NUOVE TECNOLOGIE SPAZIALI PER LA GESTIONE DEL RISCHIO IDRAULICO NELLA PIANIFICAZIONE TERRITORIALE

The aim of the study is to show, how and how much, urbanization and soil sealing can change the hydraulic performance of a given geomorphology. The analysis area includes the territory of the ex Consortium for Land Reclamation Medio Astico Bacchiglione; a specific test was performed to Municipality of Thiene (Province of Vicenza). Thanks to a dedicated spatial algorithm developed with ArcGis it was possible to correlate, per pattern of land use, the runoff coefficients at the digital terrain model (DTM). The implementation of the functions of direction and accumulation (hydrology tools), has allowed to study the behaviour of the superficial runoff and to evaluate the hydrological impacts per use change, of two reference periods (1954 and 2006). The test generates the risk mapping. Areas at different vulnerability and exposure are identified with tool focal statistics. Referred to them are the spatial planning strategies on watershed scale. The algorithm in GIS environment allows to manage flood risk with multiscale and multitemporal analysis of the dynamics of land use, and to estimate the incremental levels of soil sealing and cumulative impacts. Hazard and risk are managed with a complete overview of the problem; it allows to check, in time, the uses at high impact and the health risk. The obtained results support the urban regeneration policies and the territorial development.