Ricerc@Sapienza

Raindrop-impact-induced erosion starts when detachment of soil particles from the surface results from an expenditure of raindrop energy. Hence, rain kinetic energy is a widely used indicator of the potential ability of rain to detach soil. Although it is widely recognized that knowledge of rain kinetic energy plays a fundamental role in soil erosion studies, its direct evaluation is not straightforward. Commonly, this issue is overcome through indirect estimation using another widely measured hydrological variable, namely, rainfall intensity.

To retrieve the gamma drop size distribution (DSD) parameters from observed drop spectra, the most common approach is the method of moments (MM). However, the goodness of this method is still disputed. To assess its reliability, the aims of this paper are: (i) estimation of empirical values of rainfall rate (I) and kinetic energy (KE) from DSD measurements collected by a laser-optical disdrometer; (ii) estimation of gamma DSD parameters by MM and another widespread method, i.e.