OR_shorelines.shp - Shorelines of the Oregon coastal region used in shoreline change analysis

Sandy ocean beaches are a popular recreational destination, often surrounded by communities containing valuable real estate. Development is on the rise despite the fact that coastal infrastructure is subjected to flooding and erosion. As a result, there is an increased demand for accurate information regarding past and present shoreline changes. 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 open-ocean 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.

沙质滨海海滩是热门休闲度假目的地，周边往往分布着坐拥高价值不动产的社区。尽管沿海基础设施面临洪涝与海岸侵蚀的双重威胁，沿岸开发仍呈持续上升态势。正因如此，精准掌握海岸线历史与当前变化情况的社会需求日益高涨。为满足此类国家层面的需求，美国地质调查局（U.S. Geological Survey, USGS）下属的海岸与海洋地质项目组，依托“海岸线变化国家评估计划（National Assessment of Shoreline Change project）”，正在整编美国本土48州、阿拉斯加部分区域及夏威夷的开阔洋面沙质海岸沿线现存的可靠历史海岸线数据。
当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案因研究项目而异，导致各研究结果无法整合为州级或区域级的整体评估。本国家评估计划的核心动因，便是制定一套适用于全海岸区域、统一规范的海岸线位置变化测量方法，其目标是推动实现以内部一致的方式定期、系统更新评估结果的流程规范化。