During the landslide emergency many kinds of data, even if preliminary, can help to better understand the complexity of the investigated phenomenon and to give a valid contribution to the successive damage valuation. The electrical resistivity tomography (ERT) method was applied for investigating the deep characteristics of a landslide body that occurred in March 2006 close to Potenza town in Basilicata region (southern Italy): the landslide slid on a road near some farmers’ houses which had to be evacuated. The information obtained by the application of this indirect technique appeared to be particularly useful for end users involved in the risk management. The high resolution of the 2D ERT technique allowed the detection of possible sliding surfaces and the characterization of high water content areas in which the increase of the saturation degree and of pore pressures could cause a weakening of the slopes and a reactivation of the movement. Due to the comparison between ERT results and stratigraphical data from boreholes carried out in the area it was possible to decide on the adoption of other evacuation decrees. 1. Introduction The investigated area is located in Basilicata region, one of the southern Italian areas more involved in heavy meteorological conditions [1]. On March 2006, the intense precipitations have increased the saturation degree and the pore pressures of the terrains. The snow blanket has made heavy the slope changing the equilibrium of the strengths involved in the stability of a slope. These climatic conditions have deteriorated the physical and mechanic characteristics of the terrains outcropping in the region. As consequence of all these alterations, the reactivation of many dormant landslides, which affected the slopes of the region in the past, occurred. The main typologies of reactivation have been earth-flow, translational, or rotational slides. The new slides have involved buildings and infrastructures on the slopes. The risk for people and assets needed the intervention of the end users involved in the risk management and, in particular, the inspection of Regional Department of Infrastructure and Civil Protection (RDICP). In many involved areas and for many families evacuation decrees have been issued in order to ensure the safety of the people and allow the damage valuation. The study of such complex phenomena required a multidisciplinary approach based on the integration of all the direct and indirect data acquired in the area. An important contribution has been provided by the geophysical data and, in particular, by
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