OPERATIONAL EARLY WARNING SYSTEM USING SPOT-VEGETATION AND TERRA-MODIS TO PREDICT DESERT LOCUST OUTBREAKS

The Desert Locust (Schistocerca gregaria) is an insect whose distribution area extends from North Africa through the Near East to Southwest Asia. During invasion periods, adults form swarms that can fly or be carried by wind over great distances. These swarms can threaten crops located thousands of kilometres from their places of origin. Supported by its member countries, FAO established the “Emergency Prevention System for Transboundary Animal and Plant Pests and Diseases ” (EMPRES programme – Desert Locust Component) to minimize the risk of emergencies developing as a result of Desert Locust plagues. EMPRES has created an operational early warning system involving surveying for Locusts in order to find Desert Locust outbreaks as early as possible and prevent them from developing into serious upsurges or plagues. The system includes the use of SPOT-VEGETATION images received on a ten-day basis at FAO through ARTEMIS. The S10 SPOT-VEGETATION NDVI product and single channels (RED-NIR-SWIR) are analysed at the Desert Locust Information Service, FAO HQ for conditions favourable for Desert Locust reproduction and development. The images and analyses are then provided to each of the twenty countries via a FTP site where the Locust Information Officers can have direct access. The analyses aim to identify two sorts of error: i) Commission error (when NDVI indicates that there is vegetation but there is no real vegetation on the ground) ii) Omission error (when NDVI indicates no presenc