Geographical studies and environment protection research
Volume X | Issue 2
Human-Induced Environmental Changes and Floodplain Restoration Necessity along the Danube, on the Drobeta-Turnu Severin – Bechet Sector
Abstract: The present paper aims at analysing the human-induced transformations that took place in the Drobeta-Turnu Severin – Bechet sector of the Danube Floodplain during the last two centuries. The research started from the need to obtain a real and comprehensive database concerning the extension, the nature and the characteristics of the topographic-hydrographical, edaphic and biologic structures appeared or modified under human influence, their relation with the changes occurred at the level of the land use and their present functionality. Special attention was paid to the latter transformations occurred after 1989. The primary types of topographical and hydrographical changes resulted from the geomorphic human activity in the Danube Floodplain are analysed in relation with the land use within this unit. The analysis of the environmental transformations in the floodplain sector started from cartographic and statistical materials that are relevant for the 19th-21st centuries. For the post-communist period, the valorisation of the Corine Land Cover database allowed for a more detailed analysis of the land use dynamics. The data thus obtained was checked and updated with field observations and measurements, which are mandatory given the fact that the cartographic database shows deficiencies and it is partially outdated.
Volume X | Issue 2
The Dynamics of Forest Areas in the Vâlsan Basin
Abstract: This case study refers to forest area dynamics within the Vâlsan Basin, situated between his affluents: Mierlei Valley and Bunești Valley in 1904-2004 period. The dynamics was shown by maps on a temporal scale especially in reference years as 1904, 1973, 1981, 1994, 2004. Forest cover from our study area has been decreased substantially because of the impact of human activities. We can conclude at the end of our paper that forest ecosystems had lost the natural equllibrium, and barely can realize the protective and hydrological function, in the context of declaring our study a natural reserve.
Volume X | Issue 1
Floodplains – Links between Countries and Landscapes
Abstract: The primary function of floodplains remains to be to ensure the safe passage of flood waves. As flood control problems are serious along some river sections, this also requires international cooperation. In landscape ecology, floodplains perform two related functions: they are riparian buffer zones (vital for maintaining river water quality) on the one hand and ecological corridors (ensuring connectivity and high biodiversity) on the other. Floodplain wetlands play an important part of the ecological integrity of riverine ecosystems as they fundamentally influence the ecological status of adjacent water bodies. It is all the more important since along most of its length the Danube crosses densely inhabited areas with intensive agriculture, large-scale industries and well-developed communication networks. Consequently, environmental pressure on the active and protected floodplains is of considerable extent and sharp conflicts arise between different land use types. Land use types promoting the fulfilment of the riparian buffer zone function must have priority. Unfortunately, only restricted sections of the Danubian floodplain are retained in seminatural conditions. In the Danube catchment 80% of the former wetlands are now disconnected and cannot fulfil their nature conservation role. The national NATURA 2000 networks are so much dependent on seminatural riparian ecosystems that they cannot be efficient without floodplain restoration measures. Predictable climate change tendencies (increasing drought liability) are also a threat to the survival of floodplains as ecological corridors. Remediation efforts are necessary along extensive floodplain sections and better connectivity is identified as an important target. According to the Danube River Basin District Management Plan (ICPDR 2009, p. 76):”The ICPDR’s basin-wide vision is that floodplains/wetlands in the entire DRBD are re-connected and restored. The integrated function of these riverine systems ensures the development of self-sustaining aquatic populations, flood protection and reduction of pollution in the DRBD”.
Volume X | Issue 1
Geohazard Assessment in the Eastern Serbia
Abstract: The territory of eastern Serbia is characterized by a variety of igneous, sedimentary and metamorphic rocks formed through different paleogeographic developments. As a result of varied natural conditions, the region is vulnerable to various geohazards, such as earthquake, landslide, excessive erosion, flood, rockfall, cave collapse and subsidence. The occurrence of any geohazard depends on the intensity of the process causing it. An assessment of each type of hazard or combination of all hazards is necessary for this region of Serbia which accommodates major power-generation, industrial and mining facilities and has rich mineral resources. Depopulation of eastern Serbia reduces the ability of local communities to invest in the hazard control works. This assessment of the geohazards begins with the reference to the available seismic maps and proceeds with the research in the landslide, potential flood and excessive erosion hazards, then rockfall and rock collapse. Research results suffice to prepare a generalized geohazard map of eastern Serbia showing areas vulnerable to particular natural hazards and to estimate a total area endangered by hazardous processes. The purpose of this work is to locate and classify areas of potential hazards on which future protective actions may be based.
Volume X | Issue 1
Application of Object Based Image Analysis for Glacial Cirques Detection. Case Study: The Ţarcu Mountains (Southern Carpathians)
Abstract: Geomorphologic mapping is an important fact in many research studies and the traditional methods are time consuming and expensive. This paper aims to develop a semi-automated rule-based method for the detection of glacial cirques for a test area located in the Ţarcu Mountains (Southern Carpathians) in an object-oriented approach. In this study we have established the morphometric characteristics of the glacial cirques developed in a particularly geomorphologic context at the edge of planation surfaces, using a 10 m horizontal resolution DEM (Digital Elevation Model). The parameters extracted from DEM (i.e. curvature) were further used in segmentation and classification process. Also, other factors were introduced in the rule set, as the context regarding neighboring objects like planation surfaces to the target class. The most important factor in segmentation was the curvature and to choose an appropriate scale factor we have used the available ESP (Estimation of Scale Parameter) tool. The results achieved were very close to the field reality, except for some areas where there are large negative landforms such as gullies and torrents, which were identified as objects belonging to glacial cirques class and also some roches moutonnées with high positive curvature values, objects that could be filtered manually by the user based on previous field knowledge and ancillary data such as orthophotoplans and the geomorphologic map of glacial relief in the Ţarcu Mountains. For further research, we intend to identify the characteristic thresholds for morphometric parameters that can be integrated in a set of rules in order to detect and classify other type of landforms in the alpine domain of the Ţarcu Mountains.