According to the PDSI index, at the end of October, there was a significant decrease in the area and intensity of the meteorological drought throughout the continent. However, some places in Alentejo and Algarve are still experiencing meteorological drought. Of note:
In terms of percentage distribution by classes of the PDSI index in the mainland, at the end of October it was verified:
PDSI Index (Palmer Drought Severity Index) was developed by Palmer (1965) and implemented and calibrated for mainland Portugal (Pires, 2003).
This index is based on the concept of the water balance taking into account data on the amount of precipitation, air temperature and available water capacity in the soil and allows the detection of periods of drought by classifying them in terms of intensity (weak, moderate, severe and extreme).
Table - Classification of the PDSI index for dry and rainy periods
greater than or equal to 4,0
3,00 to 3,99
2,00 to 2,99
1,00 to 1,99
-0,99 to 0,99
-1,99 to -1,0
-2,99 to -2,0
-3,99 to -3,0
less than or equal to -4,00