Spatial analysis techniques for mapping the annual surface runoff in Sicily under the Budyko’s framework

This work shows a new approach, based on the Budyko framework, for mapping the mean annual surface runoff and deriving the probability distribution of the annual runoff in arid and semi-arid watersheds. We analytically provide the annual runoff distribution as the derived distribution of annual rainfall and potential evapotranspiration. The simulated long-term annual runoff and its distribution have been compared with historical records at several gauged stations, obtaining satisfactory matching.