Identifying sites of high geoarchaeological potential using aerial LIDAR and GIS on Quadra Island, Canada

Abstract

The dynamic environmental history and relative sea level (RSL) changes experienced on the Northwest Coast of North America during the early post-glacial period and the early Holocene resulted in significant archaeological visibility challenges for prospection of early coastal archaeological sites. This study offers an integrated methodological approach in support of locating palaeo-coastal sites by combining: (1) geomorphic interpretation of landscape attributes captured by LIDAR (Light Detection and Ranging) mapping; (2) GIS-based archaeological site potential mapping; and (3) local RSL history. The RSL history for the study site (Quadra Island, British Columbia, Canada) shows notable regression over the past 14,300 years from a highstand of at least 197 m resulting from post-glacial isostatic rebound. Late Pleistocene and early Holocene palaeo-shorelines are found inland from, and elevated above, modern sea level and represent key areas for archaeological prospecting. Bare-earth Digital Terrain Models (DTMs) derived from the LIDAR dataset were interpreted to identify palaeo-shorelines at 10 m and 30 m above mean sea level. A GIS-derived map was created to identify regions of high archaeological potential. Field validation suggests that this integrated methodology provides a promising approach for archaeological prospection that could be applied to other post-glacial coastal settings.

Keywords:

• Palaeo-shoreline
• Paleoenvironment
• Remote Sensing
• GIS
• Archaeological Methods
• Coastal Geomorphology
• Western Canada
• British Columbia
• Peopling of the Americas

Acknowledgements

The authors would like to sincerely thank and acknowledge the traditional groups with territory on Quadra Island, including the We Wai Kai, Wei Wai Kum, K’omoks, Kwiakah, Klahoose, and Xwemalkhwu First Nations. This research is part of the Discovery Islands Landscape Archaeology (DILA) project funded by the Hakai Institute. We would like to express our sincere appreciation to the Hakai Institute, part of the Tula Foundation, for their integral support for this project. Olav Lian is acknowledged for fieldwork assistance and geomorphic interpretation. Thanks also to Morley Eldridge and Alyssa Parker (Millennia Research Limited) for predictive modeling input and to the DILA field crew for your dedicated work. Thanks to Rob Vogt and Brian Menounos (UNBC) for the LIDAR data acquisition and processing, and also Derek Heathfield (Hakai) for LIDAR post-processing and Keith Holmes (Hakai) for GIS assistance. We would also like to recognize SSHRC for the Canada Graduate Scholarship Master’s Program funding to A. Lausanne, the NSERC Discovery grant program and the Canada Foundation for Innovation Leaders Opportunity Fund for equipment, fieldwork, and analytical support to I. Walker and the University of Victoria.

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

Natural Sciences and Engineering Research Council (NSERC) of Canada's Discovery Grant program (award no. 239751-2011); the Canada Foundation for Innovation (CFI) Leader's Opportunity Fund (project #29502); partnership with the Hakai Institute.