Uncertainty table for lidar-derived shorelines used when calculating rates in the Digital Shoreline Analysis System software for southeastern Florida (FLse)

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青睐的休闲度假胜地，周边往往坐落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侵蚀威胁，滨海开发仍呈上升态势。为此，社会对精准获取过往与当前岸线变化相关信息的需求日益攀升。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，正依托《全国岸线变化评估》项目，对美国本土毗邻开阔大洋的沙质海岸、阿拉斯加部分区域以及夏威夷群岛的现有可靠历史岸线数据进行汇编整合。 目前尚无被学界广泛认可的岸线变化分析标准。现有岸线数据测量方法与岸线变化速率计算方法因研究而异，导致不同研究结果难以整合至全州或区域尺度的评估工作中。本次全国评估项目的核心动因，便是研发一套覆盖全美各海岸区域的标准化岸线位置变化测量方法，其目标在于以内部统一的规范，推动岸线变化评估结果的周期性、系统化更新工作。