The rainfall event during the night of 10th-11th September 2007 caused strong erosion in the gully of Potovosca on the Island of Krk. In the main fan, two new gullies and two fans were formed. Those morphological changes have been mapped, measured and explained, across the drainage basin in terms of topography and precipitation intensity. The drainage basin morphology was studied using GIS that allowed comparison of morphological and dynamic relationships within the study area. In order to obtain the relative potential erosion intensity between different points in the basin, as well as to differentiate areas with areal (diffuse) erosion from those with dominant linear erosion, the Stream Power Index (SPI) was calculated. The drainage basin specifi c properties were further related to the event specifi c properties, precipitation intensity and hydrologic estimations. The rainfall intensities obtained, allow the calculation of discharge at the gully mouth and the defi nition of recurrent periods using the rational method. The rainfall- runoff event studied was also infl uenced by the relatively high Antecedent Precipitation Index (API). This allows explanation of the morphological consequences of the short-term event. Consequently the interrelationship between short-term and long-term events has been discussed. In addition, the physiography of the gully has been recently modifi ed by human interference, which has also infl uenced the morphological consequences of the aforementioned short-term rainfall event.