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Agricultural drought monitoring and early warning systems


Over the past 40 years, drought has affected more people in the world than any other natural hazard. Between 2006 and 2016, agriculture suffered about 83% of all damages and losses caused by drought globally. In developing countries, drought losses account to about 60-80% of national crop production. For smallholder farmers and pastoralists around the world, drought carries a constant risk.

Drought is also difficult to quantify and assess. Drought is a slow-developing hazard that may subside and again intensify over several months. Its impacts are one of the most complex natural hazards to predict and mitigate. Recent projections show that drought events are expected to increase in frequency and intensity due to climate change. Climate variability, including more frequent and intense extreme weather is increasingly exposing vulnerable populations, particularly in countries where compounded shocks are already a reality.

In the 90’s, FAO developed a methodology to evaluate the water availability to satisfy crop requirements based on the information provided by meteorological stations. Since 2014, FAO employs satellite information to generate agricultural drought assessments every 10-days at 1 km resolution. This approach takes into consideration the crop specific requirements of water during each phenological phase. Flowering and grain filling crop phases are recognized to be the more sensitive phases to water stress on cereals crops.

FAO’s Agricultural Stress Index System (ASIS) provides near real-time global, regional and country level data which supports decision makers with timely information crucial for preparing for and minimizing the impacts of drought on agriculture, the early warning-early action approach (EWEA).

ASIS is based on satellite imagery from the Advanced Very High Resolution
Radiometer (AVHRR) sensors on board of the National Oceanic and Atmospheric
Administration (NOAA) and Meteorological Operation Satellite (METOP). The severity of a
drought event (intensity, duration and spatial extent) is evaluated using the Vegetation Health Index (VHI)
derived from the Normalized Difference Vegetation Index (NDVI).


4 vital A’s of ASIS’ digital applications

Raw Earth Observation (EO) data used are in public domain. FAO owns full intellectual property of Global ASIS since July 2014.
Global coverage updated every 10 days, including 196 countries since 1984. User manual and training materials are available in various formats.
Designed for non EO-experts. Ready to be applied to other drought and climate related social and economic analyses.
IT operation cost at FAO HQs is low. FAO provides data support and free software

ASIS explained: