BEGIN:VCALENDAR VERSION:2.0 PRODID:-//pretalx//talks.osgeo.org//foss4g-it-2026//talk//NKYMZ9 BEGIN:VTIMEZONE TZID:CET BEGIN:STANDARD DTSTART:20001029T040000 RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=10 TZNAME:CET TZOFFSETFROM:+0200 TZOFFSETTO:+0100 END:STANDARD BEGIN:DAYLIGHT DTSTART:20000326T030000 RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=3 TZNAME:CEST TZOFFSETFROM:+0100 TZOFFSETTO:+0200 END:DAYLIGHT END:VTIMEZONE BEGIN:VEVENT UID:pretalx-foss4g-it-2026-NKYMZ9@talks.osgeo.org DTSTART;TZID=CET:20260710T153000 DTEND;TZID=CET:20260710T155000 DESCRIPTION:Rockfalls are rapid\, high-energy slope processes that can seve rely affect buildings\, infrastructure\, and human safety\, particularly w here steep rocky slopes interact with urbanized environments. Their assess ment is especially challenging at medium scale\, where large territories m ust be analyzed through simplified but reliable procedures\, and where the recurrence of different rockfall scenarios should be explicitly considere d. In this context\, preliminary risk analyses are essential to support la nd-use planning\, mitigation prioritization\, and the identification of se ctors requiring more detailed investigations.\nThis study presents a GIS-b ased procedure for preliminary time-dependent rockfall risk assessment\, d eveloped to support spatially distributed risk screening through the expli cit inclusion of temporal probability. The workflow is organized in two ma in phases within an open-source QGIS environment. The first phase concerns hazard analysis and is performed using the QPROTO Plugin (Castelli et al. \, 2021)\, adopted to estimate potential invasion areas and characterize r ockfall intensity for different block-volume scenarios through a simplifie d physical-based estimation of the kinetic energy of the block.\nThe secon d phase concerns risk assessment and is carried out through the QRADE plug in\, which applies the IMIRILAND methodology (Bonnard et al.\, 2004) to in tegrate hazard outputs with the vulnerability and value of exposed element s. Starting from a hazard dataset representing block kinetic energy\, QRAD E assesses the vulnerability of exposed elements using predefined but full y customizable tables derived from the literature (Torsello et al.\, 2022) . Exposed elements can be provided by the user or downloaded automatically directly from OpenStreetMap (OSM). By leveraging OSM’s taxonomy and tag s\, QRADE assigns a specific vulnerability rating to each identified eleme nt (e.g.\, buildings\, roads\, or infrastructure). Based on classification s of the elements’ value\, proposed by the plugin but also fully customi zable\, a risk index is then calculated for each element. \nWhen assessing the vulnerability and value of the elements\, physical aspects (damage to structures or buildings) and social aspects (harm to people) are consider ed separately. The final result then consists of three risk maps: Physical Risk\, Social Risk\, and Total Risk\, which is equal to the sum of the fi rst two.\nTo account for the time-dependent component of risk\, different rockfall volume scenarios can be associated with probabilities of occurren ce over selected reference periods\, through a probabilistic formulation b ased on historical event recurrence. This allows the procedure to move bey ond a purely spatial assessment by considering not only the expected effec ts of the phenomenon\, but also its likelihood over time. In this way\, th e framework provides a more informative basis for preliminary decision-mak ing in comparison with time-independent approaches.\nThe methodology is ap plied to the Palermo area in southern Italy\, considered a representative case study given the interaction between steep rocky slopes and exposed ur ban elements\, as well as the need to develop and test practical tools for evaluating the effects of climate change in the Mediterranean context. Th e proposed approach produces hazard and risk maps for multiple scenarios a nd offers a rapid\, transparent\, and scalable framework for the prelimina ry evaluation of rockfall-prone areas. Although intended as a screening-le vel methodology\, it provides useful support for identifying critical sect ors\, guiding subsequent site-specific analyses\, and informing mitigation and risk-management strategies. More broadly\, the procedure contributes to the development of operational GIS-based tools for preliminary time-dep endent geohazard risk assessment in data-limited contexts.\n\nReferences\n Castelli M.\, Torsello G.\, Vallero G.\, 2021. Preliminary Modeling of Roc kfall Runout: Definition of the Input Parameters for the QGIS Plugin QPROT O. In: GEOSCIENCES\, vol. 11. https://doi.org/10.3390/geosciences11020088\ nTorsello G.\, Vallero G.\, Milan L.\, Barbero\, M.\, Castelli M.\, 2022. A Quick QGIS-Based Procedure to Preliminarily Define Time-Independent Rock fall Risk: The Case Study of Sorba Valley\, Italy. In: GEOSCIENCES\, vol. 12. https://doi.org/10.3390/geosciences12080305\nBonnard Ch.\, Forlati F.\ , Scavia C. (eds)\, 2004. Identification and mitigation of large landslide risks in Europe: advances in risk assessment. A.A. Balkema\, ISBN 90 5809 598 3 DTSTAMP:20260614T172141Z LOCATION:Aula accademica SUMMARY:A GIS-based procedure for preliminary time-dependent rockfall risk assessment at medium scale - Stefano Campus\, Marta Castelli\, Seyedmostaf a Moeini URL:https://talks.osgeo.org/foss4g-it-2026/talk/NKYMZ9/ END:VEVENT END:VCALENDAR