Abstract It is imperative today to make geoheritage conservation an essential part of all environmental standards and operational procedures. This is because geoheritage conservation secures the preservation of in situ geoheritage elements especially in urban environments such as Auckland. Geoheritage in Auckland is strongly associated with both indigenous culture and textbook geology of monogenetic volcanism, and it can play an important role in hazard forecasting and risk mitigation. To date, there has been a lack of policy or any planning tools based explicitly on the current geopreservation inventory. Here, we present an approach to support policy making informed by a spatial multi-criteria analysis that has long been used in environmental decision-making, supported by multi-layer mapping. A systematic literature review was undertaken to define the most accepted assessment criteria used in geoheritage evaluation. We identified six criteria for the base spatial layers of our analysis, highlighting the most suitable areas for geoheritage conservation. For cultural conservation, we used available archaeological shape files, indigenous land ownership data and elevation data (the volcanic cones had multiple roles in the life of first settlers, the ancestors of the Māori). Geographic Information Systems (GIS) multi-objective land use planning is an effective procedure for achieving complex planning and preservation objectives. It allows for outcomes based on quality data and sound analysis while minimizing compromise and conflict between geoheritage, social and cultural values.

Abstract For New Zealand, a country straddling the Pacific ‘Ring of Fire’, effective mitigation of the risks posed by tsunamis is an urgent priority. Mitigation measures include evacuation mapping, land-use planning and engineering of tsunami resilient buildings and infrastructure; but for these to be effective, a quantitative estimate of the tsunami hazard is needed. For this purpose we present the New Zealand Probabilistic Tsunami Hazard Model (NZPTHM). The model uses a Monte Carlo method for sampling from the geophysical parameters that constrain the magnitude–frequency distributions of the earthquake sources that can cause tsunamis affecting New Zealand. The sampled parameters are used to construct synthetic catalogues of the source events and the subsequent tsunami heights. Processing of these synthetic catalogues produces hazard curves, describing maximum tsunami height as a function of return period, which include ‘error bars’ (confidence intervals) as determined by the Monte Carlo model. Most practical mitigation measures require inundation modelling, and for this purpose we propose using de-aggregation, a process by which a small set of scenarios can be extracted from the NZPTHM for the purpose of detailed inundation modelling.