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  • Author: Dávid Tomko-Králo x
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Abstract

In the report we concentrate on the influences of water-induced morphodynamic processes and surface flow on the development of tarns in alpine environment conditions of selected valleys in the High Tatras. Model areas are represented by higher basins parts in the Malá Studená valley and the Veľká Studená valley, where we confirmed that slope-gravitational processes in the form of rockfall, water-gravitational processes in the form of debris flows, but also fluvial-proluvial processes as the accumulation of the soft fractions from the area of debris cones take part in the material deposition in the tarns. In this context we focused on the creation of the model of spatial distribution of the water-induced potential of material deposition in drainage tarn basins. The model includes three basic factors: slope and curvature of the relief and land cover character. Map processing with GIS technologies was done on the basis of a 3-D relief model, which allowed the locating of the local erosion bases areas, where the material could be accumulated. The achieved results confirmed the hypothesis that tarn basin development of the alpine environment is subordinated to permanent backfilling as a consequence of the cumulative influence of the several processes connected with rainfall and the runoff regime of the drainage basins.

Abstract

Tatra’s lakes are vulnerable ecosystems and an important element of the alpine landscape. Mainly some shallow lake basins succumb to intense detritus sedimentation, fine fractions of material from the catchment area or to the overgrowing of water level by vegetation. In this paper, changes and dynamics of the 12 Tatra’s lake shorelines that were selected based on the detailed mapping of their extent are pointed out. Changes were assessed by accurate comparisons of historical and current orthophoto maps from the years 1949, 1955 and 2015 – and therefore, based on the oldest and the latest relevant materials. Due to the overgrowing of lakes caused by vegetation, their water surface decreased from −0.9% up to −47.9%, during the examined period. Losses were caused by the overgrowing of open water surface by the communities of sedges and peat bogs. The most significant dynamics of the shorelines during the last decades were reached by those lakes, into which fine sediments were simultaneously deposited by means of mountain water coarse. These sediments made the marginal parts of the lake basins shallower and accelerated rapid expansion of vegetation to the detriment of the open water surface. The overgrowing of shallow moraine lakes lying in the vegetation zone is a significant phenomenon of the High Tatras alpine landscape. It leads to their gradual extinction, turn into peat bogs and wet alpine meadows.