Skip to main content

Person

George Z Xian

Research Physical Scientist

Earth Resources Observation and Science (EROS) Center

Email: xian@usgs.gov
Office Phone: 605-594-2599
Fax: 605-594-6567
ORCID: 0000-0001-5674-2204

Location
EROS - Mundt Federal Building
47914 252nd Street
Sioux Falls , SD 57198-9801
US

Supervisor: Birgit Peterson
thumbnail
The importance of monitoring shrublands to detect and understand changes through time is increasingly recognized as critical to management. This dataset focuses on ecological change observation over ten years of field observation at 134 plots within two sites that are located in Southwestern of Wyoming, USA from 2008-2018. At sites 1 and 3, 134 long-term field observation plots were measured annually from 2008 to 2018. General plot locations were selected in 2006 using segments and spectral clusters on QuickBird imagery to identify the best locations for representing the variability of the entire site (one QuickBird image). Ground measurements were conducted using ocular measurements with cover was estimated from...
thumbnail
The need to monitor change in sagebrush steppe is urgent due to the increasing impacts of climate change, shifting fire regimes, and management practices on ecosystem health. Remote sensing provides a cost-effective and reliable method for monitoring change through time and attributing changes to drivers. We report an automated method of mapping rangeland fractional component cover over a large portion of the Northern Great Basin, USA, from 1986 to 2016 using a dense Landsat imagery time series. 2012 was excluded from the time-series due to a lack of quality imagery. Our method improved upon the traditional change vector method by considering the legacy of change at each pixel. We evaluate cover trends stratified...
Tags: AZ, Arizona, Arizona Plateau, Black Hills, Blue Mountains, All tags...
thumbnail
We developed an approach to quantify Urban Heat Island (UHI) extent and intensity in 50 cities of CONUS and its surrounding area by using surface temperature from Landsat surface temperature product in a time series manner. Landsat land surface temperature from Landsat Analysis Ready Data (ARD) were used to quantify surface temperature changes from 1985 to 2020. The current study assessed UHI intensity and its variations associated with urban development in an annual basis. Two datasets, over the study period, show that the maximum surface temperature in the high intensity urban area significantly increased while no significant trend was found in surrounding non-urban areas. These released datasets were spatially...
Abstract (from http://onlinelibrary.wiley.com/doi/10.1002/eap.1389/full): Woody plant encroachment and overall declines in perennial vegetation in dryland regions can alter ecosystem properties and indicate land degradation, but the causes of these shifts remain controversial. Determining how changes in the abundance and distribution of grass and woody plants are influenced by conditions that regulate water availability at a regional scale provides a baseline to compare how management actions alter the composition of these vegetation types at a more local scale and can be used to predict future shifts under climate change. Using a remote-sensing-based approach, we assessed the balance between grasses and woody plants...
thumbnail
The need to monitor change in sagebrush steppe is urgent due to the increasing impacts of climate change, shifting fire regimes, and management practices on ecosystem health. Remote sensing provides a cost-effective and reliable method for monitoring change through time and attributing changes to drivers. We report an automated method of mapping rangeland fractional component cover over a large portion of the Northern Great Basin, USA, from 1986 to 2016 using a dense Landsat imagery time series. 2012 was excluded from the time-series due to a lack of quality imagery. Our method improved upon the traditional change vector method by considering the legacy of change at each pixel. We evaluate cover trends stratified...
Tags: AZ, Arizona, Arizona Plateau, Black Hills, Blue Mountains, All tags...
View more...
ScienceBase brings together the best information it can find about USGS researchers and offices to show connections to publications, projects, and data. We are still working to improve this process and information is by no means complete. If you don't see everything you know is associated with you, a colleague, or your office, please be patient while we work to connect the dots. Feel free to contact sciencebase@usgs.gov.