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Geomorphology

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.

Volume XV |

A complex approach in the interdisciplinary field of karst geomorphology. The case study of Anina karst area (Banat Mountains, Romania)

Abstract: Karst regions are characterized by discontinuity and even by the lack of surface water drainage due to the fissured and porous rocks, but the rivers are often flowing in the underground. Our study area is represented by the Anina karst area, a karst region that is situated in the largest and most compact carbonate area in Romania, the Reșița – Moldova Nouă Synclinorium. This study aims to analyse a mature karst area using a complex approach in karst geomorphology. To achieve this assessment, we intended (i) to get an overall description of the morphology of the area using digital data and GIS methods; (ii) to obtain detailed data regarding cost evolution using geophysics, hydrogeology and speleology, and (iii) to correlate all the data to evaluate the karst terrain from the geomorphology perspective.
Our research is still in progress, and yet we have results that are leading to a complex approach in karst topography research from a geomorphological perspective, using different fields of study as geology, speleology, spontaneous potential as geophysical method and computer science (GIS). Based on our field measurements we were able to correlate those features that are extremely important in karst solution processes, as water circulation, underground conduits, slope, soil properties, water properties in order to have a better understanding regarding the actual landscape in the Anina karst area and also in order to develop hypotheses regarding the possible evolution of karst landforms in the studied territory.
Interdisciplinarity in karst topography studies is very important. Only by involving scientists, and techniques belonging to different scientific domains, we may understand in detail the karst topography. This complex approach is useful for stakeholders and local authorities in their feasibility studies and strategies for local development due to the fact that our study enriches the knowledge regarding karst environment “behaviour” in Anina region.

Volume XV |

Evaluation of land use/land cover classification accuracy using multi-resolution remote sensing images

Abstract: Timely and accurate land use/land cover (LULC) information is requisite for sustainable planning and management of natural resources. Remote sensing images are major information sources and they are widely used for mapping and monitoring various land features. Images from various sensors, with different spatial resolutions, are available; however, the selection of appropriate spatial resolution is an essential task to extract desired information from images. This paper presents the conclusions of the work related to LULC classification based on multi-resolution remote sensing images. Optical data collected by three different sensors (LISS IV with 5.8 m and Landsat 8-OLI with 30 m and AWiFS with 56 m spatial resolutions respectively) in 2013 are examined against the potential to correctly classify specific LULC classes. The classifications of images are performed using Maximum Likelihood Classifier (MLC). The results indicate that the overall accuracy and kappa coefficient of LISS IV with 5.8 m are higher than that of Landsat 8-OLI with 30 m and AWiFS with 56 m images. Understanding the role of spatial resolution in LULC classification accuracy will enable the appropriate interpretation of any classified images.