George Xian
Dr. George Xian is a research physical scientist with the U.S. Geological Survey, Earth Resources Observation and Science Center. He researches the national land cover data development, land cover change, and land cover change impacts on climate and ecosystems using remote sensing information.
George has specialized in using multi-type remote sensing data to characterize land change and change assessment across the United States. He has also used Landsat thermal information to study urban thermal landscape change by collaborating with other researchers from U.S. Global Change Research Program and universities. He also has participated in the development of U.S. Fifth National Climate Assessment.
Science and Products
Filter Total Items: 73
Conterminous United States land cover change patterns 2001–2016 from the 2016 National Land Cover Database
The 2016 National Land Cover Database (NLCD) product suite (available on www.mrlc.gov), includes Landsat-based, 30 m resolution products over the conterminous (CONUS) United States (U.S.) for land cover, urban imperviousness, and tree, shrub, herbaceous and bare ground fractional percentages. The release of NLCD 2016 provides important new information on land change patterns across CONUS from 2001
Authors
Collin G. Homer, Jon Dewitz, Suming Jin, George Z. Xian, Catherine Costello, Patrick Danielson, Leila Gass, Michelle Funk, James Wickham, Steven Stehman, Roger F. Auch, Kurt H. Riitters
Lessons learned implementing an operational continuous United States national land change monitoring capability: The Land Change Monitoring, Assessment, and Projection (LCMAP) approach
Growing demands for temporally specific information on land surface change are fueling a new generation of maps and statistics that can contribute to understanding geographic and temporal patterns of change across large regions, provide input into a wide range of environmental modeling studies, clarify the drivers of change, and provide more timely information for land managers. To meet these need
Authors
Jesslyn F. Brown, Heather J. Tollerud, Christopher Barber, Qiang Zhou, John L. Dwyer, James Vogelmann, Thomas Loveland, Curtis Woodcock, Stephen V. Stehman, Zhe Zhu, Bruce Pengra, Kelcy Smith, Josephine Horton, George Z. Xian, Roger F. Auch, Terry L. Sohl, Kristi Sayler, Alisa L. Gallant, Daniel Zelenak, Ryan R. Reker, Jennifer R. Rover
Quantifying western U.S. rangelands as fractional components with multi-resolution remote sensing and in situ data
Quantifying western U.S. rangelands as a series of fractional components with remote sensing provides a new way to understand these changing ecosystems. Nine rangeland ecosystem components, including percent shrub, sagebrush (Artemisia), big sagebrush, herbaceous, annual herbaceous, litter, and bare ground cover, along with sagebrush and shrub heights, were quantified at 30 m resolution. Extensive
Authors
Matthew Rigge, Collin Homer, Lauren Cleeves, Deb Meyer, Brett Bunde, Hua Shi, George Z. Xian, Matthew R Bobo
Overall methodology design for the United States National Land Cover Database 2016 products
The National Land Cover Database (NLCD) 2016 provides a suite of data products, including land cover and land cover change of the conterminous United States from 2001 to 2016, at two- to three-year intervals. The development of this product is part of an effort to meet the growing demand for longer temporal duration and more frequent, accurate, and consistent land cover and change information. To
Authors
Suming Jin, Collin Homer, Limin Yang, Patrick Danielson, Jon Dewitz, Congcong Li, Zhe Zhu, George Z. Xian, Danny Howard
Assessment of the impacts of image signal-to-noise ratios in impervious surface mapping
Medium spatial resolution satellite images are frequently used to characterize thematic land cover and a continuous field at both regional and global scales. However, high spatial resolution remote sensing data can provide details in landscape structures, especially in the urban environment. With upgrades to spatial resolution and spectral coverage for many satellite sensors, the impact of the sig
Authors
George Z. Xian, Hua Shi, Cody Anderson, Zhuoting Wu
Performances of WorldView-3, Sentinel-2, and Landsat-8 data in mapping impervious surface
Many efforts have been made to map developed impervious surface from remotely sensed information in the last two decades. The U.S. Geological Survey (USGS) developed the National Land Cover Database (NLCD) to provide consistent land cover and change products for the Nation since 2001. Percent impervious surface area (ISA), one of the products in NLCD as a continuous field and estimated with Landsa
Authors
George Z. Xian, Hua Shi, Jon Dewitz, Zhuoting Wu
Using remote sensing to quantify ecosystem site potential community structure and deviation in the Great Basin, United States
The semi-arid Great Basin region in the Northwest U.S. is impacted by a suite of change agents including fire, grazing, and climate variability to which native vegetation can have low resilience and resistance. Assessing ecosystem condition in relation to these change agents is difficult due to a lack of a consistent and objective Site Potential (SP) information of the conditions biophysically pos
Authors
Matthew B. Rigge, Collin G. Homer, Bruce K. Wylie, Yingxin Gu, Hua Shi, George Z. Xian, Debra K. Meyer, Brett Bunde
Analysis of different sensor performances in impervious surface mapping
The U.S. Geological Survey (USGS) has developed the National Land Cover Database (NLCD) to provide consistent land cover and land cover change products for the nation since 2001. As one of products in the NLCD, the percent impervious surface area (ISA), which was estimated with Landsat imagery, represents the fraction of human-made impervious area in a 30-m grid and has been used to quantify urban
Authors
George Z. Xian, Hua Shi, Jon Dewitz, Zhuoting Wu
A new generation of the United States National Land Cover Database: Requirements, research priorities, design, and implementation strategies
The U.S. Geological Survey (USGS), in partnership with several federal agencies, has developed and released four National Land Cover Database (NLCD) products over the past two decades: NLCD 1992, 2001, 2006, and 2011. These products provide spatially explicit and reliable information on the Nation’s land cover and land cover change. To continue the legacy of NLCD and further establish a long-term
Authors
Limin Yang, Suming Jin, Patrick Danielson, Collin Homer, Leila Gass, Stacie M Bender, Adam Case, Catherine Costello, Jon Dewitz, Joyce Fry, Michelle Funk, Brian J. Granneman, Greg C Liknes, Matthew B. Rigge, George Z. Xian
Accuracy assessment of NLCD 2011 impervious cover data for the Chesapeake Bay region, USA
The National Land Cover Database (NLCD) contains three eras (2001, 2006, 2011) of percentage urban impervious cover (%IC) at the native pixel size (30 m-x-30 m) of the Landsat Thematic Mapper satellite. These data are potentially valuable to environmental managers and stakeholders because of the utility of %IC as an indicator of watershed and aquatic condition, but lack an accuracy assessment bec
Authors
James Wickham, Nate Herold, Stephen V. Stehman, Collin Homer, George Z. Xian, Peter Claggett
Historical cover trends in a sagebrush steppe ecosystem from 1985 to 2013: Links with climate, disturbance, and management
Understanding the causes and consequences of component change in sagebrush steppe is crucial for evaluating ecosystem sustainability. The sagebrush (Artemisia spp.) steppe ecosystem of the northwest USA has been impacted by the invasion of exotic grasses, increasing fire return intervals, changing land management practices, and fragmentation, often lowering the overall resilience to change. We uti
Authors
Hua Shi, Matthew B. Rigge, Collin G. Homer, George Z. Xian, Debbie Meyer, Brett Bunde
Methods for converting continuous shrubland ecosystem component values to thematic National Land Cover Database classes
The National Land Cover Database (NLCD) provides thematic land cover and land cover change data at 30-meter spatial resolution for the United States. Although the NLCD is considered to be the leading thematic land cover/land use product and overall classification accuracy across the NLCD is high, performance and consistency in the vast shrub and grasslands of the Western United States is lower tha
Authors
Matthew B. Rigge, Leila Gass, Collin G. Homer, George Z. Xian
Science and Products
Filter Total Items: 73
Conterminous United States land cover change patterns 2001–2016 from the 2016 National Land Cover Database
The 2016 National Land Cover Database (NLCD) product suite (available on www.mrlc.gov), includes Landsat-based, 30 m resolution products over the conterminous (CONUS) United States (U.S.) for land cover, urban imperviousness, and tree, shrub, herbaceous and bare ground fractional percentages. The release of NLCD 2016 provides important new information on land change patterns across CONUS from 2001
Authors
Collin G. Homer, Jon Dewitz, Suming Jin, George Z. Xian, Catherine Costello, Patrick Danielson, Leila Gass, Michelle Funk, James Wickham, Steven Stehman, Roger F. Auch, Kurt H. Riitters
Lessons learned implementing an operational continuous United States national land change monitoring capability: The Land Change Monitoring, Assessment, and Projection (LCMAP) approach
Growing demands for temporally specific information on land surface change are fueling a new generation of maps and statistics that can contribute to understanding geographic and temporal patterns of change across large regions, provide input into a wide range of environmental modeling studies, clarify the drivers of change, and provide more timely information for land managers. To meet these need
Authors
Jesslyn F. Brown, Heather J. Tollerud, Christopher Barber, Qiang Zhou, John L. Dwyer, James Vogelmann, Thomas Loveland, Curtis Woodcock, Stephen V. Stehman, Zhe Zhu, Bruce Pengra, Kelcy Smith, Josephine Horton, George Z. Xian, Roger F. Auch, Terry L. Sohl, Kristi Sayler, Alisa L. Gallant, Daniel Zelenak, Ryan R. Reker, Jennifer R. Rover
Quantifying western U.S. rangelands as fractional components with multi-resolution remote sensing and in situ data
Quantifying western U.S. rangelands as a series of fractional components with remote sensing provides a new way to understand these changing ecosystems. Nine rangeland ecosystem components, including percent shrub, sagebrush (Artemisia), big sagebrush, herbaceous, annual herbaceous, litter, and bare ground cover, along with sagebrush and shrub heights, were quantified at 30 m resolution. Extensive
Authors
Matthew Rigge, Collin Homer, Lauren Cleeves, Deb Meyer, Brett Bunde, Hua Shi, George Z. Xian, Matthew R Bobo
Overall methodology design for the United States National Land Cover Database 2016 products
The National Land Cover Database (NLCD) 2016 provides a suite of data products, including land cover and land cover change of the conterminous United States from 2001 to 2016, at two- to three-year intervals. The development of this product is part of an effort to meet the growing demand for longer temporal duration and more frequent, accurate, and consistent land cover and change information. To
Authors
Suming Jin, Collin Homer, Limin Yang, Patrick Danielson, Jon Dewitz, Congcong Li, Zhe Zhu, George Z. Xian, Danny Howard
Assessment of the impacts of image signal-to-noise ratios in impervious surface mapping
Medium spatial resolution satellite images are frequently used to characterize thematic land cover and a continuous field at both regional and global scales. However, high spatial resolution remote sensing data can provide details in landscape structures, especially in the urban environment. With upgrades to spatial resolution and spectral coverage for many satellite sensors, the impact of the sig
Authors
George Z. Xian, Hua Shi, Cody Anderson, Zhuoting Wu
Performances of WorldView-3, Sentinel-2, and Landsat-8 data in mapping impervious surface
Many efforts have been made to map developed impervious surface from remotely sensed information in the last two decades. The U.S. Geological Survey (USGS) developed the National Land Cover Database (NLCD) to provide consistent land cover and change products for the Nation since 2001. Percent impervious surface area (ISA), one of the products in NLCD as a continuous field and estimated with Landsa
Authors
George Z. Xian, Hua Shi, Jon Dewitz, Zhuoting Wu
Using remote sensing to quantify ecosystem site potential community structure and deviation in the Great Basin, United States
The semi-arid Great Basin region in the Northwest U.S. is impacted by a suite of change agents including fire, grazing, and climate variability to which native vegetation can have low resilience and resistance. Assessing ecosystem condition in relation to these change agents is difficult due to a lack of a consistent and objective Site Potential (SP) information of the conditions biophysically pos
Authors
Matthew B. Rigge, Collin G. Homer, Bruce K. Wylie, Yingxin Gu, Hua Shi, George Z. Xian, Debra K. Meyer, Brett Bunde
Analysis of different sensor performances in impervious surface mapping
The U.S. Geological Survey (USGS) has developed the National Land Cover Database (NLCD) to provide consistent land cover and land cover change products for the nation since 2001. As one of products in the NLCD, the percent impervious surface area (ISA), which was estimated with Landsat imagery, represents the fraction of human-made impervious area in a 30-m grid and has been used to quantify urban
Authors
George Z. Xian, Hua Shi, Jon Dewitz, Zhuoting Wu
A new generation of the United States National Land Cover Database: Requirements, research priorities, design, and implementation strategies
The U.S. Geological Survey (USGS), in partnership with several federal agencies, has developed and released four National Land Cover Database (NLCD) products over the past two decades: NLCD 1992, 2001, 2006, and 2011. These products provide spatially explicit and reliable information on the Nation’s land cover and land cover change. To continue the legacy of NLCD and further establish a long-term
Authors
Limin Yang, Suming Jin, Patrick Danielson, Collin Homer, Leila Gass, Stacie M Bender, Adam Case, Catherine Costello, Jon Dewitz, Joyce Fry, Michelle Funk, Brian J. Granneman, Greg C Liknes, Matthew B. Rigge, George Z. Xian
Accuracy assessment of NLCD 2011 impervious cover data for the Chesapeake Bay region, USA
The National Land Cover Database (NLCD) contains three eras (2001, 2006, 2011) of percentage urban impervious cover (%IC) at the native pixel size (30 m-x-30 m) of the Landsat Thematic Mapper satellite. These data are potentially valuable to environmental managers and stakeholders because of the utility of %IC as an indicator of watershed and aquatic condition, but lack an accuracy assessment bec
Authors
James Wickham, Nate Herold, Stephen V. Stehman, Collin Homer, George Z. Xian, Peter Claggett
Historical cover trends in a sagebrush steppe ecosystem from 1985 to 2013: Links with climate, disturbance, and management
Understanding the causes and consequences of component change in sagebrush steppe is crucial for evaluating ecosystem sustainability. The sagebrush (Artemisia spp.) steppe ecosystem of the northwest USA has been impacted by the invasion of exotic grasses, increasing fire return intervals, changing land management practices, and fragmentation, often lowering the overall resilience to change. We uti
Authors
Hua Shi, Matthew B. Rigge, Collin G. Homer, George Z. Xian, Debbie Meyer, Brett Bunde
Methods for converting continuous shrubland ecosystem component values to thematic National Land Cover Database classes
The National Land Cover Database (NLCD) provides thematic land cover and land cover change data at 30-meter spatial resolution for the United States. Although the NLCD is considered to be the leading thematic land cover/land use product and overall classification accuracy across the NLCD is high, performance and consistency in the vast shrub and grasslands of the Western United States is lower tha
Authors
Matthew B. Rigge, Leila Gass, Collin G. Homer, George Z. Xian