Studio delle caratteristiche morfoevolutive del fondovalle del F. Basento fra Pisticci e la foce, finalizzato all'ottimizzazione dell'intervento antropico

Abstract

An analysis is made of the evolutionary features of the Basento Plain landform in the stretch between Ferrandina Scalo and the sea, in context of the knowledge of the geomorphological and hydrological peculiarities of the whole catchment basin. The stretch in question lies in the south eastern portion of the Fossa bradanica where there are extensive outcrops of Plio-Pleistocene sedimentary deposits, represented mainly by blue-grey marly clays and, subordinately, sands and gravels. Between Ferrandina Scalo and Pisticci Scalo the Bradano is a braided river, while the reach between there and its mouth on the Ionian Sea is characterized by a meander belt. A detailed geomorphological examination, supported by air-photo interpretation (1953, 1973 and 1989 flights), has been made to ascertain the changes which have occurred on the plain in the last forty years. Knowledge of recent bed changes has been augmented by data derived from old maps. This has provided a picture of midifications over a hundred years or so. The principal hydrogeomorphological factors throughout the entire stretch studied can be correlated with the various fluvial trends identified. It ensues that there is substantial diversity in the relative stability conditions of the fluvial trends. More precisely, the potential instability within the meander belt can be tied in with the progressive increase in the sinuosity during the last hundred years. The in-depth hydrological study was made to highlight the main changes in use of the water resources available in the catchment, so as to establish possible relationships between man-made alterations and recent geomorphological conditions throughout the stretch concerned. It is also evident that during recent times man has been very active right up to the very banks of the river, modifying the original countryside by planting trees, growing crops and setting up industrial enterprises, once inexistent or at least located well away from the channel. On the basis of the factual picture acquired in this manner an evaluation has been made of the relationships between the recent variations in the natural geomorphological trends of the Basento in this reach, the direct and indirect upset of hydrodynamic parameters caused by man and the modifications in the landform of the flood-plain, triggered by human intervention. As the economic plan provides for a further increase in economic activities and for new hydraulic works throughout the catchment, various guidelines have been framed to optimize development.