Definizione di strategie sostenibili per la gestione di bacini idrografici in aree semiaride

The present study focuses on defining a methodology to assess standards and objectives for the protection, preservation and improvement of environmental quality in semi-arid river basins, as well as for sustainable use of natural resources by way of tailored measures, complying with the scopes of the peculiar environmental regulations. To this end, the Candelaro river basin was taken as a pilot case and it was crucial to acquire on-depth hydrological knowledge, including the anthropogenic pressures on surface water bodies and their interaction with groundwater and water-dependent surrounding habitats. Therefore, both the assessment of standards and objectives, and the definition of remediation measures are the outcome of ecological, hydrological and pressure-state analyses developed within the project. The reported initial analysis of the context outlines the present situation and the hydrological characteristics of the river basin in particular. The ultimate objective of this part is to assess the environmental state of the river basin and its major water bodies. For the characterization of the environmental state it was necessary to define quality elements for monitoring surface and underground water bodies according to the European Water Framework Directive, as well as to identify major eco-systems of the river basin equally related to the hydrological dynamics of the water courses. In particular, the major ecosystems were identified by jointly analysing the morphological elements through the digital elevation model, colour orthophotos for the classification of riparian vegetation and river mouth wetland. All of the above was validated through field surveys. In the analysis of major ecosystems, the riparian ecosystems related to water courses were of special interest in that they create true ecological corridors that interrupt the absolute uniformity of the agricultural landscape of Capitanata. To this end, different survey methods of the ecological state of surface water bodies were considered, and CARAVAGGIO method was retained as the most adequate to the hydrological and habitat characteristics of surface water bodies of the Mediterranean area. The presence of flowing water is certainly the major element for the survival of the riparian habitat, so that one of the elements of context analysis was the identification of an integrated conceptual model for the representation of the hydrological processes in the Candelaro river basin. In our working methodology, the initial analysis was followed by a diagnosis of the ecological state of water courses and the main pressures on water bodies and the territory. Attention was focused on water courses and riparian strips, on wetlands located in the vicinity of the drainage network and, in particular, of the surveyed sites identified along the drainage network and such to be representative of a wide-ranging ecological quality. For the purposes of the analysis, the river types present in the river basin were classified and the reference conditions from which the quality state had to be measured were identified. Ecological quality assessments, as specified in the Legislative Decree 152/06, were made by comparing the EBI method, reported in the Legislative Decree, with other metrics (Intercalibration Common Metrics, ICMs) better complying with the Directive 2000/60/EC, these being more efficient in describing the quality gradients in the Mediterranean areas. Ecological quality assessment is completed with the diagnosis of the pressures that cause water bodies degradation, the ecological state being the representation of the natural and anthropogenic interactions that characterize aquatic habitats. In the case at issue, pressures are mostly attributable to the intensive agricultural