University of Southampton OCS (beta), CAA 2012

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A Digital Terrain Analysis and Multi-Critera Evaluation of Higher Archaeological Potential Landforms in Northern Alaska.
Sarah Kessick

Last modified: 2011-12-22

Abstract


A review of the archaeological literature for northern Alaska revealed that archaeologists have used landforms as a way to focus archaeological surveys in the Brooks Range, Arctic Foothills, and Arctic Coastal Plain of Alaska throughout the last 60 years. Due to factors that limit the ability to survey 100 percent of a study area (e.g., varying methodologies, time constraints, budget), archaeologists in Alaska tend to focus archaeological fieldwork and subsurface testing on landforms such as ridges, terraces, and knolls, which are believed to have a higher potential for site occurrence. These landforms are often associated with alluvial environments, such as resource bearing streams. Archaeologists have been successful in finding archaeological sites in alluvial environments because these areas have been used intensively through time by previous occupants for hunting and gathering, and natural site-formation processes in these types of settings often preserve cultural remains.

After a review of archaeological survey methods in northern Alaska, which often target specific landforms in alluvial landscapes, and considering the availability of a high resolution Light Detecting and Ranging (LiDAR) Digital Elevation Model (DEM) for a proposed 100 mile road corridor in northern Alaska, a Geographical Information System (GIS) is used to model, isolate, rank, and map landforms considered to have a higher potential for locating archaeological sites.  A terrain analysis isolates two high archaeological potential landform types in the project area: level areas near terrain breaks (LANTB) and ridges. A network of ranked stream orders, based on their number of tributaries (i.e., the greater number of stream tributaries, the higher the stream order rank assigned to a particular stream) is used to perform a Multi-Criteria Evaluation (MCE) of the isolated LANTBs and ridges. The result is a model that identifies higher archaeological potential landforms, i.e., areas deemed more attractive to ancient occupants due to favorable landform characteristics (LANTBs and ridges) based on their proximity to streams.

LandSerf© is used for the terrain analysis and landform classification. LandSerf is an open source GIS software which performs multi-scale surface parameter and feature (landform) extractions (Wood 2009) from DEMs using quadratic approximation. An integrated GIS software called IDRISI© is used to rank the selected landforms (LANTB and ridges) based on their proximity to higher order streams using MCE techniques. The Multi-Criteria Evaluation procedure called Weighted Linear Combination produced a continuous mapping of suitability of digitally extracted higher archaeological potential landforms.

The results of the terrain analysis and MCE were overlaid on the high resolution hillshade images and orthographic photos in GIS for the proposed road corridor in northern Alaska. Coupled with knowledge gained from cultural resources field surveys conducted in 2010, the visual assessment indicated that the methods applied in this model appear to have successfully represented higher probability landforms in the project area and may be a useful prospect for guiding future archaeological surveys in Alaska.


Keywords


Terrain analysis; MCE; Alaska; archaeological survey