Long-term post-event processes and major reactivation of a complex landslide : 2000–2023 evolution of the Ciprnik landslide, Julian Alps, Slovenia

Novak, Andrej (author), Vrabec, Marko (author), Šmuc, Andrej (author)

The Ciprnik complex landslide in the Planica valley (NW Slovenia) happened on 19. 11. 2000 as a translation slip-debris flow-hyperconcentrated flow event. It was triggered by a combination of the local geological structure (highly fractured beds dipping parallel to the surface), lithology (alternation of thin bedded carbonates and fine-grained clastics), and record-breaking monthly rainfall (613.6 mm in the month of the event). Twenty-three years later, on the night from 24. to 25. 10. 2023, large parts of the landslide reactivated during intense short-duration rainfall, which has a relatively common occurrence (104.2 mm in 24 h). We use 2006–2023 time series of photogrammetrically derived digital elevation models generated from aerial photographs and unmanned aerial vehicle surveys, sedimentological analysis, and meteorological data to (1) analyze decade-scale post-event processes on the Ciprnik landslide following the initial sliding event in November 2000 and (2) to study the October 2023 event and compare it to the November 2000 event. We find that after the initial November 2000 event, the area of the Ciprnik landslide remained unstable with an average annual erosion rate of 1000 to 3500 m$^3$ of sediment. The 2023 event measured 26,000 m$^3$ and, despite a different triggering rainfall, again occurred as a translation slip-debris flow-hyperconcentrated flow event exhibiting a strong fining down of sediment (from muddy-sandy-gravel to sandy-silt). This study demonstrates the complexity of triggering thresholds in the aftermath of the main mass movement event. Even in the later events, which have the same transport mechanisms as the original event, the triggering precipitation can differ considerably in duration and magnitude.

• Language: English
• Keywords: complex landslide, translational slip, debris flow, hyperconcentrated flow, UAV, granulometry
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: NTF - Faculty of Natural Sciences and Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2025
• Number of pages: Str. 4013-4027
• Numbering: Vol. 22, iss. 12
• PID: 20.500.12556/RUL-178847
• UDC: 55
• ISSN on article: 1612-510X
• DOI: 10.1007/s10346-025-02598-5
• COBISS.SI-ID: 246472963
• Publication date in RUL: 30.01.2026

Record is a part of a journal

• Title: Landslides : journal of the International Consortium on Landslides
• Publisher: Springer Nature, International Consortium on Landslides
• ISSN: 1612-510X
• COBISS.SI-ID: 2274913

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• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.