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Geographic Area Covered: The report covers the Wellington Region, including Wellington City, Porirua, Lower Hutt, Upper Hutt, and Kapiti. 

Summary of the Report: This report outlines the methodology used to create comprehensive earthquake hazard maps for the Wellington Region. The maps combine five types of earthquake hazards: ground shaking, liquefaction, slope failure, fault displacement, and tsunami inundation. Each hazard was previously studied and mapped using digital data in Arc-Info format. The report explains how these individual hazard layers were integrated using a Geographic Information System (GIS) to produce a single map showing relative hazard levels. 
 
Two earthquake scenarios were used for most hazards: a distant moderate earthquake and a large local earthquake on the Wellington Fault. For tsunami hazard, four fault displacement scenarios were considered. Each hazard was assessed for its potential impact on different types of infrastructure, such as residential buildings, roads, bridges, and utilities. Damage ratios were assigned to each infrastructure type based on expected severity. 
 
To combine the hazards meaningfully, the report introduced a methodology that normalises the effects by assuming a uniform distribution of infrastructure across the region. It then calculates expected damage for each hazard type and applies probability and cumulative effect factors to reflect how often each hazard might occur and its long-term impact. These calculations were implemented using a grid-based GIS system, and the results were displayed using a colour scale to indicate relative hazard levels. 
 
The final maps provide a visual representation of earthquake risk across the region, helping planners and decision-makers understand which areas are more vulnerable. The methodology allows for future updates and customisation, such as focusing on specific hazards or infrastructure types. Overall, the report presents a practical and defensible approach to combining multiple earthquake hazards into a single, user-friendly format suitable for land use planning and risk assessment.