Soil bio-engineering techniques for landslide risk mitigation in Italy: statistics from ISPRA's database "ReNDiS"

ReNDiS is a web-GIS open data developed by ISPRA as part of the technical-scientific support provided to the Italian Ministry of the Environment and Energy Security to monitor the implementation of hydrogeological risk mitigation measures and to manage the evaluation of funding requests from all Italian Regions, since 1999 [Gallozzi et al., 2020]. Information is organised starting from individual mitigation measures. Design phases of the projects, type of solutions adopted and accounting data are collected for all of them. Each measure is subdivided into lots (corresponding to a single project) and these lots may be composed of one or more types of works. The database implements also the types of works that can be recognized as soil bio-engineering techniques: from this detailed classification it is possible to estimate which measures implement some of them, either entirely or in combination with other ‘traditional’ works.  Among the surveyed measures, detailed and reliable technical information about the types of works and hazard mitigated is available for a large amount of them. Within these measures, the amounts of measures that include works for landslide risk mitigation were assessed. Among landslide risk mitigation, the percentage of the types of works that fall within soil bio-engineering category were evaluated too. Moreover, it is found that vegetation reinforcement is, to a large extent, combined with structures or reinforcements made of biodegradable materials such as wood, bio-mats, bio-nets and stones. The most adopted traditional engineering works include reinforced concrete piles and walls, cortical reinforcement through steel mesh, and drainage systems. Soil bio-engineering solutions are used to improve soil strength over time, thanks to root growth, and they are used to cover large areas, thus mitigating especially shallow landslides and erosion phenomena over large areas. Given the landscape, cultural, economic and sustainability interests involved, the monitoring of such bio-engineering solutions through the ReNDiS database is a fundamental tool for planning new landslide mitigation works throughout Italy, in order to reduce visual impact with the same efficiency.

References:

Gallozzi P.L. et al. (2020); ReNDiS 2020 La difesa del suolo in vent'anni di monitoraggio ISPRA sugli interventi per la mitigazione del rischio idrogeologico - Edizione 2020. ISPRA, Rapporti 328/20.