REMOTE MEASUREMENTS OF COASTAL CHANGE USING QUICKBIRD, IKONOS AND AERIAL PHOTOGRAPHY, SACHS HARBOUR, NORTHWEST TERRITORIES,CANADA*

摘要

Remote areas such as the Canadian Arctic Archipelago present unique challenges to mapping shorelines and detecting coastal change. Ground and aerial surveys can be logistically difficult and expensive. New satellites such as QuickBird and IKONOS, represent the highest resolution satellite imagery commercially available and are suitable for a number of coastal applications including comparison to historical aerial photography and detection of decadal scale coastal change. QuickBird from 2003, IKONOS from 2002, and aerial photography from 1985 and 1961 were orthorectified and co-registered using photogrammetric techniques and ground survey control. Waterlines were manually interpreted and digitized and, in the case of aerial photography and QuickBird, also processed using a semi-automated algorithm. In a GIS, shorelines were analysed and quantitative measurements of coastal change were obtained. These reveal a trend since 1961 towards cliff retreat and downdrift migration of foreland beaches. Rates of change have slowed since 1985.