Coastal erosion and resulting impacts along the ice-rich permafrost coast of the Yukon Territory, Canada

Due to its fine grained and very ice-rich sediments, the coast of the Yukon Coastal Plain forms a very dynamic landscape. Changing climatic conditions add to this by lengthening open water periods and increasing permafrost temperature, which contributes to an increase of coastal erosion. Even though the Yukon Territory has no permanent settlements along its Beaufort coast, this region is of exceptional value as it serves as a calving area for the Porcupine Caribou Herd and it comprises numerous archaeological sites which are rare remains of the rich human history of this region. The importance of this area is underpinned by the fact that about two third of the coast of the Yukon Territory is protected as part of the Ivvavik National Park, which in turn is a candidate for the UNESCO world heritage site status. Additionally, recurring plans to develop oil and gas-related infrastructure would dramatically change the nature of the coastal environment. Yet, no up-to-date information is available on the erosion of this long coastal stretch, which is detrimental to both environmental and industrial planning in the area. Here, we present initial results of an assessment of shoreline dynamics and their influence on the coastal system in the Ivvavik National Park area. We first quantified shoreline changes of the approximately 150 km long coast by means of remote sensing data. We geocoded aerial photographs from the 1950s, the 1970s and the 1990s to a GeoEye scene from 2011 and digitized the respective shorelines. We then analyzed spatial and temporal shoreline dynamics by using the Esri ArcGIS extension DSAS (Digital Shoreline Analysis System). Then, we coupled these results with a large range of ecological and cultural datasets, including ecological units, freshwater habitat extents and archaeological site positions, in order to determine the vulnerability of the coastal environment of the Ivvavik National Park. Our initial results show that coastal erosion is prevailing along most parts of the coast and only very limited coastal stretches experience accumulation. The analyses allow us to draw initial conclusions about which habitats are most affected by arctic coastal changes and which archaeological sites are prone to get lost in the near future