At the European level, the data relating to the long-term rainfall still confirm a critical situation widespread in many countries, with a more or less important extension. As for Italy, October was also a record month. Average temperatures were the second highest since 1800, with a national anomaly of just over + 2 ° C, while in the north the positive anomaly of over 3 ° C was the highest. The rainfall was clearly below average, with about -45% at the national level, and the severe-extreme drought relative to the month of October alone affected the southern Po Valley and a large part of central Italy. In addition, despite the rains in September, several areas of the North remain in long-term severe conditions, as well as part of Calabria.
From the regional analysis it emerges that the September rains had an influence in reducing the rainfall deficit only in the short and partly in the medium term. In the long term (12-24 months), however, the northern regions and Calabria are still affected by severe-extreme drought, in particular Piedmont, with about 50% of the territory exposed to the phenomenon. Consequently, the % of the population exposed to prolonged drought also continues to be high, with almost 40% compared to the accumulated deficit in the last 12 months. From an agricultural point of view, irrigated land is still the most exposed in the long term, while in the very short term the rainfall deficit has affected practically all types, from agriculture to meadow-pasture.
SPI (Standardized Precipitation Index)
The very short-term SPI index clearly shows the large rainfall deficit accumulated over a large part of central and northern Italy, while the areas where rainfall was most intense are evident in the quarter. In the medium and even more so in the long term, drought persists in several areas of the north, but also in the south.
ESI (Evaporative Stress Index)
The Evaporative Stress Index of the 4 weeks of October highlights the areas where there is still a condition of low soil moisture and vegetative stress. These areas are still concentrated in the north and are in line with the strong thermal anomalies of the month.
TCI (Temperature Condition Index)
The TCI index for the first half of the month shows higher temperature conditions in the north and in some areas of southern Italy. PS: The possible lack of information on different areas is linked to the greater cloud cover in the autumn-winter period.
VCI (Vegetation Condition Index)
The vegetation stress index calculated on forest areas shows low values on various areas of the Alps, in particular Valle d’Aosta and Trentino Alto-Adige (in the latter case probably due to the combined action of drought and parasitic attack of the Bostrico typographer) and also on the northern Apennines, Tuscan and Sardinian hills and some southern areas.
VHI (Vegetation Health Index)
The comprehensive VHI index indicates stressful situations in the forestry field in some areas of the Alps, western Po and northern Apennine woods and in southern Calabria and eastern Sicily.