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 ground is a natural grand system; it is composed of myriad constituents that aggregate to form several geologic and biogenic systems. These systems operate independently and interplay harmoniously via important networked structures over multiple spatial and temporal scales. This paper presents arguments and derivations couched by the authors, to first give a better understanding of these intertwined networked structures, and then to give an insight of why and how these can be imitated to develop a new generation of nature-symbiotic ground engineering techniques. The paper draws on numerous recent advances made by the authors, and others, in imitating forms (e.g. synthetic fibres that imitate plant roots), materials (e.g. living composite materials, or living soil that imitate fungi and microbes), generative processes (e.g. managed decomposition of construction rubble to mimic weathering of aragonites to calcites), and functions (e.g. recreating the self-healing, selfproducing, and self-forming capacity of natural systems). Advances are reported in three categories of Materials, Models, and Methods (3Ms). A novel value-based appraisal tool is also presented, providing a means to vet the effectiveness of 3Ms as standalone units or in combinations.

Deep slope movements and, eventually, slope failure, have been often interpreted to be due to slope-vegetation-atmosphere interaction on slopes formed of clayey materials in the Italian Southern-Eastern Apennines, as reported in the literature. Such slopes are generally formed of flysch, within which clay is the main lithotype. Such clays are characterized by a disturbed meso-fabric, as an effect of the intense tectonics. The paper presents the results of coupled hydromechanical numerical analyses of the slope-vegetation-atmosphere interaction for a clay slope representative for the geomechanical scenario where such climate-induced deep slope movements have been repeatedly recorded. In the analyses, different model initialization procedures and parameter values were adopted. The comparison of the numerical results with the site data is aimed at assessing the effects of the soil-vegetation-atmosphere interaction taking place in the top strata of the slope, on the stress-strain conditions across the whole slope, and on the slope stability. The comparison between the numerical results of the analyses carried out entailing different initialization stages are intended to evaluate the influence of such a stage on the model predictions. It is found that only when the slope model initialization accounts for the slope loading history, developed over geological time, the numerical predictions get close to the site observations. In such case, the numerical results confirm that deep movements consequent to progressive failure may take place in clay slopes due to the slope-vegetation-atmosphere interaction.

<p>The soil-vegetation-atmosphere interaction is becoming more and more the subject of intense scientific research, motivated by the wish of using smart vegetation implants as sustainable mitigation measure for erosive phenomena and slope instability processes. <br>The use of novel naturalistic interventions making use of vegetation has been already proven to be successful in the reduction of erosion along sloping grounds, or in increasing the stability of the shallow covers of slopes, whereas the success of vegetation as slope stabilization measure still needs to be scientifically proven for slopes location of deep landslides, whose current activity is climate-induced, as frequent in the south-eastern Apennines. Recently, though, peculiar natural perennial grass species, which develop deep root systems, have been found to grow in the semi-arid climate characterizing the south-eastern Apennines and to determine a strong transpirative flow. Therefore, their peculiar leaf architecture, their crop density, combined with their perennial status and transpiration capacity, make such grass species suitable for the reduction of the net infiltration rates, equal to the difference between the rainfall rate and the sum of the runoff plus the evapotranspiration rate. As such, the grass species here of reference have been selected as vegetation measure intended to determine a reduction of the piezometric levels in the slope down to large depths, in order to increase the stability of deep landslide bodies. <br>At this stage, only preliminary field data representing the interaction of clayey soils with the above cited vegetation species are available. These have been logged within a full scale in-situ test site, where the deep-rooted crop spices have been seeded and farmed. The test site (approximatively 2000 m<sup>2</sup>) has been set up in the toe area of the climate-induced Pisciolo landslide, in the eastern sector of the Southern Apennines.<br>The impact of the vegetation on the hydro-mechanical state of the soil is examined in terms of the spatial and temporal variation of the soil water content, suction an pore water pressure from ground level down to depth, both within the vegetated test site and outside it, where only spare wild vegetation occur, in order to assess the effects of the implant of the selected vegetation. The soil water contents, suctions and pore water pressures have been also analyzed taking into account of the climatic actions, monitored by means of a meteorological station. </p>