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.

滨海沙质海滩是广受欢迎的休闲度假胜地，周边往往坐落着拥有高价值不动产的社区。尽管沿海基础设施面临洪涝与侵蚀威胁，滨海开发热度仍持续攀升。正因如此，精准获取岸线历史与现状变化相关信息的需求日益高涨。为满足此类全国性需求，美国地质调查局（U.S. Geological Survey, USGS）海岸与海洋地质项目组依托《全国岸线变化评估》（National Assessment of Shoreline Change）项目，正在汇编美国本土（48个毗连州）、阿拉斯加部分区域及夏威夷群岛的开放洋域沙质海岸沿线已有的可靠历史岸线数据。

目前尚无被广泛认可的岸线变化分析标准，现有岸线数据的测量方法与岸线变化速率计算方法因研究而异，无法将不同研究的结果整合为州级或区域级评估数据。本全国评估项目的核心动因，正是研发一套跨海岸统一的标准化岸线位置变化测量方法，其目标是以内部一致的方式，为岸线变化结果的周期性系统更新工作提供便利。