Uncertainty table for lidar-derived shorelines used when calculating rates in the Digital Shoreline Analysis System software for southern North Carolina (NCsouth)

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目的地，周边往往环绕着坐拥高价值不动产的聚居社区。尽管沿海基础设施面临洪涝与海岸侵蚀的双重威胁，沿岸开发热潮仍有增无减。因此，社会对精准获取过去与当前海岸线变化相关信息的需求与日俱增。为满足这一国家层面的迫切需求，美国地质调查局（U.S. Geological Survey, USGS）旗下的海岸与海洋地质项目组，正依托《海岸线变化国家评估》项目，整编美国本土、阿拉斯加部分区域及夏威夷的开阔洋域沙质海岸沿线已有的可靠历史海岸线数据集。当前学界尚未形成被广泛认可的海岸线变化分析标准。现有海岸线数据的测量手段与变化速率计算方法因研究项目而异，导致各研究结果无法整合为州级或区域级的综合评估。本《海岸线变化国家评估》项目的核心初衷，便是研发一套跨海岸统一、标准化的海岸线位置变化测量方法，以期以内部统一的范式，实现海岸线变化评估结果的定期、系统化更新，简化该更新流程。