Author(s): Matjaz Mikos; Rok Fazarinc
Linked Author(s): Matjaž Mikoš
Keywords: Debris flows; Fluvial erosion; Natural hazards; River engineering; Sedimentation; Torrent control
Abstract: On November 17, 2000, the Stoze debris flow devastated the Koritnica River valley, a typical narrow alpine valley in W Slovenia. Around 400, 000 m3 of debris material were deposited along the debris flow pathway upstream the valley, and nearly 700, 000 m3 were deposited in the valley itself, locally with a thickness up to 10 m. An outline scheme for river engineering measures was adopted in order to stimulate natural river erosion processes. As a basis for this scheme, the results of a hydrologic analysis, granulometric analysis of debris deposits, and preliminary evaluation of cross-sectional sediment transport capacities were used. The form of the final river cross sections was also determined using results of mathematical modeling of possible future debris flows of the same magnitude as in November 2000. The selected channel bed widths were less than half of the normal bed widths prior to the event: 8 m for the Koritnica River (I ~ 2. 2 % , Q100 = 211 m3/s), and 3 m for the Predelica Torrent (I ~ 4. 6 % , Q100 = 77 m3/s) were excavated. Using this approach, in the first 4 years nearly half of the debris flow deposits have been eroded from the devastated area in the Koritnica River valley by natural processes of river erosion.
Year: 2005