Electronic Library of Scientific Literature - © Academic Electronic Press
Volume 54 / No. 1 / 2002
Š. Majtán, H. Omura, K. Morita: Fractal dimension as an indicator of probability for landslides in north Matsuura, Japan. Geografický časopis, 54, 2002, 1, 5 figs., 2 tabs., 17 refs.
Fractal dimension as an indicator of similarity, density, complexity and frequency seems to be useful for analysing susceptibility assessment, distribution pattern. It can also be used as a comparable factor. To indicate the spatial distribution of the shallow landslide quantitatively, their fractal dimensions and probabilities were estimated in an landslide area north of Nagasaki in Japan. In order to calculate the fractal dimension, capacity and information dimensions were selected. Landslides were grouped on the basis of surface geometry analysis and geology of the study area. The probability of occurrence of landslides in an individual landslides group was calculated on the basis of the relationship between the ratio of the average landslide area and area of the landslide group and fractal dimension.
Key words: surface analysis, distribution, landslide, fractal dimension, probability
J. Malgot, F. Baliak: Influence of human activity on the development of landslides in Slovakia. Geografický časopis, 54, 2002, 1, 20 figs., 10 refs.
About 90 % of new landslides take place by activation of potential landslides due to man̉’s negative intervention in Slovakia. Antropogeneous interventions act on the stability of old, dormant landslides differently. The landslides are either artificialy loaded or undercut. Man’s activity induces changes in the regime of groundwaters or causes dynamic effects on the landslides. The paper analyses the cases of activization of old landslides due to the construction of civil or industrial structures, bridges, roads, tunnels, pipe-lines and water artificial reservoirs. Numerous landslides were induced by deforestation of land, incorrect agricultural melioration works, worsening of flow – off surface and underground waters and failures of the underground pipe-lines. The high number of artificially activated dormant landslides in the areas with an intense economic activity in Slovakia is alarming. With the constantly increasing urbanization of Slovakia, it can be expected that this trend will be maintained in the future, if we do not learn from the present mistakes. Man’s activity in the densely populated areas is becoming the most important geological factor. Its influence is activating landslides of bigger dimensions, which usually cause the biggest damage. However, the risk of renewing movements of old landslides may be reduced to the minimum, when we know the degree of danger, which threatens all the planned and existing structures in the sliding areas.
Key words: Slovak Republic, landslides, activation of movements, negative antropogenous activity
G. Janicki, J. Rodzik, W. Zgłobicki: Geomorphic effects of land use changes (a case of the Gutanów loess catchment, Poland). Geografický časopis, 54, 2002, 1, 5 figs., 3 tabs., 31 refs.
The study discusses the influence of land use changes on relief development in a small loess catchment with medium denivelations, located in the Lublin Upland (SE Poland). The denudation rates in the past were determined by field analysis of the soil profiles, and its present-day rate was calculated by the caesium-137 method. An attempt to determine the changes of the soil erosion rate during the 620 year period of land cultivation was undertaken. The mechanism of development of the anthropogenic relief forms and their influence on the changes in intensity of the episodic surface runoff was also analysed. A considerable influence of the field pattern, tillage direction and location of country roads on the intensity of geomorphological phenomena was observed.
Key words: SE Poland, loess catchment, soil erosion, anthropogenic relief, denudation balance, episodic processes
T. Ziętara: The role of debris-mud flows in devastation of settlement infrastructure in the Flysch Carpathians. Geografický časopis, 54, 2002, 1, 6 figs., 58 refs.
The paper presents potential threats caused by debris and mud flows in the Flysch Carpathians. There were 6 disastrous floods in the Carpathians during the last 50 years. They caused great changes in relief and destruction of economic infrastructure. Debris and mud flows are created during long term and heavy precipitation and they are of great destructive strength. Morphodynamic zones in the Carpathians with different frequencies of debris and mud flows were distinguished. A typology of flows was also presented according to the size of heavy precipitation, geological structure and relief.
Key words: Flysch Carpathians, mud and debris flows, landslides, disastrous floods
J. Sobocká, P. Jambor: Water erosion control in conditions of a geomorphologically dissected area. Geografický časopis, 54, 2002, 1, 1 fig., 1 tab., 10 refs.
A problem of landscape consolidation, or land arrangement in conditions of large-scale farming is presented. The pilot area of the Agricultural Manufacture and Trade Co-operative of Kočín, which farms soils regularly damaged prevailingly by water erosion (dominant soil profile Haplic Luvisols from loessial parent material) was treated by comprehensive physical-geographical analysis. Evaluation of the present agricultural practices was also helpful. We have investigated and proposed a system of water erosion control like new landscape arrangement (optimum field size and shape, proposals for a new road network), contour agrotechnics, no-till minimum technics, green corridors and terrace construction.
Key words: water erosion, erosion control, landscape consolidation
J. Hanušin: Hydrological and geomorphological aspects of different farming practices. Geografický časopis, 54, 2002, 1, 3 figs., 14 refs.
The aim of the paper is an attempt to demonstrate the need to reevaluate some simplifying views of the influence collectivization exerted on soil loss processes in agricultural landscape, which indiscriminately suggest the increase of intensity of such processes after collectivisation. Single parameters of soil loss process controlled by man, relevant to land use patterns in the pre- and post-collectivization periods using evaluations of two model territories were analysed. Results of analysis indicate that after collectivization changes of numerous parameters, in spite of prevailing estimates, caused the decrease of soil loss processes on many places. Evaluation of agro-technology from the viewpoint of susceptibility to the soil loss process was also considered. The obtained results revealed that the collectivization process or the method of farming under collectivization can be in no way one-sidedly and indiscriminately blamed of increased rate of the soil loss process in comparison with the pre-collectivisation era. Reliable comparison of the effect of the land use changes on soil loss processes calls for individual approach taking into consideration the particular circumstances in each case.
Key words: soil loss process, agricultural landscape, collectivization, land use pattern, changes of soil loss process intensity controlled by man
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