Digital Shoreline Analysis System (DSAS) version 4.3 transects with end-point rate calculations for sheltered shorelines between the Colville River Delta and Point Barrow for the time period 1947 to 2005

The Arctic Coastal Plain of northern Alaska is an area of strategic economic importance to the United States, is home to remote Native American communities, and encompasses unique habitats of global significance. Coastal erosion along the north coast of Alaska is chronic, widespread, may be accelerating, and is threatening defense and energy-related infrastructure, natural shoreline habitats, and Native communities. There is an increased demand for accurate information regarding past and present shoreline changes across the United States. To meet these national needs, the Coastal and Marine Geology Program of the U.S. Geological Survey (USGS) is compiling existing reliable historical shoreline data along sandy shores of the conterminous United States and parts of Alaska and Hawaii under the National Assessment of Shoreline Change project.
There is no widely accepted standard for analyzing shoreline change. Existing shoreline data measurements and rate calculation methods vary from study to study and prevent combining results into state-wide or regional assessments. The impetus behind the National Assessment project was to develop a standardized method of measuring changes in shoreline position that is consistent from coast to coast. The goal was to facilitate the process of periodically and systematically updating the results in an internally consistent manner.

阿拉斯加北部的北极滨海平原（Arctic Coastal Plain）对美国具有战略经济重要性，既是偏远原住民社群的聚居地，也拥有具有全球意义的独特生境。阿拉斯加北海岸的海岸侵蚀问题长期存在、分布广泛，且可能呈加剧态势，正威胁着国防与能源相关基础设施、自然滨海栖息地以及原住民社区。当前，美国国内对获取准确的历史与当前海岸线变化信息的需求日益增长。为满足这些国家层面的需求，美国地质调查局（U.S. Geological Survey, USGS）海岸与海洋地质项目（Coastal and Marine Geology Program）正依托“国家海岸线变化评估”（National Assessment of Shoreline Change）项目，整合美国本土以及阿拉斯加部分区域、夏威夷的沙质海岸沿线的现有可靠历史海岸线数据。目前尚无被广泛认可的海岸线变化分析标准，现有海岸线数据测量方法与岸线变化速率计算方法因研究各不相同，导致无法将各研究结果整合至州级或区域级评估中。启动“国家海岸线变化评估”项目的动因，是开发一套跨海岸统一的海岸线位置变化标准化测量方法，其目标是以内部一致的方式，定期、系统地更新相关评估成果。