LA_INTERSECTS - Transect-Shoreline Intersection Points for Louisiana Generated to Calculate Shoreline Change Rates

Rates of long-term and short-term shoreline change were generated in a GIS with the Digital Shoreline Analysis System (DSAS) version 2.0, an ArcView extension developed by the U.S. Geological Survey (USGS) in cooperation with TPMC Environmental Services. The extension is designed to efficiently lead a user through the major steps of shoreline change analysis. This extension to ArcView contains three main components that define a baseline, generate orthogonal transects at a user-defined separation along the coast, and calculate rates of change (linear regression, endpoint rate, average of rates, average of endpoints, jackknife).

本研究借助地理信息系统（Geographic Information System，GIS），结合数字岸线分析系统（Digital Shoreline Analysis System，DSAS）2.0版生成了长期与短期岸线变化速率。该系统是美国地质调查局（U.S. Geological Survey，USGS）与TPMC环境服务公司联合开发的ArcView扩展插件。该扩展插件旨在高效引导用户完成岸线变化分析的核心步骤。这款ArcView扩展插件包含三大核心组件：一是划定岸线基线，二是沿海岸按照用户自定义的间距生成正交断面，三是计算岸线变化速率，具体方法包括线性回归（linear regression）、端点速率（endpoint rate）、速率平均值（average of rates）、端点平均值（average of endpoints）以及刀切法（jackknife）。