Areal reduction factor. The effect of the return period
For the study and modeling of hydrological phenomena both in urban and rural areas, a proper estimation of the areal reduction factor (ARF) is crucial. The ARF is defined as the ratio between the average rainfall occurring on a specific area and the point rainfall. In literature there exist several methodologies to estimate this ratio, as a consequence the corresponding ARFs have different properties. Spite the importance of the topic for the definition of design rainfall events, the ARF estimation has still some open issues.