Cartografia tematica geologica, geomorfologica e vegetazionale nella valutazione di impatto ambientale. Analisi del progetto della circonvallazione di Mezzolombardo (TN) e del suo imbocco nella Val di Non

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Abstract

[automatically translated] The use of thematic maps within a Geographic Information System (SIT) led through a series of original procedures, impact assessment (EIA) had on certain environmental components from the possible construction of a new road layout in expressway between the town of Mezzolombardo (TN) and the entrance to the Val di Non near the locality Rocchetta. For the purposes of this analysis, we were made, through the detection of land, of the detail cards to 1: 5,000 scale geological, geo-morphological and vegetation directly inserted inside a SIT. The geological mapping takes into account not only the composition of the Mesozoic substrate present and the effective extension of the rocky outcrops, the spatial distribution of the Quaternary deposits in the area. Even as regards the geomorphological mapping have been used polygon type similar to those geological units, intended to have a characterization of the territory of the continuous type. For the classification of the slopes have been used, in addition, the use of cards of the slopes derived from digital terrain models. Using geological and geomorphological data collected, is one of the hazard map was also created for rockfall using the method of shadow cones, suitably adapted to the case study. The vegetation mapping was made with physiognomic-structural policies, through the use of phytosociological method proposed by the school of Zurich-Montpellier. The indexing of the papers was carried out through the construction of territorial units geological and geomorphological synthetic type, obtained from the intersection of geological units with those geomorphological. It 'was thus formed a card in which for each unit are formed by the following attributes: geology, geomorphology origin and specific slope. These basic units (sub-units) were then merged into homogeneous units of synthetic type on the basis of the main recognized morphodynamic systems in the area. The allocation of environmental quality values to those units was carried out using the method of Rivas et al. (1995) appropriately revised and standardized. The map of vegetation was directly indexed taking into account an environmental quality value based on the ability to effectively hold their ground on the homeostasis capacity and structural stability of different types of vegetation. The two specific cards of geological and geomorphological and vegetation environmental value were then crossed to obtain a final paper of the environmental value. The environmental impact assessment procedure is based on the creation of an extension of 60 m buffer along two alternative paths from among the most probable paths and an overlapping area of the buffer to the environmental value cards and danger. In this way it was possible to evaluate in a quantitative way the direct loss of territory characterized by a given environmental value and the exposure to danger of falling boulders of each of the two alternatives, allowing a direct comparison between the two paths. The procedures in this study, as well as providing a well-defined conceptual framework for the EIA, provide quantitative information that can be used later in systems analysis and multi-criteria in decision support systems.
Original languageItalian
Pages (from-to)159-186
Number of pages27
JournalQUADERNI DI GEOLOGIA APPLICATA
Volume1 (2003)
Publication statusPublished - 2004

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