Remote Sensing Analyses to Detect Effects of Community ... · Community-based Rangeland Ecosystem...
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Remote Sensing Analyses to Detect Effects of
Community-based Rangeland Ecosystem
Management on Rangeland Vegetation
Jay Angerer
Texas A&M University
MOR2 Annual Meeting
June 15-16, 2012
Research Questions
During the last 30 years, has change occurred in vegetation characteristics such as green up, peak biomass and vegetation condition across Mongolia that can be detected with remote sensing?
Are there differences in vegetation response (using remote sensing data as a proxy) in soums managed by CBREM versus those that are not?
Can we detect changes in rainfall variability that could influence the status of grazinglands as equilibrium vs. non-equilibrium systems?
Historical Time Series
Analysis Time series analysis to examine
trends in satellite greenness (NDVI) for historical record (nationwide)
Patterns of green-up and senescence
Patterns in integrated NDVI (proxy for biomass accumulation)
Trends in vegetation condition index
TIMESAT Software TIMESAT software will be used for the developing the
time series data Calculates yearly beginning of season, end of season, amplitude, integrated
NDVI values
Available from: http://www.nateko.lu.se/TIMESAT/timesat.asp?cat=0
Green-up End of
Season
Integrated
NDVI
Data Sources
Advanced Very High Resolution Radiometer (AVHRR) – Normalized Difference Vegetation Index (NDVI) data Data processed by NASA-Global Inventory Modeling and
Mapping Studies
1981 to 2010
8 km resolution
Widely used
Available at http://www.glcf.umd.edu/data/gimms/
Paired Soum Analysis
Time series analysis for paired soums
Do differences exist in green-up, end of season, integrated NDVI, and vegetation condition for paired CBREM and non-CBREM soums?
Pre and Post CBREM analysis
What is the role of rainfall in this difference/pattern?
Vegetation Condition Index
Trends Vegetation Condition Index is calculated
by scaling NDVI for period of interest to
the historical minimum and maximum
(Current NDVI – minNDVI) / (maxNDVI – minNDVI) * 100
Values less than 30 are considered drought
Examine spatial extent and occurrence/intensity of
drought for the time series
Data Sources
Moderate Resolution Imaging Spectroradiometer (MODIS) NDVI data Expedited MODIS (eMODIS) - New product available from
USGS
2000 to present
Resolution of 250m
Available for Asia region
Download from: http://dds.cr.usgs.gov/emodis/CentralAsia/
AVHRR NDVI Pre and Post CBREM Analysis for each study soum
1981 to 1998 as Pre CBREM
1999 to Present as Post-CBREM
Data Sources
Unified Precipitation Dataset Product available from NOAA that uses optimal
interpolation
0.50 degree resolution (~55 km)
Daily Product, 1979 to present
Available from: ftp://ftp.cpc.ncep.noaa.gov/precip/CPC_UNI_PRCP/GAUGE_GLB/
Global Telecommunications System (GTS) Station Data Daily climate data for reporting World Meteorological
Organization (WMO) stations
Includes about 26 stations in Mongolia
Archived by Texas A&M
Rainfall Coefficient of
Variability (CV) Mapping Calculate Rainfall CV from CPC Unified
Precipitation data
Map the CV to identify potential equilibrium/non-
equilibrium zones
Examine in relation to paired soums
Rainfall CV Mapping
von Wehrden, H., J. Hanspach, P. Kaczensky, J. Fischer and K. Wesche. 2012.
A global assessment of the non-equilibrium concept in rangelands.
Ecological Applications, 22(2):393-399
Texas A&M splining of WMO
Dataset
Current Status
Processing AVHRR data using TIMESAT
software
eModis data has been processed, clipped,
and staged for TIMESAT analysis
CV analysis being conducted on Unified
Precipitation dataset
Questions or Comments?