Quantification of shoreline movements along the Yukon Territory mainland coast between 1951 and 2011

The Arctic is warming, but the impacts on its coasts are not well documented. To better understand the reaction of Arctic coasts to increasing environmental pressure, shoreline position changes along a 210 km length of the Yukon Territory mainland coast in north-west Canada were investigated for the time period from 1951 to 2011. Shoreline positions were extracted from georeferenced aerial photographs from 1951, 1953, 1954, 1972, 1976, 1992, 1994, and 1996, and from WorldView and GeoEye satellite imagery from 2011. Shoreline change was then analyzed using the Digital Shoreline Analysis System (DSAS) extension for ESRI ArcGIS. Shoreline change rates decelerated to a mean rate of -0.5 m/a between the 1970s to 1990s, which was followed by a significant increase in coastal erosion to -1.3 m/a in the 1990s to 2011 time period. These observation indicate that the current rate of coastal retreat along the Yukon coast is higher than at any time before in the 60 year long observation record.

北极正在变暖，但其海岸所受影响尚未得到充分记录。为更深入理解北极海岸对日益加剧的环境压力的响应，本研究针对加拿大西北部育空地区210千米长的大陆岸段，调查了1951年至2011年间的海岸线位置变化。研究从1951、1953、1954、1972、1976、1992、1994及1996年的地理参考航空照片，以及2011年的WorldView与GeoEye卫星影像中提取海岸线位置。随后借助ESRI ArcGIS的数字海岸线分析系统（Digital Shoreline Analysis System，DSAS）扩展模块对海岸线变化进行分析。结果显示，1970年代至1990年代，海岸线变化速率放缓至年均-0.5米；1990年代至2011年期间，海岸侵蚀显著加剧，速率达到年均-1.3米。上述观测结果表明，育空海岸当前的海岸后退速率，在此次60年的长期观测记录中处于历史最高水平。