Panta Rhei: promjena kretanja kamenog glečera Tschadinhorn (planinski lanac Hohe Tauern, Austrija), 1954–2017

• Published in: Kartografija i geoinformacije
• Main Authors: Kaufmann, Viktor, Sulzer, Wolfgang, Seier, Gernot, Wecht, Matthias
• Format: Article in Journal/Newspaper
• Language: Croatian; English
• Published: Croatian Cartographic Society 2019
• Subjects: permafrost; kameni glečer; brzina kretanja; fotogrametrija; UAV; promjena okoliša; Tschadinhorn; rock glacier; flow velocity; photogrammetry; environmental change
• Online Access: https://hrcak.srce.hr/219013; https://hrcak.srce.hr/file/319712; https://hrcak.srce.hr/file/319713

U radu se prikazuje rekonstrukcija kinematike kamenog glečera Tschadinhorn upotrebom viševremenskih konvencionalnih (mjernih) fotografija snimljenih iz zraka (1954–2015) i dodatnih nemjernih fotografija snimljenih iz zraka (2016, 2017) bespilotnim letjelicama (unmanned aerial vehicles – UAV). Letjelica s rotirajućim krilima (hexacopter twinHEX v.3.0) upotrebljena je 2016. godine, a letjelica s nepokretnim krilima (QuestUAV) upotrebljena je 2017. Povijesni slikovni podaci dobiveni su od Austri­jskog federalnog ureda za metrologiju i izmjeru (Bundesamt für Eich- und Vermessungswesen – BEV). Za svako su razdoblje izračunani digitalni ortofoto (DOP) i digitalni model reljefa (digital relief model – DTM). Precizno geo­re­­­­­­ferenciranje slikovnih podataka provedeno je u austrijskom koordinatnom su­­stavu Gauss- Krüger M31 upotrebom aerotriangulacija (AT) do­bi­venih od BEV-a i dodatnim kontrolnim točkama na tlu (ground control point – GCP) geodetski izmje­re­nih tijekom obaju izmje­ra bespilotnim letjelicama. Analiza otkrivanja promjena rezultirala je viševremenskim dvo­di­menzi­ona­lnim poljem brzina kre­tanja. Nakon toga, podaci su sređeni kako bi se dobio jednostavniji grafički prikaz brzine koji jasno po­kazuje razvoj brzine kretanja kamenog glečera. Najveća prosječna godišnja brzina kretanja od 3,28 metra u godini dobivena je u razdoblju 2014– 2015, dok je najmanja godišnja brzina od 0,16 metra u godini opažena u razdoblju 1969–1974. Na grafičkom prikazu brzine također se vidi da je razdoblje 1954–2009 bilo karakterizirano uglavnom umjerenom aktivnošću (0,16 – 0,79 metra u godini) te da od 2009. prevladavaju mnogo veće brzine kretanja. Trenutačna vrijednost za 2016–2017 iznosi 1,92 metra u godini. In this paper we present a reconstruction of the kinematics of the Tschadinhorn rock glacier using multi-temporal conventional (metric) aerial photographs (1954–2015) and additional non-metric aerial photographs (2016, 2017) taken with in-house unmanned aerial vehicles (UAVs). A rotary-wing aircraft (hexacopter twinHEX v.3.0) was used in 2016 and a fixed-wing aircraft (QuestUAV) in 2017. The historical image data was acquired from the Austrian Federal Office of Metrology and Surveying (BEV). Both a digital orthophoto (DOP) and a digital terrain model (DTM) were computed for each given epoch. Precise georeferencing of the image data was carried out in the Austrian Gauss-Krüger M31 coordinate system using available aerotriangulations (ATs) of BEV and additional ground control points (GCPs) measured geodetically during both UAV campaigns. Change detection analysis provided multi-temporal 2D flow velocity fields. Subsequently, these data were collated to produce a simpler velocity graph showing clearly the temporal evolution of the flow velocity of Tschadinhorn rock glacier: A maximum mean annual flow velocity of 3.28 m/year was obtained for 2014–2015, while the lowest annual flow velocity of 0.16 m/year was observed for 1969–1974. The velocity graph also revealed that 1954–2009 was characterized by generally moderate activity (0.16 – 0.79 m/year) and that much higher flow velocities have prevailed since 2009. The present value for 2016–2017 is 1.92 m/year.