Cumulative differences NDVI: comparison between the accumulated vegetation indices from January to May 2007 and those of the historical average

The map of cumulative differences of NDVI (Standardised Difference Vegetation Index) from January to May 2007, included in the study of Monitoring the Annual Evolution of Crops and Harvests, contains the percentage differences of the vegetation indices accumulated in the period from January to May 2007 and the corresponding values of the average year (average of the series of years for which images are available). To obtain these results, the Ministry of Agriculture and Fisheries, Food and Environment (MAPAMA) has a system for monitoring the evolution of dry and grassland crops, based mainly on the information provided by vegetation indexes (NDVI) generated with daily satellite images NOAA-AVHRR. This system has been in operation since 1993, paying particular attention to the detection and tracing of drought situations throughout successive agricultural campaigns, in order to provide for the necessary measures to mitigate their effects. The system is in operation between the months of January and June, a period in which the studied crops are developed. The study is carried out in the autonomous communities of Navarra, Aragon, Catalonia, Castile and Leon, La Rioja, Madrid, Castilla La Mancha, Valencian Community, Andalusia, Murcia Region, Extremadura and Balearic Islands, as they comprise almost all dry crops and grasslands.