Debris-flow risk-to-life: Upper-bound preliminary screening

Where the potential for future debris-flow occurrence is unrecognised, developments can be unknowingly exposed to impact, with corresponding risks lives. Debris-flow modelling unsuited routine local office use, so a simple screening procedure proposed enable officials identify locations where debris flow risk-to-life may unacceptable, and prioritise expert risk analysis are most urgently required risk-management decision-making . This calculates catchment Melton ratio R from topographic data, uses linear upper bound of field data relating annual probability occurrence, matches model-based Matata, New Zealand. Our suggest that any development flows will require detailed assessment ensure does not exceed acceptable levels.