Recently burnt areas typically reveal strong to extreme hydrological responses, as a consequence
of loss of protective soil cover and heating-induced changes in topsoil properties. Soil water
repellency (SWR) has frequently been referred to as one of the explanatory variables for fireenhanced surface runoff generation but this has been poorly demonstrated, especially at the
catchment scale. This study employs a process-based modelling approach to better understand
the relevance of SWR in the hydrological response of a small, entirely burnt catchment in central
Portugal, in particular by comparing hydrological events under contrasting initial conditions of dry
vs wet soils. The OpenLISEM model was applied to a selection of 16 major rainfall runoff events
that occurred during the first 2 post-fire years. The automatic calibration procedure resulted in
good model performance, but it worsened for validation events. Furthermore, uncertainty
analysis revealed an elevated sensitivity of OpenLISEM to event-specific conditions, especially
for predicting the events’ total and peak flows. Also, predicted spatial patterns in runoff poorly
agreed with the runoff observed in microplots. Model performance improved when events were
separated by dry and wet initial moisture conditions, particularly for wet conditions, suggesting
the role of variables other than initial soil moisture.info:eu-repo/semantics/publishedVersio
