The experiment of the effects of rainfall intensity and substrate depth of an extensive vegetated roof

Nowadays, extreme precipitation events are becoming more and more prevalent, which, in some
situations, can cause serious problems and damage. To avoid the impacts of extreme rainfall events,
blue-green infrastructure elements are used to retain and slow down stormwater runoff. Examples are
vegetated (green) roofs, widely considered a promising nature-based solution for urban stormwater
management.
This experiment is focused on studying the influence of the retention capacity and the depth of the
selected commercial substrate of extensive vegetated roofs. The rainfall intensity testing aims to
demonstrate and explore new insights into vegetated roofs during severe extreme precipitation. The
actual experimental process was performed under laboratory conditions, where extreme rainfall
intensities (2 - 4 mm/min) with a duration of 15 minutes were subsequently simulated using a rainfall
simulator. The main identifier of the quality and capability of the substrate used on the vegetated roof
is the amount of runoff captured from the simulated rainfall intensity. The measured outputs will be
used as inputs to predictions reducing stormwater runoff. The knowledge gained and the different
variations of the simulations can significantly help in constructing and designing vegetated roofs and
effective urban stormwater management.

Keywords: precipitation, retention capacity, vegetated roof, runoff,