Groundwater inspection in coastal aquifers using MT and AMT methods

M. DI MAURO;A. MANZELLA;RANIERI, GAETANO;DEIDDA, GIAN PIERO;A. CASAS

2005-01-01

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Abstract

In the framework of the SWIMED, Salt Water Intrusion European Project, the coastal aquifers of Muravera, south-western Sardinia, have been studied. Intensive agricultural and tourist activities have exploited these aquifers in the past. Since few years, a salt-water intrusion happens, mainly caused by a recurring lasting drought, by aquaculture system and by intensive rice growing. Geophysical studies performed in past in the same area showed deep geological structures and placed questions about 300 meters deep groundwater conditions. In Muravera plain Gravimetric, Seismic and TDEM Electromagnetic surveys have been carried out in the last years (Deidda et alii, 2000, Deidda et alii, 2003, Casas et alii, 2003). Those methods have shown an inadequacy in independent use to solve the delineation of aquifers. Furthermore, especially in the Muravera plane, because of climate, isolation and impervious field, an easy-exploiting and low-power-requiring method is needed. Hence, in the present work all the previous surveys’ data have been re-examined and integrated with an Audio Magnetotelluric survey along the same line surveyed, a Magnetotelluric sounding and with an electric tomography.