The recognition and identification of debris flow hazards for proposed development sites in New Zealand

This paper discusses how debris flows, a commonly occurring natural hazard in mountainous regions of New Zealand, may be recognised and identified from field and desk studies for sites that are being considered for development. Use is made of a particular case study from the Southern Alps in which the previous occurrence of debris flows was seen to be a possibility from an initial site inspection. The paper highlights that a combination of simple tools and techniques, from digging trial pits to examination of historical photos, may enable a reasonably detailed picture to be drawn regarding the potential debris flow hazard at a site, despite the relatively poor records that are available in many remote areas of New Zealand.