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Geomorphology

Volume XVI |

A web-map of the landscapes of Vitosha Mountain and the development of landscape science in Bulgaria

Abstract: On the first hand, the purpose of this article is to present the map and classification of the landscapes of Vitosha Mountain. On the other hand, it aims to present this map as an example and illustration in the context of traditionally applied approaches in Bulgaria in defining the landscape, as well as in researching and classifying the landscapes. There is also a brief overview of the development of land-scape science in Bulgaria.
The choice of the territory in study relates to the fact that Vitosha Mountain is a protected area, i.e. a Nature park declared in 1934, now part of the NATURA 2000 network.
The Vitosha Landscape Map is developed by using GIS tools and it is implemented as a web-map, which makes it much easier to access, examine and work with it, as com-pared to static maps.

Volume XVI |

The impact of the urban expansion on the Jiu floodplain. Case study –Craiova, Romania

Abstract: The urban expansion of any settlement implies changing natural environment and gradually transforming it into an anthropogenic one to assure the needs of the community. A first step in urban planning is to identify the changes that have been made, and this study reconstructs the anthropogenic changes induced to the Jiu floodplain in the last 150 years, through multi-temporal spatial comparisons, geomorphological characteristics and anthropological and environmental transformation indicators. The processing of historical cartographic materials and current satellite imagery highlights the dynamics of the wetlands and the built-up area in the Jiu floodplain between 1864 and 2017. The urban expansion required flood protection works that were carried out along the canals and lakes resulting from the drainage of the ponds and marshlands. On the course of the Jiu hydro-technical works of straightening, embankment and regularization were achieved, which led to the transformation of the course from a highly meandered one as it was in the second half of the 19th century into a sinuous one in 2017. The study is a useful tool in urban planning, by centralizing the changes in the floodplain, the anthropogenic works carried out and the changes of the Jiu course within the analyzed sector.

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.