Minimum Inter-event Time to identify independent rainfall events in urban catchment scale

For many hydrologic analyses, planning or design problems, reliable rainfall estimates are necessary. For this reason, an accurate estimation of storm event properties is central to continuous simulation of rainfall. Rainfall is generally noted as single events or storms where the beginning and the end are defined by rainless of particular size duration called Minimum Inter-event Time (MIT). Starting from a critical study of the state of the art, this paper intends to investigate the definition of MIT for rainfall events shorter than an hour that, on an urban scale, are the most critical for designers, planners and operators of urban drainage system. All event characteristics such as depth and mean rain rate, are influenced by the choice of the value of MIT. This paper reviews the range of approaches used in literature and after this, based on a year of pluviograph records on an urban catchment, proposes a value of MIT according to catchment network entry time.