Large tracts of land throughout Tasmania are subject to slope instability and about 75 houses are known to have been destroyed by landslides, or demolished due to extensive damage, since the 1950s. Fortunately no loss of life has occurred in this time but such events are highly traumatic to those directly affected and the financial cost to individuals and the State runs into many millions of dollars. Disasters of this type can be avoided when ground conditions are understood before construction proceeds.
Landslides are a type of natural hazard that can be studied in order to understand their distribution, frequency of movement, triggering conditions and likely effects. By properly understanding landslide hazards it is often possible to minimise the effects on engineered structures (e.g. houses and roads) and the community. For example, landslide susceptibility maps produced by MRT can be used by town planners to avoid unstable areas when new subdivisions are being proposed.
MRT undertakes several activities with respect to landslides including regional mapping, administration of declared (or proclaimed) Landslip Areas and monitoring of a small number of 'problematic' Landslides. MRT does not undertake site-specific investigations for individuals. Those wishing to seek professional advice on land stability matters are recommended to contact either their local council or an engineering geologist or geotechnical engineer with the necessary experience in landslide risk management practice. Such persons are listed in the Yellow Pages under Geologists or Geotechnical Engineers. MRT supports the adoption of the 2007 Australian Geomechanics Society Landslide Risk Management Guidelines as representing best practice for the geotechnical community. These guidelines also provide information useful for regulators and the general public and can be downloaded from the 'Resources (Public Resources)' section of the Australian Geomechanics Society website.
For prospective homeowners it is important to realise that in most cases insurance companies in Australia do not provide cover for landslide damage, nor will the Tasmanian Government pay compensation to property owners as in the past, so the potential financial consequences to those affected by landslides may be significant. Therefore, getting advice from a qualified geotechnical professional before you buy is the best form of insurance available.
An overview of Tasmanian landslides and the risks they pose is provided in the MRT publication Tasmanian Landslide Map Series: User guide and technical methodology.
Brochures are also available for download.
For those wanting a more global overview of landslides there is a vast amount of landslide information on the internet. Some sites we recommend are Geoscience Australia and the United States Geological Survey.