Digital Shoreline Analysis System version 4.3 Transects with Short-Term End Point Rate Calculations 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.沙质海滨沙滩是热门的休闲度假目的地，周边往往坐落着蕴含高价值不动产的居民区。尽管沿海基础设施长期面临洪涝与侵蚀威胁，滨海开发仍呈持续上升态势。在此背景下，社会对精准获取历史与当前海岸线变化信息的需求日益高涨。为满足这类国家层面的应用需求，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，正在收集美国本土、阿拉斯加部分区域及夏威夷的开放洋域沙质海岸沿线现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，导致不同研究的结果难以整合为州级或区域级的综合评估。本国家评估项目的核心动因，便是研发一套适用于全海岸域、统一规范的海岸线位置变化测量方法，其目标是以内部自洽的方式，推动海岸线变化评估结果的定期系统性更新工作。