. Cram, Gilbert P. Compo, Xungang Yin, Robert J. Allan, Chesley Mccoll, Russell S. Vose, Jeffrey S. Whitaker, Nobuki Matsui, Linden Ashcroft, Renate Auchmann, Pierre Bessemoulin, Theo Brandsma, Philip Brohan, Manola Brunet, Joseph Comeaux, Richard Crouthamel, Byron E. Gleason, Pavel Y. Groisman, Hans Hersbach, Philip D. Jones, Trausti Jónsson, Sylvie Jourdain, Gail Kelly, Kenneth R. Knapp, Andries Kruger, Hisayuki Kubota, Gianluca Lentini, Andrew Lorrey, Neal Lott, Sandra J. Lubker, Jürg Luterbacher, Gareth J. Marshall, Maurizio Maugeri, Cary J. Mock, Et. Al. Jul 2015

The International Surface Pressure Databank Version 2, Thomas A. Cram, Gilbert P. Compo, Xungang Yin, Robert J. Allan, Chesley Mccoll, Russell S. Vose, Jeffrey S. Whitaker, Nobuki Matsui, Linden Ashcroft, Renate Auchmann, Pierre Bessemoulin, Theo Brandsma, Philip Brohan, Manola Brunet, Joseph Comeaux, Richard Crouthamel, Byron E. Gleason, Pavel Y. Groisman, Hans Hersbach, Philip D. Jones, Trausti Jónsson, Sylvie Jourdain, Gail Kelly, Kenneth R. Knapp, Andries Kruger, Hisayuki Kubota, Gianluca Lentini, Andrew Lorrey, Neal Lott, Sandra J. Lubker, Jürg Luterbacher, Gareth J. Marshall, Maurizio Maugeri, Cary J. Mock, Et. Al.

Faculty Publications

The International Surface Pressure Databank (ISPD) is the world's largest collection of global surface and sea-level pressure observations. It was developed by extracting observations from established international archives, through international cooperation with data recovery facilitated by the Atmospheric Circulation Reconstructions over the Earth (ACRE) initiative, and directly by contributing universities, organizations, and countries. The dataset period is currently 1768–2012 and consists of three data components: observations from land stations, marine observing systems, and tropical cyclone best track pressure reports. Version 2 of the ISPD (ISPDv2) was created to be observational input for the Twentieth Century Reanalysis Project (20CR) and contains …

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Evaluation Of Three Modis-Derived Vegetation Index Time Series For Dryland Vegetation Dynamics Monitoring, Linlin Lu, Claudia Kuenzer, Cuizhen Wang, Huadong Guo, Qingting Li Jun 2015

Evaluation Of Three Modis-Derived Vegetation Index Time Series For Dryland Vegetation Dynamics Monitoring, Linlin Lu, Claudia Kuenzer, Cuizhen Wang, Huadong Guo, Qingting Li

Faculty Publications

Understanding the spatial and temporal dynamics of vegetation is essential in drylands. In this paper, we evaluated three vegetation indices, namely the Normalized Difference Vegetation Index (NDVI), the Soil-Adjusted Vegetation Index (SAVI) and the Enhanced Vegetation Index (EVI), derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) Surface-Reflectance Product in the Xinjiang Uygur Autonomous Region, China (XUAR), to assess index time series’ suitability for monitoring vegetation dynamics in a dryland environment. The mean annual VI and its variability were generated and analyzed from the three VI time series for the period 2001–2012 across XUAR. Two phenological metrics, start of the season …

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Improved Polsar Image Classification By The Use Of Multi-Feature Combination, Lei Deng, Ya-Nan Yan, Cuizhen Wang Apr 2015

Improved Polsar Image Classification By The Use Of Multi-Feature Combination, Lei Deng, Ya-Nan Yan, Cuizhen Wang

Faculty Publications

Polarimetric SAR (POLSAR) provides a rich set of information about objects on land surfaces. However, not all information works on land surface classification. This study proposes a new, integrated algorithm for optimal urban classification using POLSAR data. Both polarimetric decomposition and time-frequency (TF) decomposition were used to mine the hidden information of objects in POLSAR data, which was then applied in the C5.0 decision tree algorithm for optimal feature selection and classification. Using a NASA/JPL AIRSAR POLSAR scene as an example, the overall accuracy and kappa coefficient of the proposed method reached 91.17% and 0.90 in the L-band, much higher …

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Editorial, Michael Leitner, Marco Helbich Mar 2015

Editorial, Michael Leitner, Marco Helbich

Faculty Publications

No abstract provided.

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Hurricane Risk Variability Along The Gulf Of Mexico Coastline, Jill C. Trepanier, Kelsey N. Ellis, Clay S. Tucker Mar 2015

Hurricane Risk Variability Along The Gulf Of Mexico Coastline, Jill C. Trepanier, Kelsey N. Ellis, Clay S. Tucker

Faculty Publications

Hurricane risk characteristics are examined across the U. S. Gulf of Mexico coastline using a hexagonal tessellation. Using an extreme value model, parameters are collected representing the rate or λ (frequency), the scale or σ (range), and the shape or ζ (intensity) of the extreme wind distribution. These latent parameters and the 30-year return level are visualized across the grid. The greatest 30-year return levels are located toward the center of the Gulf of Mexico, and for inland locations, along the borders of Louisiana, Mississippi, and Alabama. Using a geographically weighted regression model, the relationship of these parameters to sea …

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Modis-Based Fractional Crop Mapping In The U.S. Midwest With Spatially Constrained Phenological Mixture Analysis, Cheng Zhong, Cuizhen Wang, Changshan Wu Jan 2015

Modis-Based Fractional Crop Mapping In The U.S. Midwest With Spatially Constrained Phenological Mixture Analysis, Cheng Zhong, Cuizhen Wang, Changshan Wu

Faculty Publications

Since the 2000s, bioenergy land use has been rapidly expanded in U.S. agricultural lands. Monitoring this change with limited acquisition of remote sensing imagery is difficult because of the similar spectral properties of crops. While phenology-assisted crop mapping is promising, relying on frequently observed images, the accuracies are often low, with mixed pixels in coarse-resolution imagery. In this paper, we used the eight-day, 500 m MODIS products (MOD09A1) to test the feasibility of crop unmixing in the U.S. Midwest, an important bioenergy land use region. With all MODIS images acquired in 2007, the 46-point Normalized Difference Vegetation Index (NDVI) time …

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Integrating Hands-On Undergraduate Research In An Applied Spatial Science Senior Level Capstone Course, David Kulhavy, Daniel R. Unger, I-Kuai Hung, David Douglass Jan 2015

Integrating Hands-On Undergraduate Research In An Applied Spatial Science Senior Level Capstone Course, David Kulhavy, Daniel R. Unger, I-Kuai Hung, David Douglass

Faculty Publications

A senior within a spatial science Ecological Planning capstone course designed an undergraduate research project to increase his spatial science expertise and to assess the hands-on instruction methodology employed within the Bachelor of Science in Spatial Science program at Stephen F Austin State University. The height of 30 building features estimated remotely with LiDAR data, within the Pictometry remotely sensed web-based interface, and in situ with a laser rangefinder were compared to actual building feature height measurements. A comparison of estimated height with actual height indicated that all three estimation techniques tested were unbiased estimators of height. An ANOVA, conducted …

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African Cowboys On The Argentine Pampas: Their Disappearance From The Historical Record, Andrew Sluyter Jan 2015

African Cowboys On The Argentine Pampas: Their Disappearance From The Historical Record, Andrew Sluyter

Faculty Publications

No abstract provided.

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Dreaming Of Dry Land: Environmental Transformation In Colonial Mexico City, Andrew Sluyter Jan 2015

Dreaming Of Dry Land: Environmental Transformation In Colonial Mexico City, Andrew Sluyter

Faculty Publications

No abstract provided.

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Trends And Spatial Variability In Dry Spells Across The South-Central United States, Jill C. Trepanier, Michael J. Roberts, Barry D. Keim Jan 2015

Trends And Spatial Variability In Dry Spells Across The South-Central United States, Jill C. Trepanier, Michael J. Roberts, Barry D. Keim

Faculty Publications

Annual average and maximum spells with no precipitation in the southern United States are analyzed. In this study, dry spells are defined as consecutive days with no measurable rainfall. The study area includes 70 weather stations in Texas, Oklahoma, Louisiana, Arkansas, Mississippi, and Tennessee. Interarrival times between daily precipitation records for each station provide the data for this analysis. All 70 stations were analyzed from 1950 to 2013. Six stations that each have data for more than 100 years were analyzed for the period from 1908 to 2013. Approximately 25% of stations in the region show significant negative trends through …

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Potential Of X-Band Images From High-Resolution Satellite Sar Sensors To Assess Growth And Yield In Paddy Rice, Yoshio Inoue, Eiji Sakaiya, Cuizhen Wang Jun 2014

Potential Of X-Band Images From High-Resolution Satellite Sar Sensors To Assess Growth And Yield In Paddy Rice, Yoshio Inoue, Eiji Sakaiya, Cuizhen Wang

Faculty Publications

The comprehensive relationship of backscattering coefficient (σ0) values from two current X-band SAR sensors (COSMO-SkyMed and TerraSAR-X) with canopy biophysical variables were investigated using the SAR images acquired at VV polarization and shallow incidence angles. The difference and consistency of the two sensors were also examined. The chrono-sequential change of σ0 in rice paddies during the transplanting season revealed that σ0 reached the value of nearby water surfaces a day before transplanting, and increased significantly just after transplanting event (3 dB). Despite a clear systematic shift (6.6 dB) between the two sensors, the differences in σ …

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