Jan Kalvoda

Geomorphological hazards in high mountain areas

Dedication to Professor Clifford Embleton. Prologue. Sedimentology and Clast Orientation of Deposits Produced by Glacial-Lake Outbursts Floods in the Mount Everest Region, Nepal D.A. Cenderelli, E.E. Wohl. Catastrophic Floods and Flushing of Sediment, Western Himalaya, Pakistan J.F. Shroder, et al. Landslides and Deserted Places in the Semi-Arid Environment of the Inner Himalaya J. Baade, et al. Glacier-Induced Hazards as a Consequence of Glacigenic Mountain Landscape, Glacier and Moraine Dammed Lake Outbursts and Holocene Debris Production M. Kuhle, et al. Chaos Theory of Slides/Mud Flows in Mountain Areas. Example: Xiaojiang Basin, NE Yunnan, China A.E. Scheidegger. The Salt Weathering Hazards in Deserts A. Goudie. Impact of Conversion of Upland Forest to Tourism and Agricultural Land Uses in the Gunung Kinabalu Highlands, Sabah, Malaysia W. Sinun, I. Douglas. Landslides in the Rocky Mountains of Canada D.M. Cruden, X.Q. Hu. Late Holocene Sturzstroms in Glacier National Park, Montana, U.S.A. D.R. Butler, et al. Storm Induced Mass-Wasting in the Oregon Coast Range, U.S.A. C.L. Rosenfeld. Natural Hazards in Relation to Present Stratovolcano Deglaciation: Popocatepetl and Citlatepetl, Mexico D. Palacios. Andean Landslide Hazards T.A. Blodgett, et al. Fluvial Hazards in a Steepland Mountain Environment, Southern Bolivia J. Warburton, et al. Geomorphological Response of Neotectonic Activity Along the Cordillera Blanca Fault Zone, Peru V. Vilimek, M.Z. Luyo. Geomorphological Hazards and Risks in the High Tatra Mountains J. Kalvoda. Geomorphologic Hazards in a Glaciated Granitic Massif: Sierra de Gredos, Spain D. Palacios, J. de Marcos.

Increased Uric Acid and Glucose Concentrations in Vitreous and Serum of Patients with Diabetic Macular Oedema

Background: Diabetic retinopathy (DR) is characterized by blood-retina barrier breakdown induced by local changes in the retina and systemic factors. We investigated vitreous and serum levels of glucose and uric acid (UA) in patients with DR and aimed to describe their correlation with the grade of DR. Methods: Prospective study of 81 patients with DR and 48 non-diabetic controls. Biochemical analysis of vitreous and serum samples was performed. Results: UA and glucose concentrations in vitreous and serum were significantly higher in diabetic patients than in controls. Absolute ratios (vitreous level/serum level) of UA and glucose were higher in proliferative compared with non-proliferative DR. Conclusions: The results suggest that, apart from glucose, increased levels of UA in diabetic patients may also be involved in the pathogenesis and progression of DR.

MASS DISTRIBUTION OF EARTH LANDFORMS DETERMINED BY ASPECTS OF THE GEOPOTENTIAL AS COMPUTED FROM THE GLOBAL GRAVITY FIELD MODEL EGM 2008

Correlations of large-scale landform patterns with some aspects of the geopotential as computed from the global gravity field model EGM 2008, particularly the radial second derivatives of the disturbing gravitational potential Γ33, the strike angle θS and virtual deformations of the ellipse of deformation, are demonstrated. Selected regions with documentation of aspects from EGM 2008 are the Nepal Himalaya and its neighbouring areas, the collision zone of East-Asian and West-Pacific lithospheric plates, the contact region of north-eastern Africa, south-western Asia and south-eastern Europe, morphotectonic contact between the Bohemian Massif, Eastern Alps and the Western Carpathians in Central Europe and regions of ancient rapid events indicated by relics of large impact craters Vredefort, Chicxulub and Popigai. It is suggested that landform patterns with very conspicuous combinations of significantly high positive or negative values of Γ33 are under the strong influence of rapid and/or intensive geomorphic processes. These geophysical signatures supported by values of the strike angle θS and virtual dilatations or compressions of the ellipse of deformation reflect the regional dynamics of Earth surface evolution as characterised by a very effective integration of tectonic and climate-driven morphogenetic processes.

Geomorphology and the location of nuclear power plant sites: the Czechoslovakian experience

The need for secure sites for such sensitive installations as nuclear power plants and radioactive waste storage has brought increasing significance to the study of the geodynamic processes of the Earths crust. Among other Earth sciences, geomorphology in Czechoslovakia is also participating in the study of both planning and operating nuclear power station sites. The experience of Czech geomorphologists has shown that the geomorphological information is necessary part of the accurate prediction of events and time which can endanger the security of nuclear power plants, radioactive waste storages, pipelines and other large installations. Geomorphological mapping and morphostructural analysis are important tools for such studies.

Gravity Disturbances, Marussi Tensor, Invariants and Other Functions of the Geopotential Represented by EGM 2008

Gravity disturbances, the Marussi tensor, invariants of the gravity field, their certain ratio and other functions of the geopotential (including newly defined “virtual deformations”) are computed based on the harmonic coefficients of the global gravitational field model EGM 2008. Regional examples of correlations of large-scale morphotectonic and landform patterns with some aspects of the geopotential as computed from the EGM 2008 are presented. It is suggested that morphotectonic and landform patterns with very conspicuous combinations of significantly high positive or negative values of Γ33 are under the strong influence of rapid and/or intensive geomorphic processes. These geophysical signatures supported by values of the strike angle θS and virtual dilatations or compressions of the ellipse of deformation reflect the regional dynamics of Earth surface evolution as characterised by a very effective integration of tectonic and climate-driven morphogenetic processes. Key wordsEarth Gravitational Model 2008; gravity disturbances; the Marussi tensor; invariants of the gravity field; virtual deformations of the ellipse of deformation; landform patterns; geodynamics.

The origin and evolution of Iskanderkul Lake in the western Tien Shan and related geomorphic hazards

ABSTRACT The origin and evolution of Iskanderkul Lake are studied in relation to geomorphic hazards within a broader area of interest. It is shown that the giant Kchazormech rockslide with its volume of masses of approximately 1 km3 entirely blocked the Iskanderdarja river valley, likely in the Middle Holocene, impounding thus the palaeolake of Iskanderkul. Geomorphological evidence indicated that the palaeolake suddenly decreased its volume by 83% and its areal extent by 65% and released 0.84 ± 0.1 km3 of water. The present-day Iskanderkul Lake is therefore considered as a remnant of a much larger palaeolake of Iskanderkul. Recent slope movements, incision and backward erosion of rockslide accumulation leading to the formation of a bypass gorge are documented. Current geomorphic hazards are outlined and the near-future evolution of Iskanderkul Lake is discussed with respect to the ongoing climate change suggesting a relatively low longevity of lakes in the Tien Shan.

Geomorphological Hazards and Risks in the High Tatra Mountains

For its diversified landscape and the quantity of research problems it offers, the quaint nature of the High Tatra Mountains merits the permanent attention of natural scientists. The territory of the Tatras National Park in the Slovak Republic (Fig. 1) displays a unique natural environment in Central Europe both by its geomorphological evolution history and unique biosphere complex. The topic of this paper is to emphasize the natural hazards of the alpine-type relief manifested mainly by different types of slope movements and anthropogenous share of geomorphological hazards and risks in the Tatras National Park.

SUMMAR Y OF PAPERS BY CZECH PARTICIPANTS AT THE XVIIITH INQUA CONGRESS IN BERN

The review paper presents the main research topics of the XVIIIth INQUA Congress from selected sessions with contributions from the Czech participants. The results of Czech papers are highlighted and discussed in relation to progress in Quaternary research. Discussed are advances in topical subjects of international studies of Quaternary palaeoenvironments and climate change.

LANDFORMS AND MORPHOGENETIC PROCESSES IN THE LOCALITY OF GEODETIC OBSERVATORY PECNÝ, ONDŘEJOVSKÁ VRCHOVINA HIGHLAND

The presented paper deals with physical-geographical environment and landform patterns in the locality of Geodetic Observatory Pecný (GOPE) in the Ondřejovska vrchovina Highland. Landforms transience of the Ondřejovska vrchovina Highland by erosion and denudation processes is proportional to a high potential energy of the relief due to progressive tectonic uplift of the central part of the Bohemian Massif in the late Cenozoic. The Seradovský potok Brook valley between the Pecný Ridge (545 m a.s.l.) and the Sazava valley bottom (284 m a.s.l.) intersects several levels of planation surfaces and its source area erodes the etchplain exhumed during the Palaeogene. In the lower part of the valley, the stream deepened during the late Quaternary by approximately 50 m, whereas the relatively steep erosional slopes of the canyon-like part of the antecedent Sazava valley have a relative height of 60–75 m. In the rugged terrain of the GOPE locality, there are visible marks of regelation and frost processes, gully and fluvial erosion, slow slope movements and anthropogenic activities. Intensity of recent morphogenetic processes with its maximum in spring corresponds to combination of seasonal changes of air and soil temperature and at the same time to increased water content in the rock massif and in the weathered mantle. The suitable geodynamic location of scientific observatories on the Pecný ridge, stable from engineering-geological and geomorphological point of view, and in its near neighbourhood is menaced by increasing intensity of anthropogenic activities in the landscape.

The Geomorphological Evolution and Environmental Hazards of the Prague Area

Landform evolution of the Prague area in the central part of the Bohemian Massif was controlled by the coupled occurrence of episodic tectonic uplift and variable climato-morphogenetic processes during the Cenozoic. Much older geological history of the region commenced in the Precambrian times and was very diverse in terms of transformations of the natural environment. Present-day landform patterns of the Prague area are determined by epigenetic and antecedent deepening of canyon-like valleys of the Vltava River and its tributaries to large planation surfaces during the Quaternary. These dynamic processes have led to the origin of river accumulation terraces as well as erosion and denudation slopes with weathered mantle of deposits. The extraordinary geodiversity and biodiversity of the landscape in the Prague area is associated with geomorphic hazards , including devastating floods and landslides . Prague is also faced to severe impact of modern urban development and related human activities on the architectural heritage .