OR_baseline.shp - Offshore baseline for the Oregon coastal region generated to calculate shoreline change rates

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.

滨海沙质海滩是热门的休闲度假胜地，周边往往坐落着坐拥高价值不动产的居民区。尽管沿海基础设施面临洪涝与侵蚀威胁，沿岸开发热度仍持续攀升。因此，社会对能够精准反映海岸过去与当前变迁的信息需求日益增长。为满足这类国家层面的需求，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，正依托全国海岸线变迁评估项目，对美国本土48州以及阿拉斯加州、夏威夷州部分区域的滨海开阔沙岸沿线现有可靠历史海岸线数据进行汇编整合。目前学界尚未形成广泛认可的海岸线变迁分析标准。现有海岸线数据测量方法与变迁速率计算方案因研究而异，无法将各研究结果整合至州级或区域级评估当中。开展全国海岸线变迁评估项目的核心动因，正是研发一套跨海岸统一、可通用的海岸线位置变化标准化测量方法。该项目的目标在于，以内部逻辑自洽的方式，助力海岸线变迁评估结果的定期系统性更新工作。