The work should also include the cleaning of the drainage ditches that might be present at the base of the dry-stone wall, or the creation of new ones when needed to guarantee the drainage of excess water. Other structural measures include the removal of potentially www.selleckchem.com/products/rgfp966.html damaging vegetation that has begun to establish itself on the wall and the pruning of plant roots. Shrubs or bigger roots should not be completely removed from the wall, but only trimmed to avoid creating more instability on the wall. Furthermore, to mitigate erosion on the abandoned terraced fields, soil and water conservation practices should be implemented, such as subsurface drainage as

necessary for stability, maintenance of terrace walls in combination with increasing vegetation cover on the terrace,

and the re-vegetation with indigenous grass species on zones with concentrated flow to prevent gully erosion (Lesschen et al., 2008). All structural measures should be based on the idea that under optimum conditions, these find more engineering structures form a ‘hydraulic equilibrium’ state between the geomorphic settings and anthropogenic use (Brancucci and Paliaga, 2006 and Chemin and Varotto, 2008). This section presents some examples that aim to support the modelling of terraced slopes, and the analysis of the stability of retaining dry-stone walls. In particular, we tested the effectiveness of high-resolution topography derived from laser scanner technology (lidar). Many recent studies have proven the reliability of lidar, both aerial and terrestrial, in many disciplines concerned with Earth-surface representation and modelling (Heritage and Hetherington, 2007, Jones et al., 2007, Hilldale and Raff, 2008, Booth et al., 2009, Kasai et al., 2009, Notebaert et al., 2009, Cavalli and Tarolli, 2011, Pirotti et al., 2012, Carturan et al., 2013, Legleiter, 2012, Lin et al., 2013 and Tarolli, 2014). The first example

is an application of high-resolution topography derived from lidar in a vegetated PTK6 area in Liguria (North-West of Italy). Fig. 13 shows how it is possible to easily recognize the topographic signatures of terraces (yellow arrows in Fig. 13b), including those in areas obscured by vegetation (Fig. 13a), from a high-resolution lidar shaded relief map (Fig. 13b). The capability of lidar technology to derive a high-resolution (∼1 m) DTM from the bare ground data, by filtering vegetation from raw lidar data, underlines the effectiveness of this methodology in mapping abandoned and vegetated terraces. In the Lamole case study (Section 2), several terrace failures were mapped in the field, and they were generally related to wall bowing due to subsurface water pressure.