Interception

Abstract Interception is a key process in hydrology that is receiving relatively little attention. It is the first process of the hydrological cycle that a raindrop experiences after falling from the sky, and hence, all subsequent processes depend on it. Neglect of the interception process can lead to serious modeling mistakes. Interception is defined as the evaporative process that feeds moisture back to the atmosphere shortly after the rainfall has ceased (within approximately 1 day). It is the evaporation from all surfaces that have been moistened by precipitation, including leaves, soil, mulch, rock, paved, and build‐up surfaces. Evaporation from interception can amount to a considerable part of all terrestrial evaporation, depending on the climate and region. The interception process behaves differently at different time scales. Formulas are presented for the computation of interception at short, daily, and monthly time scales.