The first map indicates the total rainfall amount from 1st to 31th August. Data is extracted from FAO field reports and the RainFall Estimate (RFE) Satellite Imagery as produced by the NOAA/USGS/FEWS/USAID project. The RFE images are obtained by interpolating various parameters recorded on the ground and obtained through remote sensing measurements such as: rainfall, relative humidity, wind speed, elevation, cold cloud temperatures.
The map below shows the forecast yield of cereals (maize, millet, sorghum) for the Sahelian countries for the 2000 cropping season, as percent of the average yield in the period 1994-99. The map is obtained by applying to each country a yield function which relates, in statistical terms for the period 1982-99, the output parameters from the FAO crop specific water balance model to the crop yield. For 2000, the water balance model uses reported precipitation or estimated rainfall from satellite imagery up to 31th August and average rainfall from 1st September to the end of the crop cycle.
Data source: NOAA - Prepared by: FAO, SDRN, Agrometeorology Group