Clean-up and restoration of urban environments after volcanic eruption

Abstract

As urban development increases across the globe, societies are becoming more exposed to the negative effects of volcanic eruptions. Major cities exposed to volcanism, such as Auckland, New Zealand, require adequate disaster waste management processes to restore urban functionality following an eruption. Pre-event planning is critical to undertaking appropriate disaster waste management following a disaster. Modelling approaches are one the key methodological approaches to characterising and quantifying the effects of future disasters, and so are an important aspect of pre-event planning. Research investigating the interactions between the multitude of volcanic hazards and disaster waste management requirements is required to identify modelling approaches that can be used for pre-event planning purposes.

This thesis first uses case study analysis to contextualise disaster waste management after volcanic eruptions, with the intent of developing an evidence base and identifying important considerations for modelling and contingency planning. Scenarios are developed for the Auckland Volcanic Field (AVF) (The DEVORA Scenarios) using an interdisciplinary approach ensuring that key aspects of AVF volcanism are captured and scenarios are usable for a variety of disaster risk reduction activities, including modelling disaster waste clean-up requirements. Finally, a modelling framework is developed to assess disaster waste clean-up in urban environments. The DEVORA Scenarios are used to demonstrate the utility of this approach.

The findings suggest that the spectrum of different hazards and their unique processes pose a considerable difficulty to managing waste after volcanic eruptions. Specific management requirements include the properties of some volcanic waste products (e.g., lava), large volumes of highly mixed waste streams, and long durations of volcanic activity with substantial uncertainty on the timing and end of waste generating events. Modelling outputs indicate that 11-14x106 tonnes of building debris generated from the scenarios, but the median is 2-3x106 tonnes. Substantial quantities of tephra will require removal (1.5 – 12x109 tonnes). In the event of a future AVF eruption waste streams and quantities are likely to put intense stress and exceed existing waste processing and handling facilities in Auckland.