Locust monitoring using satellites
Currently available satellites cannot directly detect individual locusts or locust swarms. Some highly sophisticated satellites used by the military and forthcoming civilian satellites could potentially detect locust swarms but these images are not yet available. Current satellites can provide continuous estimates of rain-producing clouds and ecological conditions, such as vegetation development, which are important factors for monitoring Desert Locust habitats and forecasting locust development. The temporal, spectral and spatial characteristics of the sensor instruments onboard these satellites provide a wide range of sensing capabilities.
DLIS uses rainfall estimates derived from METEOSAT, mainly infrared and visible channels, to understand better the spatial and quantitative distribution of rainfall in the Desert Locust breeding areas. Although imagery are available every 15 minutes and estimates every three hours, DLIS uses daily 24-hour cumulative estimates as well as decadal estimates of rainfall processed by Columbia University's International Research Institute for Climate and Society (IRI). DLIS combines satellite-derived estimates with those that originate from meteorological models. Whenever possible, these are verified with ground data.
Until recently, DLIS relied on 1 km resolution SPOT-VGT imagery to monitor ecological conditions in the breeding areas of the Desert Locust. Although the sensor is specifically designed for vegetation monitoring, it has become clear that it is difficult to detect the sparse vegetation in the desert – vegetation that appears to be dry to the satellite yet sufficiently green for Desert Locust survival and breeding. Consequently, DLIS turned to higher resolution imagery, that of 250 metre resolution MODIS, consisting of 16-day cumulative images. Analysis of individual channels provides an even more accurate estimation of ecological conditions in Desert Locust habitats. Whenever possible, these are verified with survey results.
Current research and progress
FAO DLIS collaborates with a variety of universities and other partner institutes such as the Italian Institute of Biometeorology (IBIMET), the European Commission Joint Research Centre (JRC), Columbia University's International Research Institute for Climate and Society (IRI), NASA's World Wind Project, and the Catholic University of Louvain (Belgium) in improving the application of remote sensing imagery for Desert Locust monitoring and forecasting. SPOT-VGT and MODIS imagery is made available every 10 and 16 days respectively to locust-affected countries. These products are used to help guide national survey teams to potential areas of green vegetation where Desert Locust may be present.
A new collaboration is under way with the SMELLS project to develop a 10-day soil moisture map to help identify favourable areas for Desert Locust egg laying.