GNGTS 2013 - Atti del 32° Convegno Nazionale

Mastrolorenzo G., Palladino D., Vecchio G. & Taddeucci J.; (2002): The 472 AD Pollena eruption at Somma-Vesuvius, Italy and its environmental impact at the end of Roman Empire. Journ. of Volcanol. and Geoth. Res., 113 : pp. 19-36. Orsi G., De Vita S., Di Vito M., Isaia R., Nave R. & Heiken G.; (2002): Facing volcanic and related hazard in the Neapolitain area. In: Heiken G., Fakundiny R. and Sutter J. (Eds.) Earth Sciences in the city. American Geophysical Union Spec. Publ., Washington, pp. 121-170. Paoletti V., Fedi M., Florio G., Supper R. & Rapolla A.; (2004): The new integrated aeromagnetic map of the Phlegrean Fields volcano and surrounding areas. Annals of Geophysics, 47 (5) , pp. 1569-1580. Paoletti V., Secomandi M., Fedi M., Florio G. & Rapolla A.; (2005): The integration of magnetic data in the Neapolitain volcanic district. Geosphere, 1 (2) : pp. 85-96. Pescatore T., Diplomatico G., Senatore M.R., Tramutoli M., Mirabile L.; (1984): Contributi allo studio del Golfo di Pozzuoli: aspetti stratigrafici e strutturali. Memorie della Società Geologica Italiana, 27 : 133-149. Rosi M. and Sbrana A.; (1987): Phlegrean Fields. Quaderni De La Ricerca Scientifica, CNR, Italy. Saccorotti G., Ventura G. & Vilardo G.; (2002): Seismic swarms related to diffusive processes: the case of Somma- Vesuvius volcano, Italy. Geophysics, 67 : pp. 199-203. Santacroce R:, (1987): Somma-Vesuvius. Quaderni De La Ricerca Scientifica, CNR, Italy. Secomandi M., Paoletti V., Aiello G., Fedi M., Marsella E., Ruggieri S., D’Argenio B. & Rapolla A.; (2003): Analysis of the magnetic anomaly field of the volcanic district of the Naples Bay. Marine Geophysical Researches, 24 : pp. 207-221. Scarpa R., Tronca R., Bianco F. & Del Pezzo E. (2002): High resolution velocity structure beneath Mount Vesuvius from seismic array data. Geophysical Research Letters, 29: pp. 204-219. Todesco M., Neri A., Esposti Ongaro T., Papale P., Macedonio G. & Santacroce R. (2002): Pyroclastic flow hazard at Vesuvius from numerical modelling I. Large scale dynamics. Bulletin of Volcanology, 64 : pp. 155-177. Time Lapse 3D Electrical tomography for soil-plant dynamics interactions J. Boaga, M. Rossi, G. Cassiani Dipartimento di Geoscienze, Università degli Studi di Padova, Italy Introduction. We are fronting an increasing global demand of optimization in terms of land use and water management, both for civil exploitation and agriculture. This means a growing demanding in quality and quantity calls for sustainable management of water catchments and better understanding of water and solute movement in the critical vadose zone. Non invasive geophysical techniques can play a key role in the hydrological investigation of the near surface, as they provide spatially extensive imaging that complement the more traditional hydrological point measurements (e.g. Vereecken et al. , 2006). Between geophysical techniques, time-lapse Electrical Resistivity Tomography (ERT) was recently adopted in several studies to estimate, albeit indirectly, changes in moisture content (e.g. Binley et al. 2002, Strobbia and Cassiani, 2007) and solute concentration (Cassiani et al. , 2006). In the framework of plants/subsoil interactions ERT techniques were recently downscaled to image the root zone geometry (Jayawickreme et al. , 2008; Muller et al. , 2003; Werban et al. , 2008; al Hagrey and Petersen, 2011; Jarvaux et al. , 2008). These applications pose new interdisciplinary high demanding challenges from ecohydrology to geoecohydrology (Eagleson, 2002). In this framework we are applying hydrogeophysical methodologies to several sites of different climatic zones in terms of upper soil hydrology, downscaling non invasive geophysical techniques to the upper subsoil biosphere interactions. The aim of this work was to apply ERT techniques to the monitoring of plant root zone for 2 field cases. For this specific purpose it is necessary a 3D ERT apparatus with very detailed resolution capabilities and, due to the small target, extremely attention to be non invasive. In order to get a 3D resistivity imaging under a plant, we need small inter-electrodes spacing both in depth buried electrodes and surface ones. We need also the lowest possible resistance contact with soil and the minimum site disturbance together with reasonable efficiency in time to perform time-lapse measurements. For all these reasons we designed 1 inch PVC boreholes totally internal wired, equipped with 12 round steel electrodes each with 0.1m spacing. 91 GNGTS 2013 S essione 3.2