Temuulen "Teki" Sankey
Assistant Research Professor
ARD Building, Room 122
1298 S. Knoles Drive
Flagstaff, AZ 86011
- Remote sensing: multispectral satellite data and 3-dimensional
- Geospatial analysis, geoinformatics, geostatistics, GIS
- Unmanned aerial vehicle (UAV) image analysis and
- Data fusion: spectral data and 3-dimensional point cloud
- Ph.D, Land Resources and Environmental Sciences, Montana State University, 2006
- MS, Land Resources and Environmental Sciences, Montana State University, 2001
- BA, Foreign Language University, Ulaanbaatar, Mongolia, 1996
My research focuses on geospatial
data analysis and applications in coupled human-environment systems. I use
satellite-borne multispectral data and airborne hyperspectral and 3-dimensional
point cloud data in geospatial and environmental applications. The ecosystems I have studied include:
grassland-forest ecotones, aspen communities and pinyon-juniper woodlands of
the intermountain USA, sagebrush steppe in the northern Great Basin and
Columbia Plateau, USA, and grassland steppe and Siberian larch forests of
At a global scale, I study cropland
distribution and changes over time as they relate to global food security
concerns. As a part of the global cropland research, I advise a PhD student and
a post-doctorate research scientist at NAU-USGS. You can read more about this
project at: http://news.nau.edu/projects-cropland-map-of-the-world-to-be-most-detailed-ever/. In this study, I use continental scale Landsat and MODIS
time-series data leveraging NAU’s computing cluster Monsoon.
At a regional scale, I examine
climate change effects on southwestern desert plant communities in
collaboration with USGS and National Park Service scientists. This study also
uses Landsat time-series data in combination with field-based, long-term
vegetation monitoring data.
At a local scale, I currently have a
Bureau of Reclamation-funded project to evaluate snow water equivalence and
soil moisture response to restoration treatments in ponderosa pine forests in
northern Arizona. I advise a PhD student and mentor an undergraduate student in
this project. We use a combination of MODIS, Landsat, WorldView-2, and
UAV-based high resolution images to examine spatial and temporal variability in
snow distribution as impacted by restoration treatments. We expect the high
resolution UAV-based data and WorldView-2 images to provide a strong bridge
between point-based field measurements and moderate and coarse resolution
satellite data. The UAV-based snow-on and snow-off 3-dimensional lidar data can
provide high resolution estimates of snow accumulation and spatial patterns as
impacted by restoration treatments.
In many more local-scale studies, my
lab group is excited to use our newly-acquired UAV, which was funded by NAU
TRIF. The custom-engineered UAV has a unique capability to carry a large payload
including a hyperspectral sensor, which images the Earth in over 350 spectral
bands at 5 cm resolution, and a lidar scanner, which images the land surface
and vegetation in 3-dimensions. The lidar’s cm-resolution, 3-dimensional
mapping capability is valuable for a large range of science and engineering
applications, spanning from engineering grade mapping of built and natural
environments to detailed geologic mapping and inventory of forest biomass and
carbon. The hyperspectral imagery is particularly valuable for detailed
investigation related to soils, minerals, plants, and water.
Sankey Lab Group
You can read about people in my labhere.
EES529: Applied Remote Sensing
GSP529: Applied Remote Sensing
- Sankey, T., B. Dickson, S. Sesnie, O. Wang, and L.
Zachmann. 2014. WorldView-2 high resolution improves desert invasive plant
detection. Photogrammetric Engineering and Remote Sensing
- Sankey, T., R. Shreshtha, J. Sankey, and S.
Hardegree. 2013. Lidar-derived carbon estimates in woody encroachment. Journal of Geophysical Research 118:
S., N. Glenn, T. Sankey, and J.
McNamara. 2013. Influence of a dense, low-height shrub species on the accuracy
of a lidar-derived DEM. Photogrammetric
Engineering and Remote Sensing 79: 421-431
J., M. Germino, A. Hoover, and T.
Sankey. 2012. Fire effects on the spatial patterning of soil properties in
sagebrush steppe, USA: Meta-analysis. International
Journal of Wildland Fires doi:10.1071/WF11092
L., B. Wilcox, J. Belnap, S. Ravi, P. D’Odorico, D. Childers, W. Gwenzi, G.
Okin, J. Wainwright, K. Caylor, and T.
Sankey. 2012. Understanding the role of ecohydrological feedbacks in
ecosystem-state change in drylands. Ecohydrology
J., N. Glenn, T. Sankey, D.
Derryberry, and M. Germino. 2012. Remote
sensing of sagebrush canopy nitrogen.Remote Sensing of Environment 124: 217-223
J., Glenn, N., Sankey, T.,
Derryberry, D., Anderson, M., and R. Hruska. 2012. Spectroscopic detection of
nitrogen concentrations in sagebrush. Remote
Sensing Letters 3:285-294
- Sankey, T. 2011. Decadal-scale aspen change detection
using Landsat 5TM and lidar data. Applied
Vegetation Science 2012: 84-98
- Sankey, T. and N. Glenn. 2011. Landsat
5 TM and lidar fusion for sub-pixel juniper tree cover estimates. Photogrammetric Engineering and Remote
Sensing 77 (12):1241-1248
- Glenn, N.,
Spaete, L., Sankey, T., Derryberry, D.,
Hardegree, S., and J. Mitchell. 2011. Errors in LiDAR-derived shrub height and
crown area on sloped terrain. Journal of
Arid Environments 75 (4):377-382
J., Glenn, N., Sankey, T.,
Derryberry, D., Anderson, M., and R. Hruska. 2011. Small-footprint LiDAR
estimations of sagebrush canopy characteristics. Photogrammetric Engineering and Remote Sensing 77(5): 521-530
- Sankey, T.T., and P. Bond. 2011. LiDAR-based classifications of
sagebrush communities. Rangeland Ecology
and Management 64: 92-98.
- Sankey, T.T., Glenn, N., Ehinger,
S., Boehm, A., and S. Hardegree. 2010. Characterizing western juniper expansion
via a fusion of Landsat 5 Thematic Mapper and lidar data. Rangeland Ecology and Management 63: 514-523
L., Glenn, N.,
Derryberry, D., Sankey, T., and S.
Hardegree. 2010. Vegetation and slope effects on accuracy of a LiDAR-derived
DEM in the sagebrush steppe. Remote Sensing Letters 2 (4): 317-326
- Theau, J., Sankey, T., and K. Weber. 2010.
Multi-scale analysis of vegetation indices in a semi-arid environment. GIScience and Remote Sensing 42 (2):1-16
- Weber, K., Sankey, T., and J. Theau. 2010. Local-scale
validation of the surface observation gridding system dataset with in-situ
weather observation in a semi-arid environment. International Journal of Remote Sensing 31: 4411-4422
- Sankey, T., Sankey, J., Weber, K., and C. Montagne.
2009. Geospatial assessment of grazing regime shifts and socio-political
changes in a Mongolian rangeland. Rangeland
Ecology and Management 62: 522-530
- Sankey, T.T. 2009. Regional assessment of aspen
change and spatial variability at decadal time scales. Remote Sensing 1(4): 896-914
- Sankey, T., and M. Germino. 2008. Assessment of
juniper encroachment with the use of satellite imagery and geospatial data. Rangeland Ecology and Management 61:
- Sankey, T. 2008. Learning from spatial
variability: Aspen persistence in the Centennial Valley, Montana. Forest Ecology and Management 255:
- Sankey, T., Moffet, C., and K. Weber. 2008. Post-fire
recovery of sagebrush communities: Assessment using SPOT-5 and Very Large-Scale
Aerial Imagery. Rangeland Ecology and
Management 61: 598-604.
- Sankey, T. 2008. Spatial patterns of Douglas-fir
and aspen forest expansion. New Forests
- Sankey, T. 2007. Woody-herbaceous-livestock
species interaction. Annals of Arid Zone
- Sankey, T., Graumlich, L., Montagne, C., Lawrence,
R., and J. Nielsen. 2006. Twentieth century forest-grassland ecotone shift in
Montana under differing livestock grazing pressure. Forest Ecology and Management 234: 282-292
- Sankey, T., Graumlich, L., Montagne, C., Lawrence,
R., and J. Nielsen. 2006. Lower forest-grassland ecotones and 20th century
livestock herbivory effects in northern Mongolia. Forest Ecology and Management 233: 36-44
- Sankey, T, J Sankey, K Weber, and C Montagne. 2012. "Changes in Pastoral
Land Use and Their Effects on Rangeland Vegetation Indices." In Change in Democratic Mongolia: Social Relations,
Health, Mobile Pastoralism, and Mining, edited by J Dierkes, Leiden, The
- Sankey, T. 2012. "Woody–Herbaceous–Livestock
Species Interaction." In Ecotones between forest
and grassland, edited by R Myster, 89-114. New York: Springer.
- Sankey, T. 2008. “Effects
of scale”. In: Encyclopedia of GIS
- Sankey, T. 2008. “Spatial
statistics”. In: Encyclopedia of GIS
Papers, Presentations & Posters
- Sankey, T. 2014.Predicting snow water equivalence and soil moisture in restored
ponderosa pine forests using satellite data. Interstate Stream Commission.
Annual Meeting, April 4, Albuquerque, NM.
- Sankey, T., R. Shrestha, J. Sankey, S. Hardegree,
and E. Strand. 2013. Lidar-derived estimate and uncertainty of carbon sink in
successional phases of woody encroachment. 12th Biennial Conference of Science
and Management on the Colorado Plateau, Sept. 16-19, Northern Arizona
University, Flagstaff, AZ.
- Sankey, T., and S. Hardegree. 2011. Geospatial
assessment of decadal scale juniper encroachment into sagebrush steppe. Chapman
Conference, Sun Valley, ID
- Glenn, N., J. Mitchell, L. Spaete, T. Sankey, R. Shrestha, and S. Hardegree. 2011. Modeling
semi-arid low-height vegetation with airborne LiDAR. Paper presented at 34th International Symposium on Remote
Sensing of Environment. 10-15 April 2011. Sydney, Australia.
- Mitchell, J., N. Glenn, T.
Sankey, M. Anderson, and R. Hruska. 2011. Hyperspectral remote sensing of
sagebrush canopy nitrogen. 34th International Symposium on Remote Sensing of
Environment. April 2011. Sydney, Australia.
T., R. Shrestha, J. Sankey, and S.
Hardegree. 2011. Lidar-derived carbon estimates in encroaching juniper
woodlands. American Geophysical Union. 5-9 December 2011. San Francisco, CA.
- Spaete, L., J. Mitchell, N. Glenn, R. Shrestha, T. Sankey, J. Murgoitio, S. Gould, T.
Leedy, and S. Hardegree. 2011. Vegetation cover and volume estimates in
semi-arid rangelands using LiDAR and hyperspectral data. American Geophysical
Union. 5-9 December 2011. San Francisco, CA.
- Glenn, N., J. Mitchell, L. Spaete, T. Sankey, R. Shrestha, and S. Hardegree. 2010. Modeling low-height
vegetation with airborne LiDAR. American Geophysical Union. 13-17 December
2010. San Francisco, CA.
T., N. Glenn, R. Shrestha, and S.
Hardegree. 2010. Fine-scale characterization of juniper expansion via lidar data
and fusion with Landsat 5 TM. American Geophysical Union. 13-17 December 2010.
San Francisco, CA.
- Mitchell, J., N. Glenn, T.
Sankey, D. Derryberry, M. Anderson, and R. Hruska. 2010. Spectroscopic
detection of Nitrogen concentrations in sagebrush: Applications in
Hyperspectral Remote Sensing. Idaho Section of the Society of Rangeland
Management, Winter Meeting. 10-12 November 2012. Idaho Falls, ID.
- Mitchell, J., N. Glenn, T. Sankey, and D. Derryberry. 2009.
LiDAR canopy height measurements in a sagebrush steppe ecosystem. Silvilaser
Conference. October, 2010. College Station, Texas.
- Sankey, T., K. Weber, J. Sankey, and C. Montagne.
2008. Changes in pastoral use and their effects on rangeland productivity.
International Conference in Commemoration of the 35th Anniversary of Diplomatic
Relations Between Mongolia and Canada - Contemporary Mongolia “Transitions,
Development and Social Transformations” November 14-17, Vancouver, B.C.,