Geomorphologia Slovaca et Bohemica 2/2011
Content/Obsah
JAROMÍR DEMEK - PETER MACKOVČIN - PETR SLAVÍK: Impacts of Coal Mining on Relief: Case Study of the Trojanovice Mine Area, the Moravian-Silesian Carpathians, Czech Republic .: Download PDF :.
PAVEL BELLA: Geomorfologické faktory priestorovej diferenciácie, časových a časopriestorových zmien jaskynných geosystémov .: Download PDF :.
IVICA MILEVSKI: Morphometric classification of high mountain ranges in the Republic of Macedonia .: Download PDF :.
SANDU BOENGIU - OANA IONUŞ - DANIEL SIMULESCU - LILIANA POPESCU: River undercutting and induced landslide hazard. The Jiu River valley (Romania) as case study .: Download PDF :.
MILAN FRANDOFER - MILAN LEHOTSKÝ: Channel adjustment of a mixed bedrock-alluvial river in response to recent extreme flood events (The upper Topľa River) .: Download PDF :.
SPRAVODAJCA ASG PRI SAV 2011.: Download PDF :.
Abstracts/Abstrakty
Jaromír Demek, Peter Mackovčin, Petr Slavík: Impacts of Coal Mining on Relief: Case Study of the Trojanovice Mine Area, the Moravian-Silesian Carpathians, Czech Republic Geomorphologia Slovaca et Bohemica, 11, 2011, 2, 7 - 18. 6 figs., 26 refs.
The aim of the paper is to predict and estimate the impacts of the planned hard coal mining in Trojanovice mine area underneath the sensitive Moravian-Silesian Carpathians and the impact of mining activities on relief. The planned underground mining activities will accelerate geodynamic processes in the area and cause substantial changes in the young mountainous relief. The impacts of underground hard coal mining in such sensitive young mountains are difficult to predict since actual topographical changes can be significantly different from those predicted by an OKD computer model based on conditions in the lowland part of the Upper Silesian Coal Basin. The authors present a 3D engineering-geomorphological model of expected impacts of the coal mining project on the relief of the western part of the Trojanovice Mine Area. Key Words: impact of underground coal mining on relief, geohazards, engineering geomorphology, the Moravian-Silesian Carpathians, the Trojanovice Mine Area, Czech Republic
Pavel Bella: Geomorphological factors of spatial differentiation, time and time-spatial changes of cave geosystems Geomorphologia Slovaca et Bohemica, 11, 2011, 2, 19 - 31. 4 figs., 3 tab., 49 refs.
Geomorphological forms belong to the major differentiating factors of spatial structure and diversity of cave geosystems. From a geomorphological point of view the spatial structure of cave geosystems hierarchically consists of speleomorphotopes (geomorphologically basic quasi homogenic units of topic dimension), speleomorphochores (consist of two or more adjoining speleomorphotopes linked by recent or former horizontal relations, relative homogenic units of choric dimension) and sets of speleomorphochores (adjoining speleomorphochores associated to actual or relict functional units of a higher hierarchy level of choric dimension). Time and time-spatial changes of cave geosystems are interpreted by seasonal regime or etocycles of geomorphological processes, successional dynamics conditioned by a geoecological invariant, evolution with an alternation of geoecological invariants and a change of spatial structure. Considering geomorphological attributes the spatial diversity of cave geosystems is qualified based on different morphometric, morphological, genetic and morphodynamic features of cave passages and other segments of speleorelief. The delineation and typology of speleomorphotopes is the fundament for a determination of spatial diversity of cave geosystems. The time variability of cave geosystems is mainly given by a number or frequency of changes of geomorphological processes. Key words: karst geomorphology, geoecology, speleology, cave environment, spatial structure and diversity, regime of geomorphological processes, succesional dynamics, cave evolution
Ivica Milevski: Morphometric classification of high mountain ranges in the Republic of Macedonia Geomorphologia Slovaca et Bohemica, 11, 2011, 2, 32 - 45. 6 figs., 9 tabs., 30 refs.
As a result of powerful local and regional geotectonic movements in the past, the landscape in the Republic of Macedonia is characterized by frequent alternations between mountains and depressions. There are 38 mountain ranges, of which 13 extending above 2,000 m are defined as high, while the highest - Korab – reaches 2,753 m a. s. l. Because of their geomorphological and overall significance, morphometric features of these 13 dominant high mountain ranges are analysed in this work. The data are calculated from a previously prepared 3”SRTM-based DEM model with particular attention to hypsometry, slope gradient and aspect, and vertical relief. Based on these variables, a simple supervised classification of the high mountain ranges is made. Key words: morphometry, mountain ranges, supervised classification, 3”SRTM DEM
Sandu Boengiu, Oana Ionuş, Daniel Simulescu, Liliana Popescu: River undercutting and induced landslide hazard. The Jiu River valley (Romania) as case study Geomorphologia Slovaca et Bohemica, 11, 2011, 2, 46 - 58. 10 figs., 42 refs.
The paper aims at synthesising the geomorphologic background for the evolution of the right slope of the Jiu River valley. The investigation of numerous landslides helped to decipher the mechanisms that trigger them and influence the spatial distribution of areas vulnerable to mass movements. For the analysis of mass movements processes, there were used geological and climatic data, as well as topographic measurements, geomorphologic mapping; based on the aerial surveys from different periods, the changes that occurred were analysed. Topographic measurements carried out within the areas with fossil and active landslides and along the right bank of the Jiu River valley, in the sectors with strong lateral erosion, were carried out twice a year, beginning with the spring of 2006. When some of the landslides were reactivated or there were high flows of the Jiu River, measurements were also carried on, apart from the regular ones in spring and autumn. From the confluence with the Motru River until flowing into the Danube River, the Jiu River is undercutting the right slope of the valley. During the Quaternary, the Jiu River had a tendency to deviate to the west due to the different elevation speeds, higher in the east and lower in the south, recorded in the western compartments of the Moesian Plate. The base level lowered, causing the deepening of the valley up to 130 m and climatic fluctuations lead to the loess deposition and oscillations in the flow. All these facts cause river undercutting. The encountered structures are monoclinal with inclination from north-west to south-east in the Getic Piedmont and tabular in the Romanian Plain, and lithologically they belong to the sedimentary complexes formed of often cemented sands and gravel in alternation with marls and clays. The violent erosion of the right slope has lead to a total change in the geomorphologic systems mainly by increasing the slope energy, by beheading the tributary valleys and by deepening the river bed below the level of grey clays and marls of Romanian age. Currently the entire slope is affected by mass movements (slumps and landslides) with a common mechanism: where the convex part of the meanders approaches the slope, its vulnerability increases and leads to slumps and landslides and where the slope is far from the course or near the concave part of the meanders, the vulnerability decreases and the slope tends to become a glacis. In most cases the Jiu River moves away from the right slope next to the confluences with tributaries on this side, because immediately afterwards, it returns close to the slope. This slope is under the direct influence of the Jiu River, which regularly unbalances the slope, maintaining a fast dynamic and an increased geomorphologic risk on the settlements, agricultural land and infrastructure. Key words: landslides, river undercutting, neotectonics, the Jiu River
Milan Frandofer, Milan Lehotský: Channel adjustment of a mixed bedrock-alluvial river in response to recent extreme flood events (The upper Topľa River) Geomorphologia Slovaca et Bohemica, 11, 2011, 2, 59 - 71. 11 figs., 4 tabs., 28 refs.
Recent increasing of magnitude and frequency of extreme flood events leads to exaggeration of the fluvial processes. Spatial and temporal aspects of extensive channel adjustment of the Topľa River in its piedmont segment are discussed. The changes of channel pattern were analyzed using remotely sensed imageries, whereas the vertical erosion was established by analysis of 78 cross-sectional profiles. Considering the relatively low size of the river (4th – 5th Strahler ord.), vast area was stricken with the active bank erosion during flood of June 2006 (1.42 ha) and July 2008 (3.43 ha). In addition, another flood in June 2010 occurred, but its effect was mostly vertical on average 0.33 m. Spatial distribution of the intensity of the processes of bank erosion and bed incision during these extreme events are suggested to be driven primarily by their magnitude (represented by discharge) and by channel inclination. Nevertheless, local controls such as presence of bedrock bottom or large woody debris jams bring uncertainties and contribute to nonlinear behavior of river channel during extreme events. Key words: channel pattern, bedrock-alluvial channel, channel cross-section, extreme flood events, the Topľa River