Effect of rainstorm structure on runoff

The main question arising in this context is why the increase in extreme rainfall events is not always translated into an increase in flood events. To answer this question, it is necessary to investigate the effects of temporal distribution of rainfall intensities during rainfall events, and of antecedent water content in the soil profile, on runoff generation and accumulation.

This study shows how temporal patterns of individual rainstorms affect runoff formation under different antecedent soil water content conditions. We simulated the runoff outcome of rainfall time series characterized by different statistical moments (mean, standard deviation and skewness) on a Mediterranean loamy soil. The results show that ponding time and time to peak runoff decreased with mean rainfall rate and standard deviation, and increased with storm skewness and as the soil profile was drier.