XXV Convegno Nazionale di Agrometeorologia

XXI Convegno Nazionale di Agrometeorologia (Roma, 19-21 Giugno 2018)

Oral presentation on “Predicting, on a seasonal scale, the triggering and persistence of extreme drought events: the case study of the Po river basin

In the last 15 years, the northern regions of Italy have experienced some prolonged periods of intense drought. In this context, drought forecasting can be an effective tool for optimizing water resources and activating appropriate adaptation actions. However, the seasonal forecasts for the anticipation of possible drought conditions are challenging, due, in general, to the limited predictive ability of seasonal predictions over the Euro-Mediterranean region and, in particular, to the limited ability of dynamical models in predicting blocking onset and frequency at all forecast timescales, being these the large scale dynamical features leading to the occurrence of local droughts.

For this reason, the identification of the best timeframes and related drought forecasting opportunities can be an innovative and effective approach for the drought risk manager, especially in the agronomic field.

The present work explores the potential relationship between the SPI (Standardized Precipitation Index) calculated over multiple time frames (from 1 to 36 months) with an equivalent river discharge indicator, SQI (Standardized Discharge River Index) for the Po river basin from 1961 to 2022. Specifically, pairwise correlations between SPI and SQI of different time frames are explored, with SPI from zero to 4 months ahead of the SQI reference month. The results show significant correlations between SPI and SQI of equivalent time frames, with advances of 1 and 2 months. The explorative approach shown here provides insight into the many forecasting opportunities that can be achieved. For instance, good results were obtained between SPI5 in May and SQI5 in June (i.e., SPI one month early, R2 = 0.81) and SPI6 in June and SQI6 in August (i.e., SPI 2 months early, R2 = 0.84).

This approach can help to increase the endowment of useful instruments to increase the resilience of the territories, with a strong agricultural vocation and of national importance, in the face of an increasing risk of drought.

Di Paola A.1, Pavan V.2, Magno R.1, Di Giuseppe E.1, Quaresima S.1, Rocchi L.1, Pasqui M.1

1IBE – CNR (Institute of BioEconomy of the National Research Council).
2ARPA ER (Agenzia Regionale Prevenzione Ambientale Emilia-Romagna, Servizio Idrometeoclima – Unità climatologia e previsioni di lungo termine).

Paper (PDF)