Mapping irregularly flooded wetlands, high marsh, and salt pannes/flats along the northern Gulf of Mexico coast (ver. 2.0, June 2023)

This data release includes geospatial data for irregularly flooded wetlands and high marsh and salt pannes/flats along the northern Gulf of Mexico coast from Texas to Florida. Specifically, this release includes seven products: (1) a map highlighting the continuous probability that an area is an irregularly flooded wetland; (2) a map of irregularly flooded wetland probability reclassified into four bins; (3) a map delineating high marsh and salt pannes/flats; (4) a map from Lake Pontchartrain, Louisiana to the Florida Big Bend delineating the coverage of irregularly flooded wetlands that have Juncus roemerianus (Black needlerush) as the dominant vegetation species; (5) a spatial metadata file showing what elevation data were used for specific locations; (6) a supplemental version of the high marsh and salt pannes/flats map that has a second class for high marsh for parts of Texas where succulents and Distichlis spicata were dominant species; and (7) a dataset of supplemental project-specific field reference data collected throughout the northern Gulf of Mexico coast. Collectively, the products in this data release were developed using a two-step approach that utilized the best-available elevation data and satellite data from 2018 to 2020. The first step in the process was to create a probabilistic map of irregularly flooded wetlands using light detection and ranging (lidar)-derived digital elevation models (DEMs), tidal datums, and nuisance flooding levels. Monte Carlo simulations were used to propagate uncertainty in elevation-based data, and existing land cover data were used to restrict the output to coastal wetland areas. Due to the focus of this study on high marsh, these coastal wetland areas did not include tidal forested fresh wetlands. The second step was to delineate high marsh and salt pannes/flats using reference data which included project-specific data collection in collaboration with land managers and other ancillary datasets across the northern Gulf of Mexico coast. These data were combined with Sentinel-1 synthetic aperture radar imagery, multispectral optical satellite imagery from Sentinel-2, DEMs, and the irregularly flooded wetland probability layer to generate a contemporary map of high marsh and salt pannes/flats along the northern Gulf of Mexico coast. This product is the first regional map of these wetland systems across the northern Gulf of Mexico coast.

本数据集发布包含墨西哥湾北部沿岸（从德克萨斯州至佛罗里达州）的不规则淹水湿地、高潮滩与盐沼洼地/滩涂的地理空间数据。
本次发布共包含7项产品：(1) 展示区域为不规则淹水湿地的连续概率分布图；(2) 将不规则淹水湿地概率重分类为4个等级的分布图；(3) 划定高潮滩与盐沼洼地/滩涂的分布图；(4) 覆盖路易斯安那州庞恰特雷恩湖至佛罗里达大弯曲区的、以黑针蔺（Juncus roemerianus）为优势植被的不规则淹水湿地分布范围图；(5) 展示特定位置所用高程数据的空间元数据文件；(6) 高潮滩与盐沼洼地/滩涂地图的补充版本：针对德克萨斯州部分以肉质植物和盐地鼠尾粟（Distichlis spicata）为优势物种的区域，该版本为高潮滩增设了第二分类；(7) 覆盖墨西哥湾北部沿岸的项目专属野外参考数据集（实地采集所得）。
本数据集发布内的所有产品均采用两步法开发，整合了2018至2020年的最优可用高程数据与卫星数据。
第一步：基于激光雷达（lidar）获取的数字高程模型（DEMs）、潮汐基准面与日常淹水水位，生成不规则淹水湿地的概率分布图；通过蒙特卡洛模拟实现高程数据的不确定性传递，并结合现有土地覆盖数据将输出范围限定在滨海湿地区域。鉴于本研究聚焦高潮滩，上述滨海湿地范围未包含潮汐森林淡水湿地。
第二步：依托野外参考数据（包括与土地管理者合作采集的项目专属数据，以及墨西哥湾北部沿岸的其他辅助数据集）划定高潮滩与盐沼洼地/滩涂；将这些数据与哨兵-1号（Sentinel-1）合成孔径雷达影像、哨兵-2号（Sentinel-2）多光谱光学卫星影像、DEMs及不规则淹水湿地概率图层相结合，生成墨西哥湾北部沿岸高潮滩与盐沼洼地/滩涂的现势分布图。
本产品是墨西哥湾北部沿岸此类湿地系统的首份区域级分布图。