Dieser Beitrag beschreibt die photogrammetrischen und geodätischen Arbeiten zur Erfassung der Kinematik der Hangrutschung im Blaubachgraben (Gemeinde Krimml, Salzburg, Österreich) für den Zeitraum 1953 bis 2006. Das dargestellte Methodenspektrum zielt darauf ab, einerseits mit Luftbildzeitreihen das zeitlich zurückliegende Bewegungsverhalten des Rutschhanges flächendeckend und andererseits die aktuelle Bewegung durch geodätische Einzelpunktmessung zu erfassen.
Die diesbezüglichen Arbeiten wurden vom Forsttechnischen Dienst für Wildbach- und Lawinenverbauung, Gebietsbauleitung Pinzgau, Zell am See, Bundesland Salzburg in Auftrag gegeben. Die Durchführung oblag dem Institut für Fernerkundung und Photogrammetrie (Projektleitung) und dem Institut für Navigation und Satellitengeodäsie, beide TU Graz.V. Kaufmann and R. Ladstädter
Institute of Remote Sensing and Photogrammetry
Graz University of Technology, A-8010 Graz, Austria
e-mail: viktor.kaufmann@tugraz.at
Abstract
Doesen rock glacier (46°59'N, 13°17'E, altitude range 2339-2650
m, width 150-300 m, length 1000 m) is located in the Ankogel group
of the Hohe Tauern range in Austria. The rock glacier has been the
subject of multi-disciplinary research work since 1994. For
example, the kinematics of Doesen rock glacier has been studied by
means of geodetic surveys and remote sensing techniques, i.e.,
photogrammetry and satellite-based differential SAR
interferometry.
The 3D motion field of Doesen rock glacier was photogrammetrically
obtained from multi-temporal aerial photographs from various
epochs between 1954 and 1998. This heterogeneous set of
photographs was evaluated twice, (1) by means of visual tracking
of prominent surface particles (boulders) in the 3D stereomodels
and (2) by applying automatic image matching techniques. The
latter method, however, was not successful from a practical point
of view, since the photogrammetric scanner used for digitizing the
aerial photographs introduced geometric errors in the scans which
could not be eliminated during the evaluation process.
The present paper describes a second attempt to apply the same
algorithms (ADVM software) to the newly digitized aerial
photographs, this time using an UltraScan 5000 photogrammetric
scanner of Vexcel Imaging Austria. We will briefly outline our
approach of measuring 3D displacement vectors, and the practical
work and the results obtained will be presented. A comparison of
the results of the two photogrammetric evaluation processes, i.e.,
manual mapping and image matching, is given.
V. Kaufmann (1), R. Ladstädter (1) and G. Kienast (2)
(1) Institute of Remote Sensing and Photogrammetry
(2) Institute of Navigation and Satellite Geodesy
Graz University of Technology, A-8010 Graz, Austria
e-mail: viktor.kaufmann@tugraz.at
Abstract
Doesen rock glacier (46°59' N, 13°17' E, altitude range 2339-2650
m) is located in the Ankogel group of the Hohe Tauern range in
Austria. The first permafrost related studies including
geomorphological mapping and geophysical investigations were
carried out in the early 1990s by the Institute of Geography and
Regional Science of the University of Graz. In 1995, the Institute
of Remote Sensing and Photogrammetry and the Institute of
Navigation and Satellite Geodesy (both Graz University of
Technology) commenced geodetic, photogrammetric and cartographic
work in order to obtain information on the kinematic state of the
rock glacier and to create more accurate maps of the area of
interest. Furthermore, satellite-based differential SAR
interferometry was applied to obtain additional geomorphometric
information. In this paper we want to (1) give a short summary of
the work carried out in the last 10 years, based mainly on
literature references, and will (2) present an analysis of the
photogrammetric and geodetic measurements carried out at Doesen
rock glacier using tables, graphs and thematic maps. The geodetic
analysis will include 34 object points and additional points of 4
profile lines of the rock glacier. These points were measured
every year in August during the last 10 years, with one
interruption in 2003.
V. Kaufmann and R. Ladstädter
Institute of Remote Sensing and Photogrammetry
Graz University of Technology, A-8010 Graz, Austria
e-mail: viktor.kaufmann@tugraz.at
Abstract
The effects of (monochromatic and chromatic) lens aberrations in
optical imaging are well documented in the literature. These
geometrical imperfections are caused by the physical parameters of
the optical system (lens) of the photographic camera and apply to
both analog and digital cameras. All these aberrations produce
lateral distortions (geometric errors) and/or longitudinal
distortions (image blur) in one way or another. In this paper we
focus on the elimination of the effect of lateral chromatic
aberration within a post-processing step after image acquisition.
This task has already become a vital topic with the advent of
digital (consumer) cameras. Many references can be found in the
World Wide Web. Several methods, from simple heuristic to more
stringent ones, are proposed by the user community. Since the
usage of digital consumer cameras (SLR or compact cameras) in
documentation and mapping of cultural heritage is becoming more
and more wide-spread, the present topic should be discussed in
more detail. Color fringes are inherent to all analog and digital
(color) photographs taken by cameras for which chromatic
aberration is not sufficiently corrected for. The width of color
fringes, mainly introduced by lateral chromatic aberration, is
smallest around the image center and greatest in the corners of
the photographs. The authors have developed a computer-based
procedure to precisely determine the geometric distortions of the
red and blue image channel (plane) in comparison to the green
reference channel. Least-squares matching is employed at distinct
corner points found by an interest operator in order to measure
point displacements. The paper also describes how these
measurements can be carried out using a commercial software, i.e.
PhotoModeler 5.0. In a first approximation the three RGB color
channels differ in scale, i.e. they are radially displaced.
Originally, the DistCorr software has been developed in
order to compensate for lens distortion to obtain perfect
central-perspective images. The software mentioned was readily
modified for correction of lateral chromatic aberration. As a
result, the geometrically re-scaled red and blue image planes are
registered to the green one. The amount of image displacement of
the two color channels can be specified as an additive correction
to the linear parameter of the radial-symmetric lens distortion
formula. Lateral color fringes can thus be eliminated to a great
extent with this simple method. This paper also presents examples
of practical investigations. Three lenses (17 mm, 20 mm, 50 mm) of
a digital consumer camera, i.e. a Nikon D100 SLR with 6
Megapixels, were analyzed. The results obtained are presented
numerically and graphically. An outlook on further improvements in
the elimination of color fringes is given at the end of the
paper.
M. Avian
Institute of Geography and Regional Sciences
University of Graz, A-8010 Graz, Austria
e-mail: m_avian@yahoo.com
V. Kaufmann
Institute of Remote Sensing and Photogrammetry
Graz University of Technology, A-8010 Graz, AUstria
e-mail: viktor.kaufmann@tugraz.at
G.K. Lieb
Institute of Geography and Regional Sciences
University of Graz, A-8010 Graz
e-mail: gerhard.lieb@uni-graz.at
Abstract
The Hinteres Langtalkar (Gössnitztal, Hohe Tauern, Austria) rock
glacier has been part of a complex transportation system of debris
and ice since the beginning of the Holocene and shows the highest
creep rates of all rock glaciers measured in the Hohe Tauern
Range. Results of movement analysis show that the entire rock
glacier behaves very differently at different zones and that
sudden temporal and spatial changes of velocity rates are a
typical feature. Zones with high rates occur close to rather
inactive zones and zones with low rates have rapidly accelerated
within years. The increase in movement rates over time is probably
caused by topography. These studies – especially the measurement
of surface velocities and elevational changes – allow a
differentiation of the rock glacier and a first attempt of a
morphogenetic interpretation. In this context, it is important
that the innermost part of the cirque was covered by a small
cirque glacier during the Little Ice Age advance. This cirque
glacier created a moraine complex, which obviously contributes to
the material supply of the rock glacier. A first estimation of
transportation rates is possible with the help of the measurement
results available, leading to a probable age of at least 4000
years.
G.K. Lieb
Institut für Geographie und Raumforschung
Universität Graz, A-8010 Graz
e-mail: gerhard.lieb@uni-graz.at
V. Kaufmann
Institut für Fenerkundung und Photogrammetrie
Technische Universität Graz, A-8010 Graz
e-mail: viktor.kaufmann@tugraz.at
M. Avian
Institut für Geographie und Raumforschung
Universität Graz, A-8010 Graz
Abstract
Hinteres Langtalkar (Schober Mountains, Hohe Tauern National
Park) - an example of complex morphodynamics in the high mountain
zone of the Central Alps.
This paper discusses geomorphodynamic processes in a cirque
(2350-3000 m a.s.l.) under permafrost conditions. It is shown on
the enclosed map (scale 1:5,000). These processes were studied
over an extended period by means of photogrammetric and geodetic
data as well as cartographic documentations. In this way a
transport system of debris could be identified that formed an
excellent example of a rock glacier advancing down a steep slope.
These findings appear to prove that the geomorphological features
in this cirque kept developing during all off the Holocene.
Zusammenfassung
Die Arbeit diskutiert geomorphodynamische Prozesse unter Permafrostbedingungen in einem Kar (2.350-3.000 m), das in der beiliegenden KArte 1:5.000 dargestellt ist. Diese Prozesse werden auf Grundlage photogrammetrischer und geodätischer Messungen sowie kartographischer Dokumentation untersucht. Auf diese Weise wird ein Schutttransport-System mit einem gut entwickelten Blockgletscher erkennkar, der über einen Steilhang hinab vorstößt. Es wird die Vermutung begründet, dass die Entwicklung der heutigen Formenwelt im untersuchten Kar das ganze Holozän über gedauert hat.
F.W. Leberl
VEXCEL Corporation
Boulder, CO 80301
Viktor Kaufmann
Research Center Joanneum
A-8010 Graz, Austria
Glen G. Gustafson
James Madison University
Harrisonburg, VA
Matt Stevens and Erwin Kienegger
VEXCEL Corporation
Boulder, CO 80301
Abstract
Computer-assisted photo-interpretation is a recent development
supported by the advent of numerous interpretation stations. A
unique universal station is VIDARS - manufactered by the Richards
Corporation of McLean, Virgina - since it has recently been
equipped with a new software system that incorporates complex
photogrammetric mensuration capabilities. Photo-interpreters
typically find it difficult to perform mensuration tasks;
therefore the implementation of the photogrammetric functions must
not burden the user with a need to unterstand photogrammetric
theories. This paper illustrates a difficult application of VIDARS
to sector-scan panoramic film (Long Range Aerial Panoramic -
LOROP) imagery and will show how well the user can perform target
positioning tasks within his interpretation work.
F. Leberl, E. Kienegger, C. Council
Vexcel Corporation
Boulder, CO 80301
Viktor Kaufmann
Technical University Graz
A-8010 Graz, Austria
Glen G. Gustafson
James Madison University
Harrisonburg, VA
Abstract
Long range oblique photography (LOROP) has hardly a tradition of
use in precision measurements. However, such measurements are
feasable. Typically LOROP imagery is the result of some form of
scanning motion from the horizon down; this results in either a
classical "sector scan" panoramic image, or in a sequence of
individual central perspective frame photographs.
We have created a software system that permits to make
measurements from such imagery, either in the classical mode of
photo-interpreters or with the more rigourous approach of
analytical photogrammetry. It employs a hardware system created
for reconnaissance-type photointerpretation. This paper describes
the scope of the system.
Viktor Kaufmann
Institute of Remote Sensing and Photogrammetry
Graz University of Technology
Steyrergasse 30, A-8010 Graz, Austria
Tel.: +43 316 873-6336, Fax: +43 316 873-6337
e-mail: viktor.kaufmann@tugraz.at
Abstract
In diesem Aufsatz wird über die quantitative Erfassung der
Morphodynamik des besonders aktiven Blockgletschers Hinteres
Langtalkar (Schobergruppe, Nationalpark Hohe Tauern, Österreich)
mittels digital-photogrammetrischer und geodätischer Methoden
berichtet. Repräsentative Ergebnisse der durchgeführten Arbeiten
sind in einer kombinierten Bild-Strichkarte, welche sich aus einer
Luftbildkarte 1:5 000 und weiteren thematischen Nebenkarten
zusammensetzt, kartographisch aufbereitet.
On the Topography and Morphodynamics of the Hinteres Langtalkar Rock Glacier (Schober Group, Hohe Tauern National Park, Austria)
The morphodynamics of the highly active Hinteres Langtalkar rock
glacier (Schober Group, Hohe Tauern National Park, Austria) is
documented by means of digital photogrammetry and geodetic survey.
Selected results of the practical investigations are presented
cartographically in a combined image-line map which consists of a
orthophoto map at 1:5,000 scale and other collateral maps.
Viktor Kaufmann & Richard Ladstädter
Institute of Remote Sensing and Photogrammetry
Graz University of Technology
Steyrergasse 30, A-8010 Graz, Austria
Tel.: +43 316 873-6336, Fax: +43 316 873-6337
e-mail: viktor.kaufmann@tugraz.at
Abstract
The mapping of glacier fluctuations is an important task of
environmental research. Several methods of glacier mapping on a
local, regional and global scale are available. From a historical
point of view, terrestrial photogrammetry was the first powerful
tool in obtaining reliable metric information about glaciers in
mountainous landscapes. Today, however, terrestrial photogrammetry
is only applied occasionally in glacier studies, if at all.
In this paper we seek to show that the availability of low-cost
high resolution digital (consumer) cameras opens up new
perspectives in glacier monitoring. Since digital photogrammetric
software is readily available for 3D data capture, we conclude
that there is a good chance of a revival of classical terrestrial
photogrammetry in the digital domain.
The potential of a fully digital approach using a low-cost digital
consumer camera has been investigated in a case study. The main
task of the study was to obtain parameters quantifying the retreat
of the Goessnitzkees glacier from ground-based photographs taken
at three different time periods (1988, 1997, 2003).
Key words: Goessnitzkees, glacier mapping and monitoring, digital
photogrammetry, terrestrial photogrammetry, Zeiss TAL
phototheodolite, Rolleiflex 6006 réseau camera, Nikon D100 digital
camera.
Paper presented at the 4th ICA Mountain cartography Workshop, 30
September - 2 October 2004, Vall de Nuria, Catalonia, Spain.
Viktor Kaufmann & Richard Ladstädter
Institute of Remote Sensing and Photogrammetry
Graz University of Technology
Steyrergasse 30, A-8010 Graz, Austria
Tel.: +43 316 873-6336, Fax: +43 316 873-6337
e-mail: viktor.kaufmann@tugraz.at
Abstract
Rock glaciers are striking phenomena of high mountain permafrost.
These periglacial landforms are composed of rock and ice and creep
downslope at a typical rate of a few decimeters per year. This
movement and other surface changes can be measured by various
observation techniques. In this paper a digital-photogrammetric
approach to rock glacier monitoring is described based on
multi-temporal aerial photographs. A software package, ADVM
(Automatic Displacement Vector Measurement), has been developed,
which automatically derives 3D displacement vectors from the
photographs. The basic concepts of this software will be given
first, followed by a detailed description of a new constrained
image matching technique, implemented in the current ADVM 2.0
version. Finally, the successful application of the software is
shown in a case study: The spatio-temporal evolution and dynamic
behavior of the Hinteres Langtalkar rock glacier (Hohe Tauern
range of the Austrian Alps) was reconstructed using aerial
photographs (1954-1999). Results of the practical investigations
are presented graphically and numerically.
Key words: Environment, Geomorphology, Change Detection,
Monitoring, Aerial, Multitemporal, Digital, Photogrammetry
Paper presented at the 20th Congress of the International Society
for Photogrammetry and Remote Sensing, 12-23 July 2004, Istanbul,
Turkey.
Lado W. Kenyi
Institute of Digital Image Processing
Joanneum Research, Graz, Austria
Wastiangasse 6, A-8010 Graz, Austria
e-mail: lado-wani.kenyi@joanneum.at
Abstract
The detection and quantification of surface deformation of an
active rock glacier using the differential synthetic aperture
radar (SAR) interferometry (D-InSAR) technique is presented. An
average deformation rate of -6 mm/35 days in the radar line of
sight was estimated for the summer of 1992. The maximum
deformation rate, -18 mm/35 days, was identified at the upper part
of the rock glacier, whereas the deformation rate at the snout of
the rock glacier was about -10 mm/35 days. The spatial
distribution of the surface deformation in the D-InSAR
displacement map is smooth and supports the idea that ice is the
stress-trasferring medium in rock glaciers.
Index terms: Differential synthetic aperture radar interferometry
(D-InSAR), mountain permafrost creep, rock glaciers, synthetic
aperture radar (SAR) interferometry.
IEEE Transactions on Geoscience and Remote Sensing, Vol. 1, No.
6, June 2003, 152-1515.
Lado W. Kenyi
Institute of Digital Image Processing
Joanneum Research, Graz, Austria
Wastiangasse 6, A-8010 Graz, Austria
e-mail: lado-wani.kenyi@joanneum.at
Abstract
The detection and quantification od surface deformation of an active rock glacier using the differential SAR interferometry technique is presented. Anaverage deformation rate of -6mm/35 days in the radar line-of-sight in the summer 1992 was estimated. The maximum deformation rate was located at the upper part of the rock glacier and amounts to -18mm/35 days. In contrast, at the snout of the rock glacier the deformation rate was onlöy arount -10mm/35 days. The spatial distribution of the surface deformation in the D-InSAR displacement map is smooth and support the idea that ice is the stress transferring medium in rock glaciers.
Paper presented at the 8th International Conference on
Permafrost, 21-25 July 2003, Zurich, Switzerland.
Viktor Kaufmann & Richard Ladstädter
Institute of Geodesy
Graz University of Technology
Steyrergasse 30, A-8010 Graz, Austria
Tel.: +43 316 873-6336, Fax: +43 316 873-6337
e-mail: viktor.kaufmann@tugraz.at
Abstract
This paper presents a special measuring method of surface deformation and flow velocity of creeping rock glaciers based on digital photogrammetry. The underlying concept of automatic measurement of 3-D surface displacement vectors in time-series of multi-year digital aerial photographs is explained. In contrast to photogrammetric standard procedures image matching is not carried out in the space of the original photos but in quasi-orthophotos derived therefrom using rough and preliminary digital terrain models. A software package called ADVM (Automatic Displacement Vector Measurement), which is written in Visual C++ for running on a Windows-based PC, has been developed. The software has been tested within the framework of two case studies which comprised the spatio-temporal analysis of the kinematic behavior of three active rock glaciers in the Austrian Alps, i.e. the adjacent Inneres and Aeusseres Hochebenkar rock glaciers in the Oetztal Alps and the Hinteres Langtalkar rock glacier located in the Schober group, Hohe Tauern range. Some selected results of the photogrammetric evaluation are presented numerically and graphically.
Paper presented at the 8th International Conference on
Permafrost, 21-25 July 2003, Zurich, Switzerland.
Andreas Kääb
Department of Geography
University of Zurich, Switzerland
Viktor Kaufmann & Richard Ladstädter
Institute of Geodesy
Graz University of Technology
Steyrergasse 30, A-8010 Graz, Austria
Tel.: +43 316 873-6336, Fax: +43 316 873-6337
e-mail: viktor.kaufmann@tugraz.at
T. Eiken
Department of Geography
University of Oslo, Norway
Abstract
Recent high-resolution measurements of surface velocity fields using terrestrial, air- and space-borne methods have deepened insight into dynamics of rock glaciers. Here, we compare selected studies on surface velocity fields in order to identify basic processes involved in the development of rock glacier surfaces. The evolution of rock glacier geometry is shown to be a function of mass advection, 3-dimensional straining, thaw settlement or frost heave, respectively. All of these processes can reach the same order of magnitude. Available studies revealed creep fields to be highly coherent in space, clearly pointing to the presence of stress-transfering ice in the ground. The magnitude and type of dynamic processes reflect a high thermally-induced inertia of the creeping mountain permafrost. Systematic globally distributed monitoring series are identified as a major requirement for future research.
Paper presented at the 8th International Conference on
Permafrost, 21-25 July 2003, Zurich, Switzerland.
Arnold Bauer and Gerhard Paar
Institute of Digital Image Processing
Joanneum Research, Graz, Austria
Wastiangasse 6, A-8010 Graz, Austria
e-mail: arnold.bauer@joanneum.at, gerhard.paar@joanneum.at
Viktor Kaufmann
Institute of Geodesy
Graz University of Technology
Steyrergasse 30, A-8010 Graz, Austria
Tel.: +43 316 873-6336, Fax: +43 316 873-6337
e-mail: viktor.kaufmann@tugraz.at
Abstract
The evaluation of glacier and rock glacier surface changes needs fast and cheap observation methods with an accuracy in the range of a few centimeters. Long-range laser scanners can achieve measuring distances up to a few kilometers of range. It is shown that a system using such a device is able to successfully perform an efficient long-term change survey. We report on the sensor and software setup, the logistics and the procedure for data evaluation to perform the proposed monitoring task. An experiment was carried out at the Hinteres Langtalkar rock glacier in the Hohe Tauern range of the Austrian Alps. The obtained results enable the access to high-resolution surface deformation data in all three dimensions. Relevant parameters and advantages of the system as well as drawbacks and ideas for further improvements are pointed out. The operational system is available for further scientific exploitation.
Paper presented at the 8th International Conference on
Permafrost, 21-25 July 2003, Zurich, Switzerland.
Viktor Kaufmann
Institute of Geodesy
Graz University of Technology
Steyrergasse 30, A-8010 Graz, Austria
Tel.: +43 316 873-6336, Fax: +43 316 873-6337
e-mail: viktor.kaufmann@tugraz.at
Abstract
This paper describes a project (2001 – 2002), which has been initiated and partially financed by the Oberpinzgau regional branch of the Austrian Forest Engineering Service of Torrent and Avalanche Control. The Institute of Geodesy of the Graz University of Technology was asked to provide basic information about the past 50 years of spatio-temporal development and the present state of the dynamic behavior of the very active Blaubach landslide.
Key words: Landslide monitoring, aerial photogrammetry, geodetic survey, change detection, deformation measurement, creep velocity, surface height change, visualization, computer animation.
Paper presented at the 7th International Symposium on High
Mountain Remote Sensing Cartography (HMRSC-VII), Bishkek, Kyrgyz
Republic, 15-26 July 2002.
Viktor Kaufmann and Richard Ladstädter
Institute of Geodesy
Graz University of Technology
Steyrergasse 30, A-8010 Graz, Austria
Tel.: +43 316 873-6336, Fax: +43 316 873-6337
e-mail: viktor.kaufmann@tugraz.at
Abstract
Rock glaciers are creep phenomena of alpine/mountain permafrost
and consist of a mixture of rocks (debris) and ice. The upper
layer (= active layer) is only composed of rocks, its voids are
not filled with ice. From a bird’s eye view rock glaciers display
a viscous flow-like landform with often prominent furrows and
ridges. Typically, the front slope of intact rock glaciers is
straight and steep. Rock glaciers may be lobate or tongue-shaped,
their age is estimated at several thousands of years.
Active rock glaciers are creeping downhill by force of gravity.
The annual flow velocities are in the range of centimeters to
meters. This movement causes surface deformation, creating a
topography as described above. In general, the rate of change of
the flow velocity and of the rock glacier thickness is strongly
influenced by climatic parameters, i.e., the mean annual air
temperature and precipitation. In the last two decades rock
glaciers have been studied intensively in order to support
theories on climatic change, and especially to give proof of
recent climatic warming.
In the first part of our poster presentation we introduce our
in-house developed software package ADVM (Automatic Displacement
Vector Measurement) with which surface flow velocities and surface
height change of rock glaciers can be measured semi-automatically
by means of digital photogrammetric methods applied to digitized
multi-temporal aerial photographs. In the second part results from
two case studies are presented numerically and graphically.
The concept of the ADVM software is based on the automatic
measurement of 3-D displacement/flow vectors of prominent features
of the rock glacier surface, i.e. rocks and boulders, in aerial
photographs taken in two different time periods. In order to cope
with differing photo scales and flight line geometries we propose
the use of quasi-orthophotos (cp. Baltsavias 1996 and Schenk et
al. 1990) for digital image matching. Preliminary disparity maps
between the orthophotos are computed using the normalized
cross-correlation function. Based on this information of
approximate locations of homologous points high-precision image
matching is then only carried out at points, which had been
selected using the Foerstner interest operator, applying the
least-squares matching algorithm. As a result, precise 3-D
displacement/flow vectors can be computed and the given
preliminary digital terrain model(s) can be improved as well.
The ADMV software has been tested within the framework of two case
studies which comprised the spatio-temporal analysis of the
dynamic behavior of three active rock glaciers in the Austrian
Alps, i.e., the Inneres and Aeusseres Hochebenkar rock glaciers in
the Oetztal Alps and the Hinteres Langtalkar rock glacier located
in the Schober group, Hohe Tauern range. Multi-year aerial
photographs taken in the years between 1953 and 1999 were
evaluated. From a geomorphological point of view the main findings
are as follows: The analysis of the digital measurements obtained
for the Aeusseres Hochebenkar rock glacier and the Hinteres
Langtalkar rock glacier reveal a surface flow velocity field which
increases nearly linearly from the root to the snout of the rock
glaciers, with maximum values of 1-2 m/year. The quite active
state of the two rock glaciers is mainly induced by their specific
topographic situation. At the Inneres Hochebenkar rock glacier two
active regions (present maximum horizontal flow velocities of up
to 35 cm/year) are separated from each other by a rather inactive
zone.
Paper to be presented at the ISPRS Commission III, Symposium
2002, Graz, Austria, 9-13 September 2002..
Endbericht zum Projekt des Forsttechnischen Dienstes für Wildbach- und Lawinenverbauung, Gebietsbauleitung Oberpinzgau - Kurzfassung
Viktor Kaufmann (Projektleiter)
Institut für Geodäsie
Technische Universität Graz
Steyrergasse 30, A-8010 Graz
Tel.: +43 316 873-6336, Fax: +43 316 873-6337
E-mail: viktor.kaufmann@tugraz.at
Zusammenfassung
Hauptziel dieses Projektes war die quantitative Erfassung der Massenbewegung eines Rutschhanges im Talschluss des Blaubachgrabens, Gemeinde Krimml, Salzburg. Das Arbeitsgebiet (geographische Position 12°08’E, 47°13’N; ÖK 1:50.000, Blatt Krimml, Nr. 151 bzw. Alpenvereinskarte Zillertaler Alpen, östl. Blatt, Nr. 35/3, 1:25.000) ist aufgrund seiner morphologischen, geologischen und hydrologischen Gegebenheiten einer ausgeprägten Morphodynamik unterworfen und stellt ein (bereits wohlbekanntes) Gefahrenpotenzial für die Umwelt dar. Als Grundlage für die Weiterführung von bereits eingeleiteten Bau- und Sicherungsmaßnahmen im Blaubachgraben und als Basis für noch zu planende Meliorationsarbeiten im Rutschhang waren digitale Geländemodelle, Orthophotos und insbesondere numerische Angaben zur Morphodynamik (räumliche Verteilung und Größe der Fließgeschwindigkeit, Höhenänderung der Geländeoberfläche, Volumenänderung) zu ermitteln. Bei der Lösung dieser ingenieur-technischen Aufgabenstellung kamen sowohl geodätische als auch photogrammetrische Methoden zur Anwendung. Es wurden im speziellen folgende Projektziele erreicht:
1. Um die aktuelle bzw. auch die zukünftige Bewegung des
Rutschhanges für ausgewählte Messpunkte mit hoher Genauigkeit
feststellen zu können, wurde ein geodätisches Beobachtungsnetz
(Stütznetz) eingerichtet. Für die Bestimmung der gesuchten
dreidimensionalen Verschiebungsvektoren wurde eine repräsentative
Anzahl von Messpunkten in der Rutschungszone ausgewählt und
dauerhaft stabilisiert. Durch geodätische Einmessung dieser
Beobachtungspunkte zu zwei Epochen im Sommer/Herbst 2001 ist das
aktuelle Ausmaß der Rutschung quantitativ erfasst worden. Die
Messergebnisse (= dreidimensionalen Verschiebungsvektoren) wurden
numerisch ausgewiesen und auch anschaulich graphisch dargestellt.
2. Für die raum-zeitliche Analyse des Rutschhanges wurde
eine repräsentative Anzahl von Luftbildern (1953-1999) ausgewählt,
angekauft und für die weitere photogrammetrische Auswertung
digital aufbereitet.
3. Für die Herstellung von Orthophotos und für die
zahlenmäßige Abschätzung des Massentransportes im Rutschungsgebiet
wurden hochauflösende digitale Geländemodelle (DGM) für drei
repräsentative Epochen (1953, 1989 und 1997) durch konventionelle
Luftbildauswertung am Analytischen Stereoauswertegerät bestimmt.
4. Für die visuelle Interpretation der Morphodynamik der
Rutschungszone wurden für alle Aufnahmezeitpunkte Orthophotos,
Quasi-Orthophotos bzw. projektiv umgebildete Luftbilder auf
digitalem Wege erstellt. Insbesondere wurde mit Hilfe der
Stereoskopie die raum-zeitliche Bewegung des Rutschungsgebietes
visuell leicht auffassbar gemacht (Ausnutzung des Effektes der
Bewegungsparallaxe).
5. Es wurden dreidimensionale Verschiebungsvektoren bzw.
daraus abgeleiteten Bewegungsgrößen (jährliche horizontale
Fließgeschwindigkeit) für ausgewählte Objektpunkte (Gebäude und
Bäume) innerhalb der Rutschungszone durch konventionelle
photogrammetrische Auswertung der Luftbildzeitreihe am
Analytischen Plotter bestimmt.
6. Es erfolgte eine raum-zeitliche Analyse des gesamten
Luftbildmaterials mit Hilfe von digitalphotogrammetrischen
Methoden. Für die auswertbaren Zeitintervalle zwischen 1953 und
1999 wurde die dreidimensionale Deformation der Rutschungszone
flächendeckend sowohl durch ein dichtes Vektorfeld als auch durch
die Angabe der Höhenänderung der Geländeoberfläche beschrieben.
Die Ergebnisse wurden wahlweise numerisch bzw. graphisch
dargestellt.
7. Aus dem Vergleich der durch die Digitalphotogrammetrie
ermittelten digitalen Geländemodelle zu den einzelnen Epochen
wurde eine zumindest grobe Abschätzung des Massenumsatzes im
gesamten Arbeitsgebiet vorgenommen..
8. Digitale Aufbereitung aller punktuellen und
flächenhaften Auswerteergebnisse in einem für die
Weiterverarbeitung in einem GIS günstigen Datenformat.
Viktor Kaufmann
Institut für Angewandte Geodäsie
Technische Universität Graz
Steyrergasse 30, A-8010 Graz
Tel.: +43 316 873-6336, Fax: +43 316 873-6337
E-mail: viktor.kaufmann@tugraz.at
Zusammenfassung
In diesem Beitrag soll erstmals eine Gesamtschau aller
Forschungsprojekte vorgenommen werden, welche das Institut für
Angewandte Geodäsie der TU Graz in Zusammenarbeit mit dem Institut
für Geographie der UNI Graz und dem Institut für Digitale
Bildverarbeitung von Joanneum Research Graz im Nationalpark Hohe
Tauern im Zeitraum 1995-2000 durchgeführt hat. Gegenstand der
wissenschaftlich-technischen Projekte sind einerseits die beiden
benachbarten Gletscher Gößnitz- und das Hornkees in der
Schobergruppe und die davon unweit gelegenen Blockgletscher im
Weißenkar und beim Hinteren Langtalsee und andererseits der
Dösener Blockgletscher in der Ankogelgruppe.
Gletscher und Blockgletscher sind markante Landschaftselemente des
Hochgebirgsraumes und unterliegen einem fortwährenden
Veränderungsprozess in Abhängigkeit der auf sie wirkenden
physikalischen Kräfte und meteorologischen Bedingungen. Dieser
Prozess ist bei Gletschern in Form von Fließbewegung, Vorstoß bzw.
Rückzug meist deutlich sichtbar ausgeprägt, wohingegen das
langsame Kriechen bzw. eine Volumenänderung von Blockgletschern
nahezu von unseren Augen unbemerkt erfolgt.
Ziel der Projekte ist es, die dynamische Veränderung der erwähnten
"Gletscher" in Funktion von Raum und Zeit quantitativ zu
beschreiben. Begleitende Untersuchungen wurden durchgeführt, um
das Methodenspektrum zur Lösung der Aufgabenstellung nach
Kriterien, wie z.B. Genauigkeit und Kosten, zu bewerten und in
Hinblick auf zu planende Langzeit-Beobachtungsprogramme – im
Rahmen der Programme zur Erfassung der Auswirkungen der globalen
Klimaveränderung – weiterzuentwickeln.
Schlagwörter: Gletscher-Monitoring, Blockgletscher-Monitoring, geodätische Vermessung, Photogrammetrie, Fernerkundung, Kartographie, Computeranimation.
Schriftlicher Beitrag zum 2. Symposium zur Forschung im
Nationalpark Hohe Tauern, 15. - 17. November 2001, Burg Kaprun,
Salzburg, Österreich.
Lado W. Kenyi
Institute of Digital Image Processing
Joanneum Research
Wastiangasse 6, A-8010 Graz, Austria
Tel.: +43 316 876-1715
Fax: +43 316 876-1720
e-mail: lado-wani.kenyi@joanneum.ac.at
Viktor Kaufmann
Institute of Applied Geodesy
Graz University of Technology
Steyrergasse 30, A-8010 Graz, Austria
Tel.: +43 316 873-6336, Fax: +43 316 873-6337
e-mail: viktor.kaufmann@tugraz.at
Abstract
The detection of active rock glacier and the quantification of the observed surface movement as well as its temporal change using the D-InSAR method are presented. An average deformation rate of -7.7 mm/35 days in the radar line-of-sight, iin the summer of 1992, was estimated. Whereas, the corresponding geodetic measurement, vertical component of 3D flow velocity, was about -8.0 mm/35 days. Additionally, the spatial distribution of the rock glacier surface deformation derived from the D-InSAR data matches the photogrammetric and geodetic generated results to a very high degree.
Paper presented at the IGARSS 2001 International Geoscience and
Remote Sensing Symposium, University of New South Wales, Sydney,
Australia, 9-13 July 2001.
Viktor Kaufmann and Richard Ladstaedter
Institute of Applied Geodesy
Graz University of Technology
Steyrergasse 30, A-8010 Graz, Austria
Tel.: +43 316 873-6336, Fax: +43 316 873-6337
e-mail: viktor.kaufmann@tu-graz.ac.at
Abstract
The spatio-temporal variations of the surface of a rock glacier, i.e. the change of elevation and the three-dimensional directional deformation, can be determined using various quantitative measurement methods, i.e., geodetic survey, satellite-based positioning with GPS/GLONASS, photogrammetry, radar interferometry, and also laser scanning. In this paper we introduce a new concept of mapping and monitoring of rock glaciers by means of digital (softcopy) photogrammetry. Digital photogrammetry is based on digital image data and computer processing. Image matching, i.e. digital point transfer, is used as a powerful tool for automatic measurement of homologous, i.e. conjugate, points in the digital data sets. This technique enables a semi-automatic or even automatic triangulation of digital photographs, the automatic computation of digital terrain models, and subsequently, the automatic measurement of a dense field of three-dimensional flow vectors based on multi-year image data, in particular. Various aspects of the proposed processing chain are discussed in detail. The present concept has been implemented in a software package called ADVM (Automatic Displacement Vector Measurement), which is written in Visual C++ for running on a Windows-based personal computer. A case study has been carried out in the Oetztal Alps, Austria, in order to demonstrate the applicability of the concept. Aerial photographs (1953, 1969, 1971, 1977, 1979, 1981, 1990, and 1997) covering two adjacent rock glaciers, i.e. the Outer and the Inner Hochebenkar rock glacier, were acquired from the Austrian Federal Office of Metrology and Surveying. The various steps of the evaluation process, i.e., scanning of the analogue photographs, photogrammetric orientation, orthophoto production, computation of digital terrain models, and the determination of three-dimensional flow vectors, are described. Examples of the results obtained are presented numerically and graphically. For the first time it has been possible to reveal the dynamic behaviour of the Hochebenkar rock glaciers with high spatial resolution and with full coverage of the area of interest. The ease of the proposed method was confirmed, and moreover, the overall accuracy is high and the processing time of the given multi-year data set is promisingly low. The paper concludes with recommendations for further developments and improvements.
Paper presented at the 6th International Symposium on High
Mountain Remote Sensing Cartography (HMRSC-VI), Addis Ababa,
Ethiopia, 4-5 September 2000.
Lado W. Kenyi
Institute of Digital Image Processing
Joanneum Research
Wastiangasse 6, A-8010 Graz, Austria
Tel.: +43 316 876-1715
Fax: +43 316 876-1720
e-mail: lado-wani.kenyi@joanneum.ac.at
Viktor Kaufmann
Institute of Applied Geodesy
Graz University of Technology
Steyrergasse 30, A-8010 Graz, Austria
Tel.: +43 316 873-6336, Fax: +43 316 873-6337
e-mail: viktor.kaufmann@tu-graz.ac.at
Abstract
Synthetic Aperture Radar (SAR) systems normally record both the amplitude and the phase of the backscattered echoes. However, the phase of a single backscattered image is of no use and therefore, conventionally the amplitude or intensity image is usually provided to the user. But on the contrary, the phase difference of two backscattered SAR images of the same area on the ground taken at slightly different view angles can be utilised to generate digital elevation model (DEM) of the imaged terrain. This technique is known as SAR interferometry (InSAR) and can be extended to differential SAR interferometry (D-InSAR) to detect surface changes in the order of few cm. Although the D-InSAR has been shown to successfully derive surface displacement in the radar line-of-sight caused by earthquakes or mass movements in alpine and arctic terrain, a number of questions related to the properties of rock glaciers and the imaging geometry of the SAR sensor remain to be answered. These include the relative small size of the rock glaciers in comparison to the SAR pixel resolution, the rough surface topography composed of debris and rocks, the perennial snow patches and snow cover most of the year in the areas of interest, the rather small flow velocities of active rock glaciers in the range of centimetres to few meters (in some cases) per year, the look angle of the SAR sensor, and the geometric and temporal baselines requirements for successful D-InSAR data sets.
In this paper, the detection of active, i.e. creeping rock glaciers and consequently the quantification of the observed surface deformation, its temporal change using D-InSAR methods and the prerequisites to perform such analysis on a regional scale is presented. In one of the study cases, the active Doesen rock glacier, where the coherency of interferometric pairs was very high and the perpendicular component of the baselines were almost zero, an average deformation rate of about -0.77 cm/35 days (summer 1992) in the radar line-of-sight was estimated. In the following sections the description of the SAR data compiled, the interferometric processing procedures used to generate the D-InSAR products and the discussion and quantification of the results achieved are presented.
Paper presented at the ERS-ENVISAT Symposium, Gothenburg, Sweden,
16-20 October 2000.
Viktor Kaufmann
Institute of Applied Geodesy
Graz University of Technology
Steyrergasse 30, A-8010 Graz, Austria
Tel.: +43 316 873-6336, Fax: +43 316 873-6337
e-mail: viktor.kaufmann@tu-graz.ac.at
Reinhard Ploesch
Computing and Information Services Center
Graz University of Technology
Steyrergasse 30, A-8010 Graz, Austria
Tel.: +43 316 873-7192/5930, Fax: +43 316 873-7699
e-mail: ploesch@zid.tu-graz.ac.at
Abstract
This paper describes the reconstruction and visualization of the
retreat of two small cirque glaciers since the Little Ice Age
advance of 1850. The two neighboring glaciers, Goessnitzkees and
Hornkees, are located in the Schober group (Hohe Tauern range,
Austria). The detailed explanations refer to a research project
which has been carried out by the Institute of Geography
(University of Graz) and the Institute of Applied Geodesy (Graz
University of Technology) with financial assistance from the Hohe
Tauern National Park Service. On the basis of prominent moraines
(1850), old maps (1873, 1929) and metric aerial photographs (1954,
1969, 1974, 1983, 1992, and 1997) 9 glacial stages of the recent
history of the glacier were reconstructed. All relevant data are
stored in a digital database (for glacier studies) which is
composed of 4 layers, i.e., digital terrain model, glacier
boundaries/masks, orthophotos, and collateral information. A
comprehensive spatial-temporal analysis of the given time series
was performed using the digital database. The evaluation reveals,
e.g., that the surface areas of Goessnitzkees and Hornkees have
decreased by 51% and 61%, respectively, since 1850. The
corresponding reduction in volume amounts to 77.5 mill. m³ and
38.2 mill. m³. Furthermore, the digital database is also the data
source for subsequent cartographic work, i.e. the visualization of
glacier retreat. The presented examples of visualization cover
traditional maps, e.g., orthophoto maps, contour line maps and
thematic maps, and also modern techniques of computer animation.
The latter has been implemented in a "glacier movie" which
presents the glacial retreat as a continuous process over space
and time.
Zusammenfassung
In diesem Beitrag wird die Rekonstruktion und Visualisierung des Gletscherrückganges von zwei Kargletschern (Gößnitz- und Hornkees) der Schobergruppe (Hohe Tauern, Österreich) seit dem neuzeitlichen Hochstand von 1850 erörtert. Die Ausführungen beziehen sich auf ein Forschungsprojekt, welches gemeinsam vom Institut für Angewandte Geographie der Universität Graz und vom Institut für Angewandte Geodäsie der Technischen Universität Graz ausgeführt und vom Kärntner Nationalparkfonds finanziell unterstützt wurde. Die Rekonstruktion des Gletscherhochstandes von 1850 erfolgte anhand von Ufermoränen. Alte Karten wurden zur Rekonstruktion der Stände von 1873 und 1929 herangezogen, wohingegen Luftbilder für die jüngeren Stände (1954, 1969, 1974, 1983, 1992 und 1997) photogrammetrisch ausgewertet wurden. Die Rekonstruktionsergebnisse der einzelnen Gletscherstände wurden in einer digitalen Datenbasis, welche (1) digitale Geländemodelle, (2) Gletschergrenzen bzw. –flächen, (3) Orthophotos und (4) Zusatzinformationen umfaßt, für weiterführende glaziologische und kartographische Arbeiten bereitgestellt. Die numerische Auswertung ergab u.a., daß das Gößnitzkees 51% und das Hornkees 61% seiner Fläche seit 1850 verloren hat. Die entsprechenden Volumenverluste sind 77,5 Mill. m³ bzw. 38,2 Mill. m³. Die Visualisierung der einzelnen Gletscherstände sowie des Gletscherrückganges umspannt die breite Palette der kartographischen Darstellungsmöglichkeiten (Orthophotokarte, Schichtlinienplan, Axonometrie, thematische Karte) bis hin zur Computer-Animation, wo der Gletscherrückgang als kontinuierlicher Prozeß synthetisiert wurde. Zum gestellten Thema liegt ein Videofilm vor.
Paper presented at the International ICA Workshop on "High
Mountain cartography 2000", Alpine Centre Rudolfshütte, Salzburg,
29 March - 2 April 2000.
Viktor Kaufmann
Institute of Applied Geodesy
Graz University of Technology
Steyrergasse 30, A-8010 Graz, Austria
Tel.: +43 316 873-6336, Fax: +43 316 873-6337
e-mail: viktor.kaufmann@tu-graz.ac.at
Reinhard Ploesch
Computing and Information Services Center
Graz University of Technology
Steyrergasse 30, A-8010 Graz, Austria
Tel.: +43 316 873-7192/5930, Fax: +43 316 873-7699
e-mail: ploesch@zid.tu-graz.ac.at
Abstract
This paper describes the three-dimensional reconstruction of the glaciation of two neighboring cirques from the Little Ice Age advance of 1850 up to the present (1997), and the visualization of its spatio-temporal changes during this time period by means of standard methods of cartography and modern computer animation. The glaciers (Goessnitzkees and Hornkees) are located in the Schober group (Hohe Tauern range, Central Alps, Austria). A total of 9 different glacial stages were reconstructed. Computer-based analysis of the given time series was performed using a special digital database for glacier studies. Various numerical and graphical results show the course of deglaciation. Since the glaciers are largely covered by debris, a digital-photogrammetric procedure based on the Least Squares Matching (LSM) algorithm was developed in order to automate the generation of digital terrain models and the computation of three-dimensional flow vectors from the multi-year aerial photographs. This procedure facilitates the combination of aerial photographs of any scale and geometry. Practical results prove the applicability of this method in glacier mapping. The computer animation "glacier movie" (with sound) of the glacier retreat has been implemented in the PC-based information system of the Austrian Hohe Tauern National Park for public access.
Paper will be presented at the 19th ISPRS Congress, Amsterdam,
The Netherlands, 16-23 July, 2000.
Viktor Kaufmann
Institute of Applied Geodesy
Graz University of Technology
Steyrergasse 30, A-8010 Graz, Austria
Tel.: +43 316 873-6336, Fax: +43 316 873-6337
e-mail: viktor.kaufmann@tu-graz.ac.at
Reinhard Ploesch
Computing and Information Services Center
Graz University of Technology
Steyrergasse 30, A-8010 Graz, Austria
Tel.: +43 316 873-7192/5930, Fax: +43 316 873-7699
e-mail: ploesch@zid.tu-graz.ac.at
Abstract
This paper describes the reconstruction and visualization of the retreat of two small cirque glaciers since the Little Ice Age advance of 1850. The two neighboring glaciers, Goessnitzkees and Hornkees, are located in the Schober group (Hohe Tauern range, Austria). The detailed explanations refer to a research project which has been carried out by the Institute of Geography (University of Graz) and the Institute of Applied Geodesy (Graz University of Technology) with financial assistance from the Hohe Tauern National Park Service. On the basis of prominent moraines (1850), old maps (1873, 1929) and metric aerial photographs (1954, 1969, 1974, 1983, 1992, and 1997) 9 glacial stages of the recent history of the glacier were reconstructed. All relevant data are stored in a digital database (for glacier studies) which is composed of 4 layers, i.e., digital terrain model, glacier boundaries/ masks, orthophotos, and collateral information. A comprehensive spatial-temporal analysis of the given time series was performed using the digital database. The evaluation reveals, e.g., that the surface areas of Goessnitzkees and Hornkees have decreased by 51% and 61%, respectively, since 1850. The corresponding reduction in volume amounts to 77.5 mill. m³ and 38.2 mill. m³. Furthermore, the digital database is also the data source for subsequent cartographic work, i.e. the visualization of glacier retreat. The presented examples of visualization cover traditional maps, e.g., orthophoto maps, contour line maps and thematic maps, and also modern techniques of computer animation. The latter has been implemented in a "glacier movie" (with sound) which presents the glacier retreat as a continuous process over space and time.
Viktor Kaufmann
Institute of Applied Geodesy
Graz University of Technology
Steyrergasse 30, A-8010 Graz, Austria
Tel.: +43 316 873-6336, Fax: +43 316 873-6337
e-mail: viktor.kaufmann@tu-graz.ac.at
Abstract
The area of interest is located at the border between Chile and
Argentina at 27°10' S. latitude and 68°30' W. longitude in the
High Cordillera of the Andes and includes the second-highest
mountain of America, the Nevado Ojos del Salado. Although the
official Chilean altitude is given as 6,880 m, other figures can
be found in the literature and various other maps. Situated in a
picturesque volcanic terrain rising above the Puna de Atacama,
Nevado Ojos del Salado is not only interesting from a
geomorphological point of view, it is, e.g., the world´s highest
volcano, but also has recently become a much-favored destination
of the mountaineering world.
Unfortunately, this area is not covered by reliable and
publicly available maps at scales larger than 1:250,000.
Therefore, this paper describes the methods employed in and
results obtained from topographic mapping of this remote area
using spaceborne as well as airborne remotely sensed data.
Exploiting Space Shuttle Earth-viewing photographs, ERS-1
Synthetic Aperture Radar images, and aerial photographs, it was
intended to derive orthophotos, digital elevation models,
topographic/geomorphological base maps, including various
derivatives, such as anaglyphs, stereograms, and axonometric
views, respectively, at a minimum of costs.
In order to get a general overview, i.e. to generate a base
map of the area, stereoscopic hand-held photographs from NASA's
SSEOP database were used. Parallax-free stereo vision was achieved
by means of an analytical plotter. Ground control points were
taken from the existing Chilean maps at scales 1:250,000 and
1:500,000 in order to georeference the image content. A digital
orthophoto and a topographic base map at 1:400,000 are presented.
Furthermore, two overlapping same-side ERS-1 SAR images from
adjacent descending orbits were acquired and provided in digital
format by the European Space Agency. In a first step, the image
data was radiometrically enhanced, and proper radar stereograms
were generated for image interpretation purposes. This is followed
by a brief discussion of recently developed mapping methods for
radar images.
In order to facilitate large-scale mapping a strip of panchromatic
aerial photographs at 1:30,000 scale, provided by the Instituto
Geografico Militar de Chile, was photogrammetrically oriented
using ground control points measured in one of the Shuttle
stereopairs at 1:840,000 scale. As a result, a topographic map at
1:15,000 scale and a high-resolution digital elevation model of
the central part of the Nevado Ojos del Salado were generated. The
photographs, given as analog paper prints, were scanned and
thereafter digitally rectified and mosaicked to form an orthophoto
of the volcano Ojos del Salado. A stereomate of this orthophoto
was produced as well. The scope of this work also includes various
combined image-line maps.
The presented cartographic products, available either in analog or
in digital format, for the first time allow detailed
geomorphological mapping of the Nevado Ojos del Saldo and its
surroundings and provide a far better means of orientation for
mountaineers in this very remote and deserted area in the Andes.
Keywords: Nevado Ojos del Salado, the Andes, topographic mapping,
digital orthophoto and stereomate, geomorphology, NASA SSEOP, and
ERS-1 Synthetic Aperture Radar.
Paper presented at the 3rd International Symposium on High-Mountain Remote Sensing Cartography, November 7 - 12, 1994, Mendoza, Argentina.
Viktor Kaufmann
Institute of Applied Geodesy
Graz University of Technology
Steyrergasse 30, A-8010 Graz, Austria
Tel.: +43 316 873-6336, Fax: +43 316 873-6337
e-mail: viktor.kaufmann@tu-graz.ac.at
Gerhard Karl Lieb
Institute of GeographyUniversity of Graz
Heinrichstraße 36, A-8010 Graz, Austria
Tel.: +43 316 380-5146, Fax: +43 316 380-9886
Abstract
The aim of the study is to show the variations in area, altitude
and volume of two neighbouring glaciers since the Little Ice Age
advance. The respective glaciers are situated in the Schober group
(Hohe Tauern range, Central Alps) between 2500 and 3100 m a.s.l.
The reconstruction of the maximum extent in 1850 was possible due
to well-preserved moraines, while the other stages were derived
from old maps (1872/73, 1928/29) and aerial photographs (1954,
1969, 1974, 1983, 1992 and 1997).
As a result digital maps and high-resolution digital terrain
models of all these glacial stages were obtained and numerically
evaluated in respect to glacier-characteristic parameters and
other hypsographical values.
Furthermore, an orthophoto map at 1:10,000 scale was produced in
order to show the present glaciation of 1997.
Summarizing the results it can be said that the two glaciers have
lost 51.5 % (Goessnitzkees) and 60.6 % (Hornkees) of their area
since 1850, the decrease in volume was 77.5 x 106 m³ and 38.2 x
106 m³, respectively. These values as well as some other data on
changes in area and volume according to elevational intervals
correspond quite well with results from other glaciers of the
Central Alps.
Keywords: Glacier changes, Austrian Alps, photogrammetry and high
mountain cartography.
Paper presented at the 5th International Symposium on High
Mountain Remote Sensing Cartography,
August 24 - 25, 1998, Arcata, California, U.S.A.
DEFORMATION ANALYSIS OF THE DOESEN ROCK GLACIER (AUSTRIA)
Viktor Kaufmann
Institute of Applied Geodesy
Graz University of Technology
Steyrergasse 30, A-8010 Graz, Austria
Tel.: +43 316 873-6336, Fax: +43 316 873-6337
e-mail: viktor.kaufmann@tu-graz.ac.at
Abstract
In the framework of a multidisciplinary research project on
high-mountain permafrost in the Austrian Alps a comprehensive
deformation analysis of the active Doesen rock glacier (Hohe
Tauern range) has been carried out using various geodetic and
photogrammetric methods. In 1995 a monitoring program was
established in order to obtain geomorphometric parameters of the
Doesen rock glacier for the past, present and future. Precise
geodetic measurements within an observation network are acquired
on a regular basis applying classical and also navigation
satellite-based methods. Aerial photographs (1954, 1969, 1975,
1983 and 1993) were photogrammetrically evaluated. The flow
vectors reveal that the horizontal velocity observed in the center
of the rock glacier has decreased from 29 cm/yr (1954-1975) to 17
cm/yr (1975-1993), whereas recent measurements (1995-1996)
indicate a significant increase in flow velocity (29 cm/yr).
Furthermore, this analysis also includes an evaluation of
volumetric changes of the Doesen rock glacier.
Paper presented at the 7th International Conference on Permafrost, 23 - 27 June 1998, Yellowknife, NWT, Canada.
Gössnitz- und Hornkees. Die Entwicklung zweier Kargletscher der Schobergruppe (Nationalpark Hohe Tauern, Kärnten) seit dem Hochstand von 1850
Endbericht zum Forschungsprojekt des Kärntner Nationalparkfonds - Kurzfassung
Ao.Univ.Prof. Mag. Dr. Gerhard Karl Lieb (Projektleiter)
Institut für Geographie
Universität Graz
Heinrichstraße 36
A-8010 Graz
Tel.: +43 316 380-5146
Fax: + 43 316 380-9886
e-mail: gerhard.lieb@kfunigraz.ac.at
1. Kurzpräsentation des Projektes
Dieses Projekt wurde in den Jahren 1996 bis 1998 unter meiner Leitung am Institut für Geographie der Universität Graz und am Institut für Angewandte Geodäsie, Abteilung für Photogrammetrie und Fernerkundung, der Technischen Universität Graz (Koordination: Viktor KAUFMANN) durchgeführt. Es war damit als interdisziplinäres Vorhaben konzipiert und zielte auf eine möglichst exakte und detaillierte Rekonstruktion der Entwicklung der beiden gegenständlichen Gletscher ab. In einem ersten Schritt wurde die topographische Situation im hinteren Gössnitztal durch eine Orthophotokarte (Luftbildkarte Gössnitz- und Hornkees 1:10.000) dokumentiert, die von V. KAUFMANN 1998 auf der Basis von Luftbildern des Jahres 1997 hergestellt wurde. Der nächste Schritt umfasste die Rekonstruktion von 8 weiteren Gletscherständen aus Geländebefunden (1850), historischen Karten (1873, 1929) und Luftbildern (1954, 1969, 1974, 1983, 1992) und die computergestützte Weiterbearbeitung des daraus gewonnenen Datensatzes in Hinblick auf die zeitliche Änderung der Größenparameter der Gletscher, insbesondere der Flächen und der Volumina. Schließlich wurden auch noch die Ergebnisse der seit 1982 alljährlich durchgeführten Gletschermessungen einbezogen und die landschaftlichen Veränderungen im Bereich der zurück weichenden Gletscherränder und ihrer Umgebung analysiert.
Das Projekt steht hierdurch in Zusammenhang mit der klimabezogenen Umweltforschung im Hochgebirge und bietet am Beispiel zweier kleiner Gletscher exakte Informationen über den Gletscherschwund seit der Mitte des 19.Jahrhunderts, dem letzten bedeutenden Hochstand der Alpengletscher. Durch die Klimaänderung, namentlich auf Grund einer signifikanten Erwärmung um im Mittel etwa 1°C, haben sich die Gletscher seit damals bedeutend verkleinert, was sich auch in markanten Veränderungen des Landschaftsbildes und der Umweltdynamik des Hochgebirgsraumes niederschlägt. Zu dessen Beurteilung und Quantifizierung wird durch die Projektergebnisse eine Fülle an Daten zur Verfügung gestellt. Darüber hinaus wurde auf technischer Seite ein umfangreicher Methodenvorrat zur effizienteren Analyse der raum-zeitlichen Veränderung von Gletschern (und anderen dynamischen Elementen der Hochgebirgsnatur, z.B. Blockgletschern) mit konsequent digitaler Ausführung aller Arbeitsschritte geschaffen.
2. Die wichtigsten Kenndaten der Gletscher im Überblick
Die folgende Übersichtstabelle zeigt eine Auswahl wichtiger Größenangaben zu den beiden untersuchten Gletschern in ihrem zeitlichen Wandel. Die Flächenangaben sind dabei Gesamtflächen des jeweiligen Gletschers, ihre Abnahme von Termin zu Termin zeichnet ein klares Bild vom Gletscherschwund seit der Mitte des 19.Jahrhunderts: 1997 bedeckte das Gössnitzkees nur noch 48,5 % und das Hornkees 39,4 % seiner Fläche von 1850. Auch die Höhenlage der Gletscherstirn, das ist der jeweils tiefste Punkt des Gletschers, illustriert den Rückgang der Vergletscherung dadurch, dass die Gletscherstirnen in zunehmend größeren Höhen zu liegen kamen und somit ein – im Falle des Hornkeeses fast 200 m umfassendes – Höhenstockwerk eisfrei wurde. Bei den Volumenangaben schließlich können nur Eisverluste zwischen den einzelnen Terminen, nicht jedoch die jeweiligen Gesamtvolumina angegeben werden, weil die gegenwärtigen Eismächtigkeiten nicht bekannt sind (diese könnten sich über noch nicht durchgeführte geophysikalische Messungen feststellen lassen). Umgerechnet in Wasserwert beträgt der gesamte Volumenverlust der beiden Gletscher im Zeitraum von 1850 bis 1997 104,1 Millionen m3, womit beispielsweise der Ossiachersee (Kärnten) etwa zur Hälfte gefüllt werden könnte.
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(1983/97) |
3. Grundzüge des Vergletscherungsganges
Um die Mitte des 19.Jahrhunderts hatten Gössnitz- und Hornkees wie fast alle anderen Gletscher der Alpen zum letzten Mal jene Maximalausdehnung, die sie im Laufe der Nacheiszeit (Postglazial oder Holozän) rund zehn Mal erreichten. Wie die im Projekt erhobenen Daten zeigen, setzte der Gletscherrückgang recht rasch ein, so dass beim nächsten dokumentierten Gletscherstand 1873 das Gössnitzkees nur mehr 93,9 % und das Hornkees 92,1 % seiner Fläche von 1850 besaßen. Bedauerlicherweise ist das Zeitintervall zum nächst folgenden rekonstruierbaren Stand 1929 mit 56 Jahren außerordentlich lange. Die mittleren jährlichen Flächen- und Volumenverluste sind jedoch an beiden Gletschern deutlich geringer als in den Perioden davor und danach und lassen somit erahnen, dass innerhalb der Zeitspanne 1873-1929 auch eine Vorstoßphase mit dem Höhepunkt um etwa 1920 eingelagert war. Leider ließ sich diese aus nur vereinzelten Moränenstücken nicht hinreichend genau rekonstruieren, weshalb an den beiden Gletschern keine quantitativen Angaben zu dieser alpenweit nachgewiesenen Vorstoßperiode gemacht werden können (obwohl kein Zweifel besteht, dass ssie auch die beiden gegenständlichen Gletscher erfasste).
Der Zeitraum 1929-1954 brachte an beiden Gletschern den bisherigen Höhepunkt des Gletscherschwundes. Das Gössnitzkees verlor in dieser Periode im Mittel eine Fläche von 1,40 ha und ein Volumen von 1,23 Millionen m3 jährlich, für das Hornkees lauten dieselben Werte 1,06 ha und 0,50 Millionen m3. Diese Angaben stehen in guter Übereinstimmung mit dem alpenweit beobachtbaren sehr gletscherabträglichen Witterungscharakter der Jahre um die Mitte des 20.Jahrhunderts.
Bereits in der folgenden Periode 1954-1969 erscheint der Gletscherrückgang deutlich gebremst, was mit den Beginn der Vorstoßperiode „von 1965 bis 1980" in Zusammenhang steht. Diese ist durch die 3 Stände 1969, 1974 und 1983 recht gut dokumentiert, erweist sich in ihren Auswirkungen an den beiden untersuchten Gletschern aber als außerordentlich schwach. Allein zwischen 1974 und 1983 wird durch leicht positive Volumenänderungen (die im Falle des Gössnitzkeeses ebenso wie die dort zu beobachtende geringfügige Flächenvergrößerung statistisch gar nicht signifikant sind) stationäres Gletscherverhalten angedeutet. Mit den jährlichen Gletschermessungen konnte am Hornkees von 1983 auf 1984 auch noch ein ganz schwacher Gletschervorstoß nachgewiesen werden, der an diesem Gletscher auch einen etwa 1-2 m mächtigen Moränenwall hinterließ (ohne dass der Gletscher hierdurch aber den Stand des Jahres 1974 wieder erreicht hätte). Die genannte Vorstoßperiode verdient an Gössnitz- und Hornkees diese Bezeichnung also nicht wirklich, war aber doch unverkennbar ein Zeitraum verzögerten oder zwischenzeitlich fehlenden Gletscherrückganges.
Seit den frühen 80er-Jahren des 20. Jahrhunderts hat sich der Gletscherrückgang als Folge einer fast ununterbrochenen Serie warmer Jahre mit meist niederschlagsarmen Wintern und nur seltenen sommerlichen Kaltlufteinbrüchen wieder stark intensiviert. Dies wird beispielsweise durch den hohen jährlichen Volumenverlust von 0,98 Millionen m3 am Gössnitzkees zwischen 1983 und 1992 (Mittel 1850-1997: 0,53 Millionen m3) verdeutlicht. Der Rückgang wird seit 1982 auch durch die jährlichen Gletschermessungen (im Rahmen des Gletscher-Messdienstes des Österreichischen Alpenvereins) in hoher zeitlicher Trennschärfe dokumentiert. Die Ergebnisse dieser Arbeiten können in laufend aktualisierter Form über das Internet auf der Homepage des Instituts für Geographie der Universität Graz unter http://www.kfunigraz.ac.at/geowww/klima/gletscher.html abgefragt werden. Alle Anzeichen, sowohl die Extrapolation der vorliegenden Daten als auch das Erscheinungsbild der Gletscher in der Landschaft, sprechen für ein Fortdauern des massiven Gletscherschwundes zumindest in den nächsten Jahren.
Im Projekt wurde auch die Entstehung eines neuen Sees durch den
Rückzug des Gössnitzkeeses bearbeitet. Hierbei handelt es sich um
ein markantes Beispiel für die landschaftlichen Veränderungen, die
sich auf Grund des Gletscherschwundes überall im Hochgebirge
einstellen. Der gegenständliche See („Eissee") etwa entwickelte
sich seit 1986 und hatte im September 1996 bereits eine Fläche
über 6000 m2 (siehe auch unter der oben angeführten
Internet-Adresse), wobei die maximalen Flächenzuwächse von jeweils
mehr als 1000 m2 von 1987 auf 1988 und von 1993 auf 1994 zu
verzeichnen waren. Diese Veränderungen im Landschaftsbild
verdienen ebenso wie die den Gletschern benachbarten und vom
Gletscherschwund betroffenen Phänomene (besonders Permafrost und
Erscheinungen der Hanginstabilität) in Zukunft verstärkte
Beachtung. Die hier vorgestellten Ergebnisse liefern in diesem
Sinne mit eine Grundlage für ein umfassendes Monitoring der im
Klimawandel begründeten Veränderungen in der hochalpinen Umwelt.
ENVIRONMENTAL STUDY ON A BADLAND AREA IN SOUTHERN ITALY
Viktor Kaufmann
Institute of Applied Geodesy
Graz University of Technology
Steyrergasse 30, A-8010 Graz, Austria
Tel.: +43 316 873-6336, Fax: +43 316 873-6337
e-mail: viktor.kaufmann@tu-graz.ac.at
Gerhard K. Lieb
Institute of Geography
University of Graz
Heinrichstrasse 36, A-8010 Graz, Austria
Tel.: +43 316 380-5146, Fax: +43 316 380-9886
e-mail: gerhard.lieb@kfunigraz.ac.at
Abstract
The Sant’ Arcangelo basin is part of the catchment area of the
Agri river and belongs to the Basilicata region in Southern Italy.
It consists of conglomerates, sands, and clays of Plio-Pleistocene
age. In this zone one of the most widespread badland area of
Europe has developed due to unfavourable natural conditions, such
as recent tectonic activity, and the semi-arid climate with
frequent events of heavy precipitation. Furthermore, the
degradation of vegetation and soil has been triggered by strong
human impact (excessive land utilisation). The region is a good
example of the high effectiveness of actual morphodynamics
directed by the climate. It also represents the natural problems
of this economically underdeveloped part of Italy ("Mezzogiorno").
In the framework of this study two thematic maps were produced and
printed, i.e. a Geomorphological Base Map and a Geomorphological
Study Map at scales of 1:50,000 and 1:10,000, respectively. The
1:50,000-scale map is an image map based on a high-resolution
space image acquired by a Russian KVR-1000 photographic system in
1990. This image is unique because due to the very low sun
elevation at the time of acquisition the characteristic badland
morphology, consisting of earth cones, is distinctly brought into
relief by the illumination of the sun. The second map shows a
subset of the first one superimposed with cartographic elements,
e.g. signatures for earth cones and piping gullies, derived from
large-scale aerial photographs dating from 1976. This paper
describes the environmental setting and also the changes thereof
observed in the study area derived from interpretation of both
satellite image maps, extensive field studies and analysis of
other collateral information.
Paper presented at the 16th EARSeL Symposium, Malta, 1996.
STEREO-RADARGRAMMETRIC
EVALUATION
OF ERS-1 SAR IMAGES:
A CASE STUDY IN SOUTHERN ITALY
V. Kaufmann (1), W. Mattner (1), J. Raggam (2), A. Almer (2), and J. Schnell (2)
(1) Institute of Applied Geodesy
Graz University of Technology
Steyrergasse 30, A-8010 Graz, Austria
Tel.: +43 316 873-6336, Fax: +43 316 873-6337
e-mail: viktor.kaufmann@tu-graz.ac.at
(2) Institute for Digital Image Processing
Joanneum Research Graz
Wastiangasse 6, A-8010 Graz, Austria
e-mail: joanneum@ac.at
Abstract
This paper describes two methods of unconventional mapping using
overlapping ERS-1 SAR Precision Images. The first method is a
hybrid one using classical ways of photogrammetric mapping based
on analog images which have been derived from radiometrically
enhanced digital SAR data. Whereas the second method was supposed
to semi-automatically derive 3-dimensional topographic information
by means of image correlation techniques. A case study was carried
out in the badlands of the Sant 'Arcangelo Basin in Southern Italy
in order to investigate the potential of ERS-1 SAR image
stereopairs, i.e., two overlapping same-side stereopairs from
ascending and descending orbits, for topographic/ geomorphometric
mapping, especially for obtaining a digital elevation model (DEM).
The critical points of the stereo mapping procedure for both
methods are highlighted. Furthermore, the overall quality of the
derived DEMs has been assessed using an existing high-resolution
DEM derived from airborne photographic data and an additional DEM
from a panchromatic SPOT-1 stereopair.
Keywords: ERS-1, SAR, radargrammetry, topographic mapping,
geomorphometric mapping, stereo image matching.
Paper presented at the 2nd ERS-1 Symposium on Space at the Service of our Environment, 11-14 October 1993, Hamburg, Germany.
SOME EXPERIMENTS ON RELIEF MAPPING FROM SPACE USING MICROWAVE AND OPTICAL IMAGEDATA: LOOKING AT THE BADLANDS IN SOUTHERN ITALY
V. Kaufmann and U. Fastner
Institute of Applied Geodesy
Graz University of Technology
Steyrergasse 30, A-8010 Graz, Austria
Tel.: +43 316 873-6336, Fax: +43 316 873-6337
e-mail: viktor.kaufmann@tu-graz.ac.at
Abstract
This paper describes the methods employed in and results obtained
from experiments on relief mapping using panchromatic SPOT-1,
ERS-1 SAR, and spectrozonal KFA-1000 stereopairs, as well as a
single high-resolution KVR-1000 image. The experiments have been
carried out in order to investigate the potential of the
above-mentioned spaceborne images for geomorphometric mapping. The
emphasis is on generating digital elevation models (DEMs) and
detecting relief changes.
In principle, two stereo mapping methods have been considered and
analyzed: a classical/hybrid method using analogue images with an
analytical plotter and a semi-automatic method using digital
images and image correlation techniques. Analogue images may be
either original ones or may be derived from radiometrically
enhanced digital image data exposed on film.
A badland prone area in the Basilicata region, Southern Italy, was
chosen as a study area to convey the practical work. As a
reference for accuracy analysis large-scale aerial photographs
were taken.
Paper presented at the EARSeL Workshop "Topography from Space" arragened in conjunction with the EARSeL 14th Symposium at Chalmers University of Technology, Göteborg, Sweden, 1994
DOCUMENTATION OF THE RETREAT OF GÖSSNITZKEES
AND HORNKEES GLACIERS (HOHE TAUERN RANGE, AUSTRIA) FOR THE TIME
PERIOD 1997-2006
BY MEANS OF AERIAL
PHOTOGRAMMETRY
V. Kaufmann and R. Ladstädter
Institute of Remote Sensing and Photogrammetry
Graz University of Technology
Steyrergasse 30, A-8010 Graz, Austria
Tel.: +43 316 873-6336, Fax: +43 316 873-6337
e-mail: viktor.kaufmann@tugraz.at
Abstract
Gössnitzkees and Hornkees are two small cirque glaciers (2006: 58.9 and 30.6 ha, respectively) located in the Schober group of the Hohe Tauern range of the Eastern Alps in Austria. The glacier history of both glaciers has already been documented for the time period 1850-1997 based on field evidence, historical maps and aerial photographs. The temporal change in area, surface height, and volume of both glaciers was presented numerically and graphically. In this paper we intend to extend the observation period to the present. Aerial photographs of 2002 and 2006 covering the area of interest were made available by the Tyrolean regional government and the Austrian Federal Office of Metrology and Surveying, Vienna. A digital photogrammetric workflow was applied to the image data provided. Based on these multi-temporal data we computed the volumetric and areal change of both glaciers along with the respective numerical values at elevational intervals of 50 m. The change in surface height and area of both glaciers is shown in thematic maps. The results include a new orthophoto map at 1:10,000 scale representing the glacial stage of 2006 and an estimation of the equilibrium line altitude.
Paper presented at the 6th ICA Mountain Cartography Workshop, 11-15 February 2008, Lenk, Switzerland.
MEASUREMENT OF SURFACE FLOW VELOCITY OF ACTIVE ROCK GLACIERS USING ORTHOPHOTOS OF VIRTUAL GLOBES
V. Kaufmann
Institute of Remote Sensing and Photogrammetry
Graz University of Technology
Steyrergasse 30, A-8010 Graz, Austria
Tel.: +43 316 873-6336, Fax: +43 316 873-6337
e-mail: viktor.kaufmann@tugraz.at
Abstract
In this paper we demonstrate how
multi-temporal high-resolution orthophotos taken from virtual
globes, such as Google Maps and Microsoft Bing Maps, can be
used not only for the detection of active rock glaciers but
also for the precise measurement of flow/creep velocities. Our
study area covers the central and western part of the
Keywords: Google Maps, Microsoft Virtual Earth, rock glacier, monitoring, flow/creep velocity, visualization, Hohe Tauern range, Austria.
Paper presented at the 7th ICA Mountain Cartography Workshop, 1-5 September 2010, Borsa, Romania.
Documentation and visualization of the morphodynamics of Hinteres Langtalkar rock glacier (Hohe Tauern range, Austrian Alps) based on aerial photographs (1954-2006) and geodetic measurements (1999-2007)
V. Kaufmann and R. Ladstädter
Institute of Remote Sensing and Photogrammetry
Graz University of Technology
Steyrergasse 30, A-8010 Graz, Austria
Tel.: +43 316 873-6336, Fax: +43 316 873-6337
e-mail: viktor.kaufmann@tugraz.at
Abstract
Hinteres Langtalkar rock glacier (46°59'N, 12°47'E) is located
in a glacially shaped cirque situated in the center of the
Schober group of the Hohe Tauern range, Austria. This
tongue-shaped creep phenomenon of mountain permafrost is approx.
850 m long, 200 to 350 m wide, and stretches vertically between
2455 m and 2725 m altitude. Over the course of time, the snout
of the rock glacier has advanced into the uppermost cirque’s
lip, which is much steeper than the cirque floor behind, causing
disintegration of this part of the rock glacier through active
sliding processes (since 1994). Consequently, flow velocities
behind the frontal slope have significantly increased because of
a lack of counterpressure. Maximum horizontal flow velocities
reached 2 to 2.5 m a-1. The prevailing high longitudinal strain
rates of up to 20´10-3 a-1 (2002-2006) have triggered surface
ruptures and crevasse-like openings. In this paper we present
quantitative information on the kinematics and surface
deformation of the rock glacier based on the photogrammetric
evaluation of multi-temporal aerial photographs (10 different
epochs between 1954 and 2006) and annual geodetic measurements
(1999-2007). Results obtained from recent investigations are
highlighted. Based on the available information, covering a time
span of 52 years, we analyze the changing kinematic state of
Hinteres Langtalkar rock glacier. Special emphasis is put on the
more recent situation of the rock glacier, which is
characterized by the rapid development of tension cracks and the
accelerated disintegration of the permafrost body. The main
findings of this paper are as follows: (1) There is most
probably a persistent climatically-induced permafrost melt in
the order of a few centimeters per year. (2) Specific
topographic situations (e.g. increasing slope inclination) may
cause acceleration of flow/creep of a rock glacier, with the
implication of possible surface ruptures in case of high strain
rates and insufficient internal cohesion. (3) Interannual
changes of flow/creep velocities are most probably due to the
thermal conditions of the permafrost body, more or less true
irrespective of (2). Furthermore, the authors propose to augment
the present monitoring program by a high-resolution airborne
laser scanning (ALS) mission which should be repeated (at least
once) at a time interval of several years depending on the
height accuracy to be achieved and the prevailing permafrost
melt.
Keywords:
permafrost, rock glacier, long-term monitoring, geodetic and
photogrammetric survey, flow velocity, geomorphometry, Hinteres
Langtalkar rock glacier, Hohe Tauern range, Austria.
Paper presented at the 10th International Symposium on High
Mountain Remote Sensing Cartography, 8-11 September 2008,
Kathmandu, Nepal.
The Influence of Air Temperature on the Creep Behaviour of Three Rockglaciers in the Hohe Tauern
S. Buck and V. Kaufmann
Institute of Landscape Ecology
Westfälische Wilhelms-University Münster, Germany
e-mail: buck-stefan@web.de
Abstract
The aim of this paper is to demonstrate the link between air temperature and the creep behaviour of three active rockglaciers. These are the Doesen, Hinteres Langtalkar and Weissenkar rockglacier, which are all located in the Hohe Tauern range, Eastern Alps, Austria. The surface motion of the investigated rockglaciers was measured using photogrammetric and geodetic methods. Exact annual displacement rates of at least the last ten years are the basis of this study. A comparison and analysis of the horizontal and vertical displacement rates revealed a rather homogenous and synchronous behaviour of the three rockglaciers despite their different size, morphology, complexity and mean annual velocity. The observed homogeneity led to the assumption that interannual variations are caused by external climatic factors. The horizontal displacement rates show a fairly clear correlation with variations in mean annual air temperature (MAAT) with a delay of about a year caused by their delayed propagation deeper into grounds. However, the vertical displacement rates seem to react quicker to the MAAT. Furthermore, the horizontal displacement rate of the Hinteres Langtalkar rockglacier is exemplary compared to the ice thickness change of the Goessnitzkees, a nearby small debris-covered cirque glacier. The objective is to show similarities between them, as this also indicates the dependency of flow velocities of rockglaciers on air temperature.
Keywords: Hohe Tauern, rockglaciers, creep, horizontal and vertical displacement, interannual variations, MAAT.
Paper presented at the 10th International Symposium on High Mountain Remote Sensing Cartography, 8-11 September 2008, Kathmandu, Nepal.
Quantification and Visualization of Periglacial Surface Deformation in the Inneres Hochebenkar Cirque, Ötztal Alps, Austria
V. Kaufmann
Institute of Geodesy
Graz University of Technology
Steyrergasse 30, A-8010 Graz, Austria
Tel.: +43 316 873-6336, Fax: +43 316 873-6337
e-mail: viktor.kaufmann@tugraz.at
Abstract
Inneres Hochebenkar is a high-mountain
cirque (approx. 0.84 km2) located in the Gurgl
valley, Ötztal Alps, Tyrol. It holds not only a rock glacier (of
the same name) but also a small glacier (Hochebenferner) in its
root zone. During the Little Ice Age (last glacial maximum at
around 1850) the Inneres Hochebenkar cirque was largely covered
by the Hochebenferner glacier, which has now receded to a small
remnant (8.3 ha in 2006). The main focus of the present paper is
to document the past and also more recent surface change of the
periglacial (= non-glaciated) environment of the Inneres
Hochebenkar cirque. Remote sensing data, such as time-series of
aerial photographs (1953-2010) and airborne laser scanner data
(2006, 2010), were used to retrieve quantitative information on
surface change, i.e., horizontal movement and/or surface height
change. The results obtained are presented graphically (two
separately moving rock glacier units connected by a small unit
of inactive, but melting permafrost at the lower end of the
cirque) and numerically (e.g., maximum mean annual creep
velocities of up to 46.7 cm/year for the time period 2003-2010
and maximum surface lowering of -10.8 m for the time period
1953-2006). Special attention is also paid to proper
visualization, i.e. computer animations, of areas of presumed
surface change using time-series of both high-resolution
orthophotos and shaded reliefs.
Paper presented at the 10th ICA Mountain Cartography Workshop, 26-30 April 2016, Berchtesgaden, Germany.
last update: july 31, 2017
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