The activity of deep landslides in slopes formed of clayey turbidites has been observed to be connected to the climatic regime in the Mediterranean, based on field data and phenomenological interpretations. With the aim of investigating this connection, the effects of the soil–vegetation–atmosphere interaction on the piezometric regime were investigated by means of hydraulic finite-element analyses of the transient seepage across a prototype clayey slope. The ground surface condition was defined accounting for rainfall and evapotranspiration flux, estimated through the United Nations' Food and Agriculture Organization Penman–Monteith approach. The predicted excursions of the piezometric head within the slope over time were found to agree with field observations. The predicted piezometric profiles were investigated to evaluate the infiltration processes during the year and show how these bring about seasonal piezometric excursions. The results of the hydraulic analyses were then input into limit equilibrium analyses to assess the impact of the slope–vegetation–atmosphere interaction on the stability of landslide bodies of different depths. The results show how such impact depends on the stratigraphy of the slope. Furthermore, the variability of the climatic precursor of landsliding with landslide depth was characterised to guide the design of early warning systems for mitigation purposes.

The paper presents the results of the analysis of the geo-chemo-mechanical data gathered through an innovative multidisciplinary investigation campaign in the Mar Piccolo basin, a heavily polluted marine bay aside the town of Taranto (Southern Italy). The basin is part of an area declared at high environmental risk by the Italian government. The cutting-edge approach to the environmental characterization of the site was promoted by the Special Commissioner for urgent measures of reclamation, environmental improvements and redevelopment of Taranto and involved experts from several research fields, who cooperated to gather a new insight into the origin, distribution, mobility and fate of the contaminants within the basin. The investigation campaign was designed to implement advanced research methodologies and testing strategies. Differently from traditional investigation campaigns, aimed solely at the assessment of the contamination state within sediments lying in the top layers, the new campaign provided an interpretation of the geo-chemo-mechanical properties and state of the sediments forming the deposit at the seafloor. The integrated, multidisciplinary and holistic approach, that considered geotechnical engineering, electrical and electronical engineering, geological, sedimentological, mineralogical, hydraulic engineering, hydrological, chemical, geochemical, biological fields, supported a comprehensive understanding of the influence of the contamination on the hydro-mechanical properties of the sediments, which need to be accounted for in the selection and design of the risk mitigation measures. The findings of the research represent the input ingredients of the conceptual model of the site, premise to model the evolutionary contamination scenarios within the basin, of guidance for the environmental risk management. The study testifies the importance of the cooperative approach among researchers of different fields to fulfil the interpretation of complex polluted eco-systems.

The paper reports the results of a slope-atmosphere interaction analysis performed with reference to geo-hydro-mechanical conditions typically observed on the Southern Apennines (Italy). The aim of the analysis is to gain some understanding in the characterisation of climatic variables employed to identify instability thresholds in clay slopes. A seepage analysis was undertaken first, showing that Mediterranean climates can produce significant pore-pressure changes also at depths not usually considered to be affected by atmospheric conditions. Based on the results of the seepage analysis, limit equilibrium analyses were carried out for a 5 m and a 20 m deep landslide, confirming that also deep movements in clay slopes can be related to slope-atmosphere interaction. The characterisation of climatic variables aimed at identifying instability thresholds is finally discussed based on the analyses reported in the paper. The results show that net rainfall cumulated over 2 and 6 months represent suitable climatic variables for the 5 m and the 20 m deep landslide, respectively. These findings suggest that the stability of a clay slope, when referred to shallow movements, is likely to depend on the rainfall infiltrating over a few weeks at least. When deep movements are considered, the stability seems to depend more on the rainfall gradually infiltrating during the most rainy seasons.