Coastwide Reference Monitoring System (CRMS) 2016 Site 0376 land-water classification data

Wetland restoration efforts conducted by the Coastal Wetlands Planning, Protection and Restoration Act (CWPPRA) in Louisiana rely on monitoring efforts to determine the efficacy of these efforts. The Coastwide Reference Monitoring System (CRMS) was developed to assist in a multiple-reference approach that uses aspects of hydrogeomorphic functional assessments and probabilistic sampling for monitoring. The CRMS program includes a suite of approximately 390 sites that encompass the range of hydrological and ecological conditions for each stratum. As part of CRMS, land and water classifications are created from Digital Orthophoto Quarter Quadrangles (DOQQs) approximately every three years at all CRMS sites. A DOQQ is a raster image in which displacement in the image caused by sensor orientation and terrain relief has been removed and combines the image characteristics of a photo with geometric qualities of a map. The DOQQs generated for this project consist of 2016 Color Infrared (CIR) Digital Imagery. These images were classified into land and water categories using a threshold of the near infrared (NIR) band, followed by supervised and unsupervised classification. Initial classification results are then reviewed by multiple image analysts to identify and manually recode errors. The final land-water classifications are intended to serve as both geographic and quantitative assessments of landscape composition on the date of acquisition. Three previous assessments have been conducted (2005, 2008, and 2012). Once the program creates enough data points for statistical analyses, these data will be used for land area change rate calculation.

美国路易斯安那州依托海岸湿地规划、保护与恢复法案（Coastal Wetlands Planning, Protection and Restoration Act, CWPPRA）开展的湿地修复工程，需依托监测工作评估此类工程的实施成效。全海岸参考监测系统（Coastwide Reference Monitoring System, CRMS）应运而生，旨在支撑多参考点监测方案，该方案融合水文地貌功能评估与概率抽样技术开展监测工作。CRMS项目共设置约390个监测站点，覆盖各分层类别的水文与生态条件全范围。作为CRMS的组成部分，所有监测站点每三年左右便会基于数字正射影像四分之一幅图（Digital Orthophoto Quarter Quadrangles, DOQQs）完成水陆分类工作。数字正射影像四分之一幅图属于栅格影像，已校正由传感器姿态与地形起伏导致的影像位移，兼具航空影像的成像特性与地图的几何精度。本次项目生成的DOQQs采用2016年彩色红外（Color Infrared, CIR）数字影像制作。研究团队首先通过近红外（Near Infrared, NIR）波段阈值法对上述影像进行初步分类，随后辅以监督分类与非监督分类算法完成细化分类。初步分类结果将由多名影像分析师逐一复核，识别并手动修正分类误差。最终水陆分类成果可用于开展影像获取当日景观组成的地理空间与定量评估。此前项目已完成三次评估工作（分别为2005年、2008年与2012年）。待项目积累足够可用于统计分析的数据点后，相关数据将被用于计算陆地面积变化速率。