Monitoring & Early Warning Food Assessment by Satellite Technology [FAST]

May 2005 overview

Southern Portugal and almost whole Spain suffer from lack of precipitation. In southern Africa crop growth is below average due to drought for the northern countries  The crop yields for Zimbabwe and Botswana are expected to be between 6 and 11% below average. In contrast the crop forecast for Lesotho, Swaziland and South Africa is good. In western Africa the main crop season started a little below average.


The precipitation of March in eastern Botswana and western Zimbabwe brought some relief, but it was too near to the end of the growing season to be of significant benefit for the crop growth. Further rainfall was absent. As the end of the growing season is near, the end of season crop yield estimates in the table below will not be subject to significant changes. As expected two months ago, South Africa, Lesotho and Swaziland are doing well, for the more northerly situated crop regions this year is not favorable. Remarkable is the situation in Zambia; though in the table presented by one figure, one should note that this is the sum of very low crop forecast in the South and a very good forecast in the North.


Left: Difference of the relative evapotranspiration with the five year average over the period September-May. Red = lower values, green = higher values.
Middle: Precipitation during September-May scaled from 0 (dark red) to 750 mm and over (blue).
Right: Maize end of season forecast relative to the 5 year average; scaled from 0 (red) to 100% (blue).


yield % (*)

yield % (*)

Angola 3 4
Botswana -4 -9
Lesotho 42 14
Malawi 2 -3
Mozambique 3 -1
Namibia 0 0
South Africa 42
Swaziland 14 9
Zambia -3 -5
Zimbabwe -6 -12

(*)End of season crop yield estimate for the 2004-2005 season expressed as % difference relative to the previous five year average. (-) not significant / out of season.

yield % (*)
Benin  -7
Ghana -2
Ivory Coast -4
Togo -7

(*) End of season crop yield estimate for 2004 expressed as % difference relative to the previous five year average. (-) not significant / out of season.


Drought remains in the southern part of the Iberian peninsula, the Balearic Islands, Sardinia, southern Italy and the eastern Ukraine. The southern Spanish and Portuguese forests are becoming susceptible to forest fire, although they are only at the verge of the dry season.

Precipitation during April scaled from 0 (red) to 50mm and over (blue).


Heavy rains fell in the Horn of Africa, northern Zaire, Central Africa, Uganda, Tanzania and Yemen as displayed below. According to Reliefweb this resulted in severe flooding in Ethiopia, Somalia and Kenya.


Left: Evapotranspiration in May relative to the 5 year average , scaled from -20% (red)-20% (blue).
Right: Rainfall during May scaled from 0 (red) to 150 mm or over (blue).

As is indicated by the table below the crop development at the beginning of the season is not very good, and is quite variable. However if we take the recent rainfall into account (image to the right), we can foresee some improvement. For instance Somalia and Sudan have a bad start of the season, but recent rainfall is likely to have improved the situation. These rains are setting the start of the Meher growing season in Ethiopia. In Kenya the crop development is good in the east (mainly Maize) but even more favorable in the west (Sorghum, Cassava, Barley).

yield % (*)
yield % (*)
Burundi (sec.) -4 -3
Congo Dem. (sec.) -3
Ethiopia 1 5
Kenya 5 9
Rwanda 0 -3
Somalia -10 -3
Sudan -15 -6
Tanzania (sec.) -3 -3
Uganda -3 2

(*) End of season crop yield estimate for 2004 expressed as % difference relative to the previous five year average. (-) not significant / out of season.

Although the absolute evapotranspiration is low in the Sahara, the relative evapotranspiration is exceptionally high. After last year Locust plagues this may be the onset for yet another year of this pest. As countries still suffer from last season’s pest (FEWS), the situation may become serious.


Left: Relative evapotranspiration during May 2005, scaled between zero (black), and 100 % or above (blue); right: relative to the 5 year average scaled between -20% (red), and 20% or above (blue).

At the start of the growing season, conditions are a little below average. However the season is just starting for the countries entered in the table, therefore these figures are only indicative in this stage.


The image below shows the actual evapotranspiration during March 2005 for our central Asia service.

Actual evapotranspiration during February 2005 scaled from red (low) to blue (high values).


LEAFLET on drought and crop yield monitoring

Click here for a printable version 


The Energy Balance Monitoring System calculates the energy balance fluxes at the earths surface. As intermediate products also the surface temperature and the temperature at the top of the atmospheric boundary layer are calculated. In the scope of the currently running CEWBMS project, much effort has been put in creating a new product; the temperature at observation height (1.5 meters). The spatially continuous temperature data will particularly satisfy users in agro- and hydro-meteorological fields, especially for the many parts of the world where the availability of meteorological data is limited. To see validation results of the temperature at observation height, click here.

Example: Mean temperature at observation height for the 3rd decade of September 2001.

Green=6°C, Yellow=16°C, Red=25°C

The China Energy and Water Balance Monitoring System (CEWBMS)

The Energy and Water Balance System, as described on our methodology page, is also implemented in China at the China National Satellite Meteorological Centre (CNSMC), the China National Desertification Monitoring Centre (CNDMC) and the Chinese Academy of Sciences – Institute of Geographical Sciences & Natural Resources Research (CAS-IGSNRR). Since the beginning of 2000, images of the GMS geostationay satellite are being received and energy balance products and early warning products are created. Below, two examples are shown of desertification indices. Left: Climatic Moisture Index (CMI) for the year 2001. Right: Soil Moisture Index (SMI) for the year 2001.  The CMI is defined as the ratio of rainfall and potential evapotranspiration, expressed in %, and indicates a climatic condition. The SMI is defined as the ratio of actual evapotranspiration and potential evapotranspiration, expressed in %, and indicates the actual desertification state of the ground.


To make it easier for interested visitors to evaluate our products, we have developed a software tool called ImageShow, which can be downloaded at our new sample download section. ImageShow allows you display our products as quantitative spatially continuous maps and offers some functionality for simple analysis. In principle, our generic binary data products can be imported in almost any Geographical Information System, but using ImageShow it will be easier for you to display and evaluate our full resolution samples. A number of these samples, showing full resolution crop growths conditions and drought indices for Africa, can be downloaded. Also a boundary overlay, which can be used in ImageShow, is available. Click on sample download in the link frame on the left to go to the improved download section.

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