Decision makers need an evidence base in order to endorse expenditure on landslide risk reduction and adopt a proactive ex ante policy approach. A typical MoSSaiC project that tackles the root causes of landslide hazard will have measurable short-term outputs and longer-term outcomes
We emphasise the need to identify evidence of longer-term benefits of landslide risk reduction in communities—the actual reduction in the hazard, and the direct and indirect benefits (financial and social). The delivery of physical landslide risk reduction measures provides the opportunity to observe the benefits in terms of potentially avoided landslide occurrence and losses. This form of evidence is counter-factual and often anecdotal, since it is not know what would have happened if the physical measures had not been in place. However, it is still a powerful means of demonstrating the benefits of the intervention. Slope stability software can provide a means for quantifying the reduction in the frequency or magnitude of landslides. These model predictions can then be related to the value of the losses avoided (a project benefit) and compared with project costs. Less-tangible social benefits and changes in slope management practice should also be captured.