OuterCapeCod_intersects_STepr.shp - Digital Shoreline Analysis System version 4.3 shoreline intersection points used to calculate short-term (End Point Rate) shoreline change statistics for the Outer Cape Cod coastal region from Long Point in Provincetown to Monomoy Island

Due to continued coastal population growth and increased threats of erosion, current data on trends and rates of shoreline movement are required to inform shoreline and floodplain management. The Massachusetts Office of Coastal Zone Management launched the Shoreline Change Project in 1989 to identify erosion-prone areas of the coast. In 2001, a 1994 shoreline was added to calculate both long- and short-term shoreline change rates at 40-meter intervals along ocean-facing sections of the Massachusetts coast.

The Coastal and Marine Geology Program of the U.S. Geological Survey (USGS) in cooperation with the Massachusetts Office of Coastal Zone Management, has compiled reliable historical shoreline data along open-facing sections of the Massachusetts coast under the Massachusetts Shoreline Change Mapping and Analysis Project 2013 Update. Two oceanfront shorelines for Massachusetts (approximately 1,800 km in total length) were (1) delineated using 2008/09 color aerial orthoimagery, and (2) extracted from topographic LIDAR datasets (2007) obtained from NOAA's Ocean Service, Coastal Services Center. The new shorelines were integrated with existing Massachusetts Office of Coastal Zone Management and USGS historical shoreline data in order to compute long- and short-term rates using the latest version of the Digital Shoreline Analysis System (DSAS).

鉴于沿海人口持续增长与海岸侵蚀威胁加剧的双重背景，当前亟需获取海岸线移动趋势及速率的相关数据，以支撑海岸线与洪泛区管理工作。马萨诸塞州海岸带管理办公室（Massachusetts Office of Coastal Zone Management）于1989年启动海岸线变化项目（Shoreline Change Project），旨在识别沿海易侵蚀区域。2001年，研究团队补充纳入1994年的海岸线数据，用于计算马萨诸塞州面向海洋的岸段中每40米间隔的海岸线长期与短期变化速率。

美国地质调查局（U.S. Geological Survey, USGS）海岸与海洋地质计划联合马萨诸塞州海岸带管理办公室，在《马萨诸塞州海岸线变化制图与分析项目2013年更新》框架下，汇编了马萨诸塞州开阔岸段的可靠历史海岸线数据。该数据集包含两条总长度约1800千米的马萨诸塞州滨海海岸线：其一通过2008/2009年彩色航空正射影像解译勾绘得到，其二则从美国国家海洋和大气管理局（National Oceanic and Atmospheric Administration, NOAA）海洋服务局海岸服务中心提供的2007年地形激光雷达（LIDAR）数据集提取而来。研究团队将新生成的海岸线数据与现有马萨诸塞州海岸带管理办公室及美国地质调查局的历史海岸线数据进行整合，依托最新版数字海岸线分析系统（Digital Shoreline Analysis System, DSAS）计算海岸线的长期与短期变化速率。