An Introduction to VegDRI

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An Introduction to VegDRI Dr. Brian
Wardlow National Drought Mitigation Center
(NDMC) University of Nebraska-Lincoln Cheyenne,
WY June 21, 2007
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What is VegDRI?

• VegDRI is a new drought index that combines
• climate data
• satellite-based observations of vegetation
  conditions
• biophysical information (land cover type,
  soils)
• to produce a high spatial resolution
  (1-kilometer2) indicator
• of drought-related vegetation stress that is
  updated
• every 2 weeks throughout the growing season.

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What is VegDRI?
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VegDRI vs. U.S. Drought Monitor
Goal of VegDRI Map and monitor more localized
patterns of drought-related vegetation stress
than commonly used drought indicators such as the
U.S. Drought Monitor (USDM).
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VegDRI ConceptIntegration of Satellite,
Climate, and Biophysical Data
Satellite Data
VegDRI Map
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VegDRI ConceptIntegration of Satellite,
Climate, and Biophysical Data
Satellite Data

• Satellite-based observations are used to
  highlight areas
• with anomalous vegetation conditions.
• - Provides continuous spatial coverage
  of general vegetation conditions
• at high spatial resolution (1-km2)
  over large geographic areas.
• - Deficits (compared to average
  condition) might be caused by
• drought, flooding, late greennup,
  land cover conversion, etc.

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VegDRI ConceptIntegration of Satellite,
Climate, and Biophysical Data
Climate Data

• Coarser-resolution climate information provides
  evidence
• for the interpretation of the satellite
  data anomalies to
• identify vegetation impacted by drought.
• - Drought areas identified by below
  average vegetation conditions
• recorded in the satellite data and
  drier than normal conditions
• in the climate data.

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VegDRI ConceptIntegration of Satellite,
Climate, and Biophysical Data
Biophysical Data

• Biophysical data are incorporated into the
  VegDRI to
• account for the different
  climate-vegetation response
• relationships that can occur for different
• - land cover types
• - soil types
• - land use practices (irrigated
  cropland)
• - ecosystem types

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VegDRI Modeling Approach
Model Inputs
Avg Seasonal Greenness
1-km2 VegDRI Map
Blue climate input Green satellite-based
observation of vegetation Red biophysical
variable
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VegDRI Expansion Schedule for the U.S.
() Note All states will have a historical
record of VegDRI from 1989 to
present.
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VegDRI Website and Products
VegDRI products are available at the VegDRI page
(debuted in May 2007) within the Monitoring
section of the NDMC website.
http//drought2.unl.edu/vegdri/VegDRI_Main.htm
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1. VegDRI Quick-View Maps(multiple spatial
scales)
Regional-level
State-level
Sub-state level
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1. VegDRI Quick-View Maps (cont).(land cover
type)
Complete view
Rangeland view
Cropland view
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2. VegDRI Area Statistics ( area)(currently
available at state-level only)
Wyoming June 4, 2007
Entire state
Rangeland
Cropland
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3. Change Maps
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3. Change Maps

• 3 Types
• Prior period
• ex. - June 4, 2007 vs. May 21, 2007
• 2) Same period from the prior year
• or a specific year in past
• ( currently not available)
• ex. June 4, 2007 vs. June 4, 2006
• Historical average ( currently not available)
• ex. June 4, 2007 vs. average for June
  4 (1989 through 2006)

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4. Trendlines
Plots the average VegDRI values over the growing
season for a specific geographic area (e.g.,
county) and land cover type (e.g., cropland and
rangeland). Comparisons of VegDRI could be made
between specific years and/or the long-term
average condition.
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5. Animations
Goal Visualize spatial and temporal changes in
drought patterns across a specific year or
multiple years for a state or sub-state region.
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Additional VegDRI Product Activities

• Complete time series of VegDRI maps (1989
  present)

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Additional VegDRI Product Activities

• Complete time series of VegDRI map (1989
  present)
• Weekly VegDRI maps

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Additional VegDRI Product Activities

• Complete time series of VegDRI map (1989
  present)
• Weekly VegDRI maps
• Higher spatial resolution VegDRI (500- or
  250-meters)

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Additional VegDRI Product Activities

• Complete time series of VegDRI map (1989
  present)
• Weekly VegDRI maps
• Higher spatial resolution VegDRI (500- or
  250-meters)
• Evaluation of VegDRIs accuracy
• feedback from ag. producers and climate experts
• comparison to crop yield data and soil moisture
  observations
• comparison to other drought monitoring info.
  (U.S. Drought Monitor)

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Additional VegDRI Product Activities

• Complete time series of VegDRI map (1989
  present)
• Weekly VegDRI maps
• Higher spatial resolution VegDRI (500- or
  250-meters)
• Evaluation of VegDRIs accuracy
• feedback from ag. producers and climate experts
• comparison to crop yield data and soil moisture
  observations
• comparison to other drought monitoring info.
  (U.S. Drought Monitor)
• Research to enhance the current VegDRI model

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• Possible Uses of VegDRI Information
• by Ranchers
• Justify sub-county declarations for the
  release of CRP
• lands for emergency grazing for parts of
  counties that
• might be severely impacted by drought.

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• Possible Uses of VegDRI Information
• by Ranchers
• Justify sub-county declarations for the
  release of CRP
• lands for emergency grazing for parts of
  counties that
• might be severely impacted by drought.
• Gauge rangeland and haying conditions in other
  states to
• determine locations to move cattle for
  grazing and
• purchase hay and other feed

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• Possible Uses of VegDRI Information
• by Ranchers
• Justify sub-county declarations for the
  release of CRP
• lands for emergency grazing for parts of
  counties that
• might be severely impacted by drought.
• Gauge rangeland and haying conditions in other
  states to
• determine locations to move cattle for
  grazing and
• purchase hay and other feed
• Guide to assist new ranchers better manage
  their grazing
• lands and become better land stewards
  during drought
• events

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The Users Perspective of VegDRI
- Initial impressions? - Comments? -
Suggestions? - Questions?