Areas affected by three recurrent negative precipitation anomalies (2000, 2003 and 2006)

(upper) Areas affected by three recurrent negative precipitation anomalies (as indicated in the graph: 2000, 2003 and 2006 during the period 1999–2010 based on the standardised precipitation index, a statistical correlation to recurrent anomalies through principal component analysis (PCA) of time series climatic data). The prevalence of recurrent negative precipitation anomalies in the Mediterranean area is very apparent. Such anomalies can also affect areas with traditionally humid climates.

(lower) The effect of these events on ecosystem productivity based on a change index: the steadiness index. This index addresses both the long-term trend and the net change of primary production calculated from satellite time series over the period in which the recurrent negative precipitation anomalies occurred (1999–2010). The areas in red denote regions with a stronger likelihood of decreased productivity relative to the ecosystem capacity.