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Geomorphology

Volume XVI |

The influence of contributing area parameters on the size of rock glaciers in the Southern Carpathian Mountains

Abstract: The paper aims to determine to what extent the size of the rock glaciers (RG) in the Southern Carpathians (Romania) is influenced by their contributing area (CA) parameters. Simple linear regression (LR) and generalized linear models (GLM) were used to meet this goal, considering as independent variables the main morphometric characteristics of the contributing area. The LR coefficients revealed that the most influential variables were the width (R2=0.57) and the size of the CA (R2=0.51). Based on the best GLM results the size of the rock glaciers can be statistically explained quite well  (R2=0.58) by a combination of three variables: CA length, CA width, and the minimum altitude of the CA. Rock glaciers are thus complex landforms resulting from a combination of many variables (climatic, topographic and geologic) including contributing area parameters. Both LR and GLM analysis revealed that the size of the rock glaciers can only be partly explained by the characteristics of the CA. The study revealed that GLM are powerful analytical tools which give reasonable results when analysing the role of rock glaciers developmental controls.

Volume XVI |

Changes of the karst landscape and epikarst system in the area of the Tapolca karst terrains, North-West Balaton Highlands, Hungary

Abstract: The caves in Hungary have been protected for a long time. The current national legislation on nature conservation states that all known and unknown caves are under ex lege protection but the karst areas above them are not. The territories above the caves can be owned by the state but also some of them belong to private owners, thus a great diversity of economic activities are conducted on them. Anthropogenic activities endanger both directly and indirectly the caves environment and the karst ground waters. The damages and pollution of caves take place through the epikarst systems which are in direct connection with the topographic ground surface. Therefore, it is of special significance to emphasize the natural processes taking place in epikarstic systems as well as to analyze the changes within epikarst terrains caused by human impacts. The effects of human impacts on epikarst system in the area of the Tapolca karst were analyzed both by field and laboratory methods. The historical evolution of land cover and land use was assessed related to the impact on the abiotic elements (soil and karstic cover-deposit, water) in Tapolca area. The intrinsic vulnerability was assessed using the semi-quantitative COP Method. The results show high resource vulnerability in all analyzed epikarstic sites.

Volume XV |

Shape characteristics of fluvial islets based on GIS techniques. A case study: the Danube’s islets between Giurgiu and Olteniţa

Abstract: This study aims to quantitatively characterize shape parameters of fluvial islets using GIS techniques. There were eight metrics selected for the analysis. For the automation of the workflow, all processing functions were joined into a single graphical model. For this case study we selected the Danube sector situated between the cities Giurgiu and Oltenita. We chose to track the evolution of the fluvial islets’ shapes from 1864 to 2010. Information was extracted from historical data sources such as maps and ortophotoplans. The graphical model created was run for each studied year.
The results show major changes in the aspect of fluvial islets along the Danube reach. Between 1864 and 2010 the number of islets slightly increased with the total area ranging from 21.19 kmp to 27.96 kmp. In the period studied, the shape turned from a rounded aspect to a more elongated one. Knowledge of the information on the shape of those landforms is relevant for river restoration strategies, nature conservations of islets and maintenance of the protected habitats.

Volume XV |

Classification, Typology and Distribution of Solification Rocks in Romania

Abstract: The present paper seeks to contribute to the better knowledge of the parental rocks of different soil types that are found in Romania, as well as their share in the country’s territory.
During its geological-geographical evolution, on Romania’s territory various geological (petrographic) formations have been formed, from crystalline rocks to loams, sands, fluvial and organic deposits. Because the types of rocks are numerous and their territorial distribution changes in narrower areas, the paper aims to group them according to their associating mode, genesis, as well as to their contribution to soil formation.
The paper introduces a new map of solification rocks in Romania, scale 1:1.000.000, which aims not only to their theoretical classification, but also to determine the surfaces occupied by each category, and their distribution on the country’s major relief units. In addition to the new map, achieved after the processing and updating of different cartographical materials using GIS techniques, information regarding the soil types formed on each category of parental rocks is provided.

Volume XV |

Morphological Analysis of Topolog Basin Fluvial Terraces: A Valleys System Evolution Approach

Abstract: The organisation of valleys network leads to the morphological identity of a territory, developing particular internal developmental models that take into account a number of parameters, such as the climatic, tectonic, eustatic and glacioeustatic ones, the local and regional basic levels or the local morphodynamics. Their highlighting is being reflected in the landscape by structural and quantitative differences resulted from the valley’s evolution up related to each terraces level. In that sense, a probative example is the Topolog’s basin which overlaps three morphostructural units having distinctive dynamics: the Făgăraş Mountains’ Group, the Argeş and Vâlcea Subcarpathians and the Cotmeana Piedmont. The analysis of the position, number, features and structure of the current fluvial terraces, of the way in which the hydrographic network was imposed in the landscape by its evolution enables the identification and tracking of some models with different characteristics on the three sections drained by the Topolog river. Therefore, in the mountain sectorthe valley’s evolution has imposed hydrographic disturbances, in the Subcarpathian one a deepening of the initialcourse and in the piedmont sector some changes through lateral dislocation determined by the amplitude of the elevation process and the thickness of the piedmontan deposits, concurrently with the existence of certain subsidence areas along the Olt river. The direct correlation between the structural features of terraces and the thickness of the deposits along the Topolog river wasaccomplished by an integrated interpretation of the data we have achieved from the electrical resistivity method (49 vertical electrical sounding) and geotechnical survey.