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Geomorphology

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.

Volume XIV |

Assessing flood inundation extent and landscape vulnerability to flood using geospatial technology: A study of Malda district of West Bengal, India

Abstract: Assessment of flood risk zonation and landscape vulnerability to flood are fundamental aspects in flood risk management. Landsat 8 Operational Land Imager (OLI) and ASTER DEM data were used to assess landscape vulnerability to flood inundation and flood risk in Malda district of West Bengal state, India. Flood inundation map was prepared on the basis of water and non-water pixels on images (before and during the flood event). Flood risk map was prepared using equal interval of separation based on elevation and inundated flooded area. Flood inundation map was overlaid on the pre-monsoon land use/land cover map to produce landscape vulnerability to flood. The results revealed that 19% area of the district was flooded during monsoon flood event in 2014 and the agricultural area was most affected land use, sharing 62% of the total flood affected area, followed by river bed (21%), built up (7%) and vegetation (5%). The flood risk map of the district shows that temporary river islands, sand banks along the Ganga river course lie in low flood plain and were considered under high risk zone. The flood plain alongside minor stream drainage in southern, north-western and in between them comes under medium flood risk zones. Flood risk is low in areas which are away from the rivers. Non flooded areas were identified in high lands of eastern region of the district. Landscape vulnerability map shows that the blocks located along the Ganga river namely Kaliachak I, Kaliachak II, Kaliachak III, Manikchak, Ratua I were highly vulnerable to flood. The study suggests that efforts should be made to remove the sediments for increasing the depth of river. Spurs and bed bars should be constructed to avoid great loss of prime agricultural land, property and lives of people.

Volume XIII |

Geomorphological Risk and Denudational Index (Land Erodability) in Karstic Terrain of Anina Mining Area (Banat Mountains, Romania)

Abstract: Anina Mining Area was defined by Vasile Sencu in 1977 as the area that is surrounding Anina town and may be exploited by mining activities.
The aim of this paper is to present two parameters regarding geomorphometry in Anina Mining Area, naming here Geomorphological Risk and Denudational Index (Land Erodability Index). These two morphometric parameters are obtained using geomorphological parameters that we obtained in previous works, as slope, hypsometry, drainage density, depth drainage and morphodynamic potential. The methodology to derive Geomorphological risk and Denudational index (Land Erodability Index) is based on GIS techniques.
The results we obtained point out that the study area of this paper is a region where parameters such as geomorphological risk and denudational index have small incidence. This fact is due to the large homogeneous areas from the standpoint of geology and land cover, but also as an effect of large surfaces with a planar aspect as karstic plateaus.
From the analysis of these two parameters we must conclude that Anina Mining Area represents a space with small surfaces which are prone to risks associated with geomorphological process and also with small areas where denudation may have high rates due to the large areas where vegetation is present and also due to large plateaus where the primary processes are related to karstification, and these ones are very slow processes.