SLIDEFORNET: a web tool for assessing the effect of root reinforcement on shallow landslides

Protection forests are an important element in the integrated management of natural hazard risks, usually mentioned as “biological measures”. In fact, protection forests are recognised to play an important role in the mitigation of natural hazard risks in many mountainous regions. However, the integration of the protective effect of forests in regional/national management plans and political strategies is often hindered by difficulties with the quantification of those effects. One of the main reason is the lack of data and methods that allow accounting for the protective effect of forest in hazard analysis. In addition, the definition of forest target profiles in silvicultural guidelines are mostly based on scientifically founded forest ecological know-how, but not on quantitative knowledge of the interaction between forests and gravitational processes. In the case of rockfall, the recent scientific contribution in term of new experimental data and development of numerical tools has allowed a considerable improvement in the quantification
of protection forest effects, and it can be considered as good example for the quantification of protection forests function. In the case of erosion and shallow landslides, the lack of knowledge is due to : 1) the difficulty in synthesise the global effects of vegetation on the complex interaction of processes related to slope instabilities (hydrological & mechanical), 2) the lack of scientifically based information (e.g. data on root distribution of different tree species, studies on root reinforcement under compression). Nevertheless, ongoing research is contributing to better approach the quantification of some stabilisation mechanisms due to vegetation such as root reinforcement or evapo-transpiration (Stokes et al., 2014). In this paper we discuss in particular the possibility to quantify the effect of root reinforcement on slope stability. The objective of this paper is to introduce new concepts on root reinforcement mechanisms emerged due to recent studies and to present a new tool, SLIDEFOTNET, for the quantification of the stabilisation effect of root reinforcement on steep slopes.