摘要：Landslides constitute a hazard to life and infrastructure and their risk ismitigated primarily by reducing exposure. This requires information onlandslide hazard on a scale that can enable informed decisions. Suchinformation is often unavailable to, or not easily interpreted by, those whomight need it most (e.g. householders, local governments and non-governmental organisations). Toaddress this shortcoming, we develop simple rules to minimise exposure tocoseismic landslide hazard that are understandable, communicable andmemorable, and that require no prior knowledge, skills or equipment toapply. We examine rules based on two common metrics of landslide hazard,(1) local slope and (2) upslope contributing area as a proxy for hillslope locationrelative to rivers or ridge crests. In addition, we introduce and test twonew metrics: the maximum angle to the skyline and the hazard area, definedas the upslope area with slope >40∘ from whichlandslide debris can reach a location without passing over a slope of<10∘. We then test the skill with which each metric canidentify landslide hazard – defined as the probability of being hit by alandslide – using inventories of landslides triggered by six earthquakesthat occurred between 1993 and 2015. We find that the maximum skyline angleand hazard area provide the most skilful predictions, and these results formthe basis for two simple rules: “minimise your maximum angle to theskyline” and “avoid steep (>10∘) channels with many steep(>40∘) areas that are upslope”. Because local slopealone is also a skilful predictor of landslide hazard, we can formulate athird rule as “minimise the angle of the slope under your feet, especially onsteep hillsides, but not at the expense of increasing skyline angle orhazard area”. In contrast, the upslope contributing area has a weaker and morecomplex relationship to hazard than the other predictors. Our simple rulescomplement but do not replace detailed site-specific investigation: theycan be used for initial estimations of landslide hazard or to guidedecision-making in the absence of any other information.
