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Geomorphology

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.

Volume XV |

Geomorphosites with touristic value in the central – southern part of the Parâng Mountains

Abstract: The aim of this study is to identify, assess and rank the geomorphosites with touristic potential from the central – southern part of the Parâng Mountains. The touristic assessment of geomorphosites was based on the method elaborated by J.P. Pralong in 2005, which was initially applied on two areas from the Alps. The touristic value of the geomorphological sites is the arithmetical mean result of four values (scenic, scientific, cultural and economic). For each value, points were scored, according to 4 – 6 criteria, highlighting, where necessary, the particularities generated by the studied area. The ranking of geomorphosites represents the base for their inclusion in promotional materials elaborated by authorities or private operators from the region. The promotion of landforms that have acquired a certain value represents, besides the promotion of cultural attractions, the starting point in the touristic development which the region aims at.

Volume XIV |

Snow avalanche tracks mapping within Bâlea glacial valley (the Făgăraș Mountains) using semi-automated detection methods

Abstract: Mapping of snow avalanche tracks based on topographic maps, aerophotos and field data to achieve inventories for the whole mountaineous areas in Romania is an important step in snow avalanche risk assessment and other related geomorphic processes. This requires experience and it is a time consuming process. In the absence of field data, the process of snow avalanche tracks mapping is influenced by the subjectivity of those who digitize.
Thus, we propose a semi-automated method for detection of snow avalanche tracks based mainly on geomorphometric parameters that can be extracted from the Digital Elevation Model (DEM) like slope gradient, plan and profile curvature, mean curvature, runoff.
In this study we used an object based analysis to detect snow avalanche tracks in central part of the Făgăraș Mts. This approach has two steps, segmentation and classification. First, we segmented the area based on plan curvature (which is the most important parameter that describes these snow avalanche tracks) in order to obtain objects. In the process of classification we added other conditions such as fuzzy function for slope gradient, thresholds for altitude and runoff and a shape index of objects. The results obtained were very close to the mapped tracks using digitizing techniques. The maps resulted from the classification were compared to the those resulted from digitizing in both number of objects and spatial agreement of the class of objects. There was a very good fit in case of the number of objects and total area of objects. The method could be improved if we apply on high resolution DEMs and also on more case studies with different topography and existing vector database.

Volume XIV |

Landscape metrics as a tool for landform pattern delineation. A case study on dune fields

Abstract: During the recent years, landform detection and mapping has been one of the most active fields of geomorphometry. However, there is still a need for quantitative work addressing the issue of classifying repeating landform types (MacMillan et al., 2004). The main issue in developing an accurate automatic classification algorithm of repetitive landform types is given by the difficulty to integrate contextual information within the analysis (Evans, 2012). Therefore, the motivation of the current approach is strongly related to the importance of context analysis in the field of specific geomorphometry. Introduced in landscape ecology to evaluate the spatial structure of a landscape, the concept of landscape metrics embraces a series of specific indicators for quantifying topological and contextual information. Thus, considering the fact that the assessment of topological and contextual attributes is not possible based on local, statistical and regional land-surface variables, the main objective of this study is to assess the applicability of landscape metrics for the delineation of landform patterns.
The quantification of landscape metrics involved the segmentation and classification of the following morphometric variables: elevation, profile curvature and local relief. Using an unsupervised method, the Iso Cluster Unsupervised Classification tool from ArcGIS10® software, a total of 24 classes have been used in order to fulfill the minimum requirement imposed by the concept of landscape metrics and further statistical analysis. In order to test the transferability degree of landscape metrics among different dune fields, a set of statistical analyses was carried out. The proposed methodology has been applied on freely available ASTER GDEM’s. This paper provides new prospects regarding the applicability of landscape metrics for the delineation of landform patterns.