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Satellite imagery in the GIEWS Workstation
Estimated Rainfall images:

They show the rainfall estimated by NOAA using images acquired by METEOSAT. They are used for comparisons between rainfall and water requirements of plants in cultivated areas.

Resolution: 5 Km
Time delivery: 10 days
Coverage: Africa continent
Other available products: the difference of the current Estimated Rainfall with the average value

Estimated Rainfall: September 2007 dekad 2
(For latest images, please visit the GIEWS Workstation)


Estimated Rainfall, difference with average: September 2007 dekad 2
(For latest images, please visit the GIEWS Workstation)


Standardised Precipitation Index images:

They are derived from the NOAA Estimated Rainfall images. The SPI is an index based on the probability of precipitation for any time scale (1 month, 2 month, 3 month, etc.). It can be computed for different time scales, can provide early warning of drought, and help assess drought severity. SPI values range from -2 < to >+2. Negative values indicate drought conditions.

Resolution: 5 Km
Time delivery: 10 days
Coverage: Africa continent

Standardized Precipitation Index (SPI): September 2007 dekad 2
(For latest images, please visit the GIEWS Workstation)




Temperature, Evapotranspiration (Penman-Monteith) and Snow images:

They show average value of temperature, evapotranspiration and of snow coverage, as calculated by the Joint Research Centre, using the ECMWF (European Centre for Medium-Range Weather Forecast) atmospherical model.

Resolution: 0.5 degree
Time delivery: 10 days
Coverage: all the world
Other available products: the maximum and the minimum temperature in 10 days.


Temperature: September 2007 dekad 2
(For latest images, please visit the GIEWS Workstation)



Evapotraspiration (Penman-Monteith): September 2007 dekad 2
(For latest images, please visit the GIEWS Workstation)
Vegetation Index images:

They show the value of the Normalized Difference Vegetation Index (NDVI) using images acquired by SPOT. The NDVI is a non-linear transformation of the visible (red) and near-infrared bands of satellite information. It is defined as the difference between the visible (red) and near-infrared (nir) bands, over their sum (NDVI = nir - red / nir + red). The NDVI is an alternative measure of vegetation amount and condition. It is associated with vegetation canopy characteristics such as biomass, leaf area index and percentage of vegetation cover. The NDVI values range from -1 to +1.

Resolution: 1 Km
Time delivery: 10 days
Coverage: all the world
Other available products: the difference of the current NDVI with: the previous 10 days; the previous year in the same 10 days; with the average value.


Vegetation Index: September 2007 dekad 2
(For latest images, please visit the GIEWS Workstation)



Vegetation Index, difference with average: September 2007 dekad 2
(For latest images, please visit the GIEWS Workstation)