3. Results
3.1. Rainfall events
In total 35 rainfall events were recorded over the rainy season in 2008 between May 15th and October 30th (Fig. 4). The rainfall was classified into non-erosive and erosive events. Each was in turn grouped in two categories according to the rainfall intensity (Fig. 5). The non-erosive events did not exceed an intensity of 2.75 mm h− 1. The category with the lowest rainfall intensity (≤ 0.75 mm ha− 1) was characterised by a little precipitation (Fig. 5). The second category with intensity > 0.75 and ≤ 2.75 mm ha− 1 had higher rainfall amounts. The two erosive rainfall categories had, as expected, higher intensities than the non-erosive ones. The category with intensity > 2.75–≤ 5 mm h− 1 showed, as the non-erosive categories, a positive correlation between the rainfall amount and duration (Fig. 5). In contrast, the rainfall amount of the category, which includes the strong rainfall events with intensities > 5 mm h− 1, was in negative correlation with the rainfall duration: higher precipitation was associated with shorter rainfall duration. The events of this category had in comparison to the rainfall events with intensity ≤ 5 mm h− 1 shorter rainfall durations, which did not exceed 2 h.