The geology of Dunedin, New Zealand, and the management of geological hazards

Abstract

The city of Dunedin is located on the remains of a Miocene volcanic eruptive centre, which is underlain by Tertiary marine sediments and Late Cretaceous quartz gravel, sand and clay with some coal seams. These in turn rest on a basement of Jurassic schist. The geology and topography pose a number of geological hazards that must be considered in urban development. These include landslide, mine subsidence, ground shaking amplification and liquefaction, coastal erosion and tsunami. A number of research, policy and planning initiatives have been undertaken to assess and mitigate the effects of these hazards. A GIS-based Hazard Information System (for a part of the city) was developed to assist in identifying and mitigating hazards. Under legislation the Dunedin City Council (DCC) is obliged to keep a register of known hazards. In addition, a Lifelines project has been undertaken to identify hazards and related risks to emergency and utility services. These studies may be used by asset managers to prioritise mitigation measures for critical facilities as well as to avoid hazards. The DCC district plan includes policies to gather and maintain hazard information, encourage research into hazards, and control activities in areas that might be affected by hazards. © 2002 Elsevier Science Ltd and INQUA. All rights reserved.