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Global Drought Monitoring: Agricultural Stress Index (ASI)

The Index is based on the integration of the Vegetation Health Index (VHI) in two dimensions that are critical in the assessment of a drought event in agriculture: temporal and spatial. The first step of the ASI calculation is a temporal averaging of the VHI, assessing the intensity and duration of dry periods occurring during the crop cycle at the pixel level; this calculation includes the use of crop coefficients, which introduces sensitivity of a crop to water stress during each phenological phase. The second step determines the spatial extent of drought events by calculating the percentage of pixels in arable areas with a VHI value below 35 percent (this value was identified as a critical threshold in assessing the extent of drought in previous research by Kogan, 1995). Each administrative area is classified according to the percentage of the affected area to facilitate the quick interpretation of results.

Important note: Map legend value= Pixel physical value * multiplier (0.5)

Data Resources (2)

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Additional Info

Field Value
Dataset topic category
  • Crop products and commodities
  • Drought
  • SDG13 Climate Action
  • English
Dataset reference date January 1, 2020
Temporal extent's start date January 1, 2000
Temporal extent's end date January 1, 2020
  • Global
Positional Accuracy There is no information about positional accuracy.
Attribute Accuracy There is no attribute accuracy known.
Logical Consistency There is no logical consistency known.
Completeness The data is completed.
Lineage Global Information and Early Warning System on Food and Agriculture (
Limitations on public access

No license given

Copyright Yes
Keywords vegetation drought
Date uploaded November 12, 2020, 19:23 (UTC)
Date modified November 16, 2020, 09:23 (UTC)