Adam Kotarba

Abstract

Debris flows constitute the dominant high-energy slope processes in the high-mountainbelt of the Tatra Mountains, the Alps and other European mountain massifs. Rainfall intensitiesresponsible for triggering recent flows include that of ca 35–40 mm in one hour. Undersuch a condition, whole talus slopes several hundred meters long are affected by rapid flow inthe High Tatras, on both the Polish and Slovak sides, and the maximum volume of debris removedand accumulated by such events is ca. 25,000 m3 . Debris flows with a maximum volume ofca. 500,000 m3 are triggered by rainstorms of similar totals and intensities in the Alps.

Keywords: debris flows, extreme rainfall events, Tatra Mountains, European geomorphic hazards

Adam Kotarba [kotarba@zg.pan.krakow.pl], Institute of Geography and Spatial Organization Polish Academy of Sciences, Św. Jana 22, 31-018 Kraków, Poland

Abstract

The age of recent glacial, glacifluvial/fluvial forms is determined using lichenometric dating in two Alpine valleys of the Massif des Ecrins in France. A lichen growth-curve is based on data from natural sites, such as boulder-fields, moraine ridges etc. of known age on recently deglaciated terrain. The maximum extent of the glacial system of the Veneon and Etangons valleys during the Little Ice Age was 15 km in length. The maximum lichen diameter of 90-95 mm characterizes the stage of recession correlated with AD. 1650-1660. Analysis of the systems of terraces and paleochannels of the progla-cial rivers supported by lichenometric dating allows three periods of intensified fluvial activity to be distinguished for the Little Ice Age.

Keywords: deglaciation landforms, lichenometry, Little Ice Age, Massif des Ecrins, France

Maria Baumgart-Kotarba, Institute of Geography and Spatial Organization Polish Academy of Sciences, Św. Jana 22, 31-018 Kraków, Poland
Jean-Paul Bravard, Université de Lyon 2, Faculté GHHAT, 5, av. Pierre Mendes, 69676 Bron, France
Michel Chardon, Institut de Géographie Alpine, 14 bis av. Marie-Reynoard, 38100 Grenoble, France
Vincent Jomelli, Institut de Géographie, Université Paris I-Sorbonne, 191, rue Saint-Jacques, 75005 Paris, CNRS Laboratoire de Géographie Physique 1, pl. A.Briand 92195, Meudon Cedex, France
Stanisław Kędzia [kedzia@zg.pan.krakow.pl], Institute of Geography and Spatial Organization Polish Academy of Sciences, Św. Jana 22, 31-018 Kraków, Poland
Adam Kotarba [kotarba@zg.pan.krakow.pl], Institute of Geography and Spatial Organization Polish Academy of Sciences, Św. Jana 22, 31-018 Kraków, Poland
Pierre Pech [pierre.pech@univ-paris1.f], Institut de Géographie, Université Paris I-Sorbonne, 191, rue Saint-Jacques, 75005 Paris, CNRS Laboratoire de Géographie Physique 1, pl. A.Briand 92195, Meudon Cedex, France
Zofia Rączkowska [raczk@zg.pan.krakow.pl], Institute of Geography and Spatial Organization Polish Academy of Sciences, Św. Jana 22, 31-018 Kraków, Poland

Abstract

An alpine cliff and related to it talus slope* are the most typical features of mountainous areas transformed by glaciers. The development of a young cliff starts at the moment when the inclined rock surface becomes free of ice. Very often such surfaces are very steep, vertical or even overhanging and devoid of weathered material. Weathering processes on rock surfaces produce debris which is transported downslope due to gravitational processes such as falling, sliding and toppling. Principal debris slope units formed below cliffs are differing from each other in terms of grain size composition and sorting. Active and non-active or partially active slope surfaces occur adjacent to each other. They are the diagnostic features of past and contemporary periglacial/cryonival environment. Therefore, talus slope features are good indicators of postglacial evolution. Seven types of cliff-debris slope systems have been distinguished in this paper.

Adam Kotarba [kotarba@zg.pan.krakow.pl], Institute of Geography and Spatial Organization Polish Academy of Sciences, Św. Jana 22, 31-018 Kraków, Poland

Abstract

The Middle-Khalkhasian Upland which exists on the southern foreland of theKhentei in Mongolia separates these mountains from the Gobi Plain. Even if thisplateau is actually riverless the landscape is characterized by a net of broad andlong valleys. Period of valley formation is correlated with the Pleistocene when thearea was modelled by large permanent rivers flowing from the North to the Southunder humid and severe climatic regime. Soil covers on slopes contain features ofthe ancient humid climate as well as of dry continental climate (Kowalkowski andLomborinchen 1975). They indicate very advanced slope evolution and infilling oftectonic undrained depressions of this technically active region in the Holocene.Discontinuous permafrost which exists at present was also responsible for theHolocene morphogenesis.

The programme of field works was concerned mainly with the manner of slopedevelopment after the phase of Pleistocene pluvio-fluvial erosion and contemporaneousgeomorphic processes. Periglacial slopes located in higher elevations were excludedfrom this study as they have been analysed separately (Kotarba 1980).

Adam Kotarba [kotarba@zg.pan.krakow.pl], Institute of Geography and Spatial Organization Polish Academy of Sciences, Św. Jana 22, 31-018 Kraków, Poland