Engineers Australia

Evaluation of the Tasmanian North-West Coast landslide map series against the AGS 2007 Landslide Zoning Guideline

Colin Mazengarb and Michael D. Stevenson

Abstract

This paper documents an assessment of the recently produced Tasmanian Landslide Map Series in Tasmania’s North-west Coast region against the AGS 2007 Landslide Zoning Guideline and Commentary. In addition, comments are made on the Guideline and Commentary from the perspective of a practitioner using these documents.

Mineral Resources Tasmania (MRT) welcomes the introduction of the Guideline, and its Commentary, and have striven to adopt them as far as practically possible within the constraints of our project. The Guideline and Commentary provide a conceptual architecture and standard terminology for the practice which has been largely accepted by MRT.

Using the Guideline’s criteria we have classified the MRT maps as suitable for local and regional development because of its medium scale. Our landslide inventory is at the intermediate zoning level and our susceptibility mapping at the preliminary zoning level, which confirms the maps general intention and suitability for regional zoning purposes. MRT has used a combination of largely heuristic and deterministic transforms to create its susceptibility maps. The combined approach is more complex than the conceptual descriptions contained in the Guideline but this is in keeping with other published examples.

The experience gained by the production of regional scale maps at MRT enables the authors to comment on the usefulness of the Guideline and Commentary. Landslide zoning is a challenging exercise that requires considerable effort, skills and resources to put into practice. From the perspective of practitioners, it is the observation of the authors that some aims, realistically, may not be attainable within the constraints of most regional projects. Furthermore, the science underpinning the practice of landslide zoning is rapidly evolving and this requires the practitioner not to rely on the Guideline alone but to keep abreast of developments that are typically only published in the international literature.