Mitigating Risk

Geographic Information System model predicts areas of archaeological risk.

This innovative research and design project for the NZ Transport Agency involved the development of a GIS model to identify areas of potential archaeological risk to the State Highway network. A deductive site suitability approach was taken using ArcGIS fuzzy logic techniques. This Expert System was guided by an Archaeologist with extensive knowledge of the State Highway 11 study area on Northland’s east coast. The deductive model hypothesis focused on environmental influencing factors that are thought to have contributed to human settlement decision making prior to European contact.

The predictive rules applied were;
1. Preference for close proximity to volcanic surface rocks, i.e. for gardening, settlement foci around scoria cones
2. Preference for ridges and elevated plateaus for defensive positions
3. Preference for close proximity to water sources (coastlines, rivers and lakes)

A set of user guide tables were developed to help interpret the archaeological risk map, and indicate when Archaeologists should be engaged for particular types of planned road work. The model was tested and confirmed that 93% of archaeological sites were within the very high risk zone. Recommended future enhancements include social and cultural influences on human settlement patterns.

Benefits to the client included cost savings resulting from greater efficiency.  This project aims to minimise time consuming and costly delays to road maintenance and development projects. The archaeological risk map allows Asset Managers to plan future expenditure more effectively and improve cultural heritage impact performance by presenting a more comprehensive spatial representation of risk.