• Dekadal Forage Maps
  • Year 2001
  • Year 2002
  • Year 2003
  • Year 2004
  • Year 2005
  • Year 2006
  • Year 2007
  • Year 2008

• Dekadal Forage Deviation Maps
  • Year 2001
  • Year 2002
  • Year 2003
  • Year 2004
  • Year 2005
  • Year 2006
  • Year 2007
  • Year 2008


• Zone Forage Maps


• Interactive Maps


• IRI Forecast Map

The Livestock Early Warning System (LEWS) has 9 zones in the IGAD region and each zone has over 30 monitored points. For each geo-referenced monitoring point,a multiple species rangeland plant growth model (PHYGROW) is parameterized with data (soils, plants and grazers).The model is then run with current satellite weather data ( http://cnrit.tamu.edu/rsg/rainfall/rainfall.cgi) to determine standing crop of the forage available (kg/ha) to grazing animals.  The model output is then compiled for each dekad (10-day intervals) and processed to produce spatially-explicit forage maps for the IGAD region and for each individual zone.  To develop surface maps, the model output (forage kg/ha) data is coupled with the Normalized Difference Vegetation Index (NDVI) and put into a geostatistical package (GS+) where an interpolation technique called co-kriging is used.  If a good correlation exists between the forage output from PHYGROW and the NDVI, then co-kriging allows a better estimation of forage production in areas between the monitored points.

Ground truthing to verify accuracy of maps is carried out by zonal monitors cutting, clipping, oven-drying and weighing of vegetation at the monitoring points, visual estimations from photo-guides and comparison with model results.