Page - 384 - in ExtremA 2019 - Aktueller Wissensstand zu Extremereignissen alpiner Naturgefahren in Österreich

© 2020, Vandenhoeck & Ruprecht GmbH & Co. KG, Göttingen ISBN Print: 9783847110927 – ISBN E-Lib: 9783737010924 KenntnisvergangenerEreignisse inVerbindungmit einemerhöhtenProzessverständnis undgezielteingesetztenMonitoringsystemen,Frühwarnsystemen,raumplanerischenund – soweitwirtschaftlichvertretbar – technischenMaßnahmen ist der Schlüssel zurMini- mierungdermitderartigenMassenbewegungenverbundenenGefahrenundRisiken. Abstract Extremely rapidrockslidesandrockavalancheswithgenerally largeenergies andtravel distances can put human life at risk and destroy property and infrastructure. Slow- or moderate-velocity rock slides and earth/debris flows are often characterized by re- activation and acceleration phases and can cause large damages, whereas people can usually escape. In theAlps, susceptible areas for all of the consideredprocesses arewell known at regional scale due to their lithology, structural geology, topography, hydro- geology, geomechanics, and event history. However, the spatio-temporal prediction of specificextremeeventsremainsachallengedespitemoderninvestigationandmonitoring techniques: failuremechanismsare complex in space and time, and they arenot always directly linked to obvious, measurable triggering factors. In many cases, progressive processes suchas subcritical crackgrowthor very slowdeformations,whichare in turn influencedbyother factors (precipitation, groundwater, temperature, in-situ stress, dy- namic loading,permafrost, etc.) acting intherockmass.They lead–onbroadlyvarying timescales–totheexceedanceofrockmassstrengthandthustoslopefailureor, forpre- existing rock slides, to accelerationphases. Furthermore, rock slides or rockavalanches candevelop into cascading landslideprocesses.An improved levelofknowledgeonpast events in connectionwith an increasedprocess understanding andwell-designedmon- itoring andearlywarning systems, spatial planning and–as far as economically justifi- able– technicalmeasures is the key tominimize the hazards and risks associatedwith these typesof landslides. Kernaussagen – AnfälligeGebietegegenüberFelsgleitungen,FelslawinenoderErd-bzw.Schuttströmen sind indenAlpenhäufigbekannt. – DiekonkreteVorhersagespezifischerExtremereignisse inRaumundvoralleminZeit stellt nachwievoreinegroßeHerausforderungdar. – Eine Kombination verschiedener Untersuchungs- undÜberwachungsmethoden ist nötig, ummöglicheExtremereignisse zu erkennen, entsprechendvorherzusagenund damitdasRisikobzw.möglicheVerluste zuminimieren. KeyPoints – IntheEuropeanAlps,locationswhicharesusceptibletorockslides,rockavalanches,or earth/debris flowsareoftenknown. – Thepredictionofspecificextremeeventsinspaceandparticularintimestillremainsa big challenge. – A combination of various investigation andmonitoringmethods is required to ap- propriately localise and forecast potential catastrophic events and to reduce the risk and theassociated losses. Felsgleitung, FelslawineundErd-/Schuttstrom384 Open-Access-Publikation im Sinne der CC-Lizenz BY-NC-ND 4.0