The cartography of evapotranspiration and crop water deficits in Southern Italy has been prepared on the basis of data calculated with a semi-empirical model using the historical series of average monthly meteorological data available at the time the study was conceived. Although the results of its application are potentially less precise than those obtainable by using a mechanical model based on the laws of the water dynamics in the soil-plant-atmosphere system, the use of this method is today still justified in the planning and designing of large irrigation systems, especially in cases where reference is made to rather homogeneous agro-climatic situations and where input data is insufficiently detailed. This is quite a common condition in studies on a territorial scale.
The evapotranspiration maps have already been published in the review Irrigazione e Drenaggio (Ravelli and Rota, 1994) and have been posted in Chapter 2 of this site in a new computer-mapped version. The water deficit maps (net crop water requirements maps) of the main crops grown in Southern Italy (ISTAT, 1998) have been posted in Chapter 3.