OR_transects_LT.shp - Digital Shoreline Analysis System version 4.2 Transects with Long-Term Linear Regression Rate Calculations for Oregon

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的休闲度假胜地，周边往往坐落着拥有高价值不动产的社区。尽管沿海基础设施持续面临洪涝与侵蚀威胁，沿岸开发活动仍呈增长态势。由此，社会对能够精准反映过往与当前海岸线变化情况的信息需求与日俱增。为满足这一国家层面的需求，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》（National Assessment of Shoreline Change）项目，正在汇编美国本土48州、阿拉斯加部分区域及夏威夷州的开放洋面沙质海岸沿线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变化速率计算方案因研究而异，导致相关结果无法整合至州级或区域级评估之中。开展本次《海岸线变化国家评估》项目的核心动因，便是研发一套跨海岸统一的标准化海岸线位置变化测量方法，其目标在于实现以内部一致的方式，定期且系统地更新评估结果的流程。