Task 1: Identification of at-risk archaeological sites
Our approach to the classification of at-risk archaeological sites uses a desk-based landscape model that analyses available digital datasets in a Geographical Information System (GIS). Our initial investigation focuses on four coastal areas which were selected on the basis of archaeological importance, magnitude of projected sea-level rise (SLR), availability of data sets and comparison with the earlier Westley et al. (2011) study. There are three activities associated with this task.
(1) Model future SLR: The CARRA project will apply the relative SLR projections of Tom James at Natural Resources Canada, being the most appropriate SLR models to the study areas.
(2) Map Coastal Change: The purpose of this stage is to estimate general patterns of future inundation and coastal erosion and thereby classify the coastline on the basis of its vulnerability. There are three criteria within this classification: inundation, slope and surficial geology. Analysis of the first two criteria will use a Digital Elevation Model (DEM) created from LiDAR data. Firstly, the slope angle of the coastal zones will be calculated from the DEM, as low-sloping areas will be more quickly inundated than steeper sloping landscapes. Secondly, the DEM will be ‘flooded’ with the projected SLR from stage (1). The final step will determine the presence/absence of unconsolidated surficial geology as unconsolidated sediments have a greater potential for coastal erosion when compared to more resistant bedrock. Rates of erosion will be based on mean annual rates of coastal erosion for scattered sites around the province monitored through the Coastal Vulnerability Assessment program of the Geological Survey of Newfoundland and Labrador.
3) Overlay archaeological sites: In this final stage, the location of known archaeological sites within the study areas (based on the official site databases maintained by the Newfoundland and Labrador Provincial Archaeology Office and Parks Canada) will be visited by members of the CARRA team to survey their precise locations and make observations of coastal context and any signs of existing erosion. These site locations will then be overlain onto the coastal vulnerability maps of our study areas. Individual site vulnerability may be both classified according to the generated vulnerability index for the coastal zone in which it is located, or its proximity to future shoreline position and predicted storm surge impacts. In this study we will be able to compare results of the two approaches.