Prediction of Climatic Change for the Next 100 Years in the Apulia Region, Southern Italy

The impact of climate change on water resources and use for agricultural production has become a critical question for sustainability. Our objective was investigate the impact of the expected climate changes for the next 100 years on the water balance variations, climatic classifications, and crop water requirements in the Apulia region (Southern Italy). The results indicated that an increase of temperature, in the range between 1.3 and 2,5 °C, is expected in the next 100 years. The reference evapotranspiration (ETo) variations would follow a similar trend; as averaged over the whole region, the ETo increase would be about 15.4%. The precipitation will not change significantly on yearly basis although a slight decrease in summer months and a slight increase during the winter season are foreseen. The climatic water deficit (CWD) is largely caused by ETo increase, and it would increase over the whole Apulia region in average for more than 200 mm. According to Thornthwaite and Mather climate classification, the moisture index will decrease in the future, with decreasing of humid areas and increasing of aridity zones. The net irrigation requirements (NIR), calculated for ten major crops in the Apulia region, would increase significantly in the future. By the end of the 21st Century, the foreseen increase of NIR, in respect to actual situation, is the greatest for olive tree (65%), wheat (61%), grapevine (49%), and citrus (48%) and it is slightly lower for maize (35%), sorghum (34%), sunflower (33%), tomato (31%), and winter and spring sugar beet (both 27%).