Estuarine Shoreline, Upland Boundary, and Marsh Habitat Change Analyses for the Point Aux Chenes and Grand Bay Estuary Systems, Mississippi and Alabama

Coastal marshes across the Northern Gulf of Mexico are critical ecosystems, providing wildlife habitat, nursery for many species of fish, a carbon sink, and protection of communities from storm surge, but are vulnerable to coastal hazards, such as wave attack, sea level rise, and subsidence. While many marshes accrete vertically to compensate for rising sea level, marsh loss can occur through shoreline exposure to waves and lateral shoreline erosion. However, marsh migration (marsh transgression into upland habitats) may compensate for marsh shoreline erosion. Past marsh upland boundary and shoreline change trends are crucial data for understanding the processes driving erosion and migration and evaluating the overall health and vulnerability of coastal marshes to future scenarios of sea-level rise, climate change, and the global carbon budget.

The data presented in this data release include 1) 1848-2023 shoreline change analysis (vectorized marsh shorelines, shorepoints, and transects with shoreline change rates), 2) 1848-2022 upland boundary change analysis (vectorized upland boundary lines, boundary points, and transects with boundary change rates), 3) raster data for marsh habitat change analysis (1848, 1957/58, and 2019/22 rasters as well as 1848-1957/58, 1848-2019/22, and 1957/58-2019/22 change rasters), and 4) waves, fetch, and associated shoreline change rates for the Point Aux Chenes and Grand Bay estuary systems in Mississippi and Alabama, including the Grand Bay National Estuarine Research Reserve and Grand Bay National Wildlife Refuge.

墨西哥湾北部沿海沼泽是极为关键的滨海生态系统，可为野生生物提供栖息地、为众多鱼类提供育幼栖息地，兼具碳汇功能，并能保护沿岸社区抵御风暴潮侵袭，但此类沼泽却极易受到波浪冲击、海平面上升与地面沉降等海岸灾害的威胁。尽管多数沼泽可通过垂直淤积以抵消海平面上升的影响，但岸线裸露及侧向岸线侵蚀仍会导致沼泽流失。不过，沼泽向高地生境的侵移（marsh transgression into upland habitats，即沼泽迁移）或可弥补岸线侵蚀造成的沼泽损失。过往的沼泽高地边界与岸线变化趋势数据，是厘清侵蚀与迁移驱动过程、评估沿海沼泽在未来海平面上升、气候变化及全球碳收支情景下的整体健康状况与脆弱性的关键基础资料。

本数据集发布所包含的数据如下：1）1848年至2023年岸线变化分析数据（矢量化（vectorized）沼泽岸线、岸点及带有岸线变化速率的断面（transect）数据）；2）1848年至2022年高地边界变化分析数据（矢量化（vectorized）高地边界线、边界点及带有边界变化速率的断面（transect）数据）；3）用于沼泽生境变化分析的栅格（raster）数据（包含1848年、1957/1958年及2019/2022年的栅格数据，以及1848-1957/1958年、1848-2019/2022年及1957/1958-2019/2022年的变化栅格数据）；4）密西西比州与阿拉巴马州的普瓦尚角（Point Aux Chenes）和格兰德湾（Grand Bay）河口系统（包含格兰德湾国家河口研究保护区（Grand Bay National Estuarine Research Reserve）与格兰德湾国家野生动物保护区（Grand Bay National Wildlife Refuge））的波浪、风区（fetch）及相关岸线变化速率数据。