USGS Map service: National Shoreline Change - Historic Shorelines by State

There are critical needs for a nationwide compilation of reliable shoreline data. To meet these needs, the USGS has produced a comprehensive database of digital vector shorelines by compiling shoreline positions from pre-existing historical shoreline databases and by generating historical and modern shoreline data. Historical shoreline positions serve as easily understood features that can be used to describe the movement of beaches through time. These data are used to calculate rates of shoreline change for the U.S. Geological Survey's (USGS) National Assessment of Shoreline Change Project.

Each shoreline may represent a compilation of data from one or more sources for one or more dates provided by one or more agencies. Details regarding source are provided in the 'Data Quality Information' section of the individual shoreline metadata report.

To make this shoreline data more accessible to the public and other agencies, the USGS created this web service. This web service was created utilizing ESRI ArcServer. Vector shoreline layers were collected, organized by state, and symbology made consistent among similar data sets. This service meets open geospatial consortium standards.

全国范围内亟需一套可靠的海岸线数据集汇编。为满足这一需求，美国地质调查局（U.S. Geological Survey, USGS）通过整合既有历史海岸线数据库中的海岸线点位，并生成历史与现代海岸线数据，构建了一套完整的数字矢量海岸线数据库。历史海岸线点位是易于理解的特征要素，可用于描述海滩随时间的迁移变化。此类数据被用于计算美国地质调查局（USGS）国家海岸线变化评估项目中的海岸线变化速率。

每条海岸线数据可能整合了单个或多个机构在单个或多个日期下的多源数据。数据来源的详细信息可查阅各海岸线元数据报告中的"数据质量信息"章节。

为便于公众及其他机构获取该海岸线数据，美国地质调查局开发了本网络服务。该网络服务基于ESRI ArcServer搭建。矢量海岸线图层已按州进行收集与整理，并确保同类数据集的符号系统统一规范。本服务符合开放地理空间联盟（Open Geospatial Consortium, OGC）标准。