Measurements of erosion processes in the experimental catchment of the Dragonja River, SW Slovenia

Authors: Gregor PETKOVŠEK, Matjaž MIKOŠ
Citation: Acta hydrotechnica, vol. 21, no. 34, pp. 37-56, 2003.
Abstract: The paper presents and analyses the results of some of the measurements in the Rokava catchment, which is a part of the Dragonja catchment. Measurements were carried out mostly between autumn 2000 and spring 2002. The measured quantities included water discharge, suspended and bedload discharge, dynamics of sediment production from cliffs, and measurements of rainfall, which were used to compute rainfall and the runoff erosivity factor R. The results show that the mean annual suspended sediment yield is around 1500 tonnes, which is equal to 750 kg/ha/year. Cliffs’ activity was monitored with a combination of photogrammetric surveys and erosion pins, which gave us both the total sediment production from cliffs and its short-term dynamics. Cliffs are most active in late summer. They contribute approximately 100 tonnes of fine sediment into the stream network. Rainfall erosivity is highly variable, both spatially and temporally. The rainfall erosivity is highest in the period between July and November.
Keywords: experimental catchment, Dragonja, Rokava, sediments, cliffs, rainfall erosivity
Full text: a34gp.pdf