Coastal Resilient Sites, Northeast U.S.

The data depict the relative resilience or vulnerability of every coastal site to six possible scenarios of sea level rise (1 to 6 feet). The Nature Conservancy evaluated the coastal region of nine Northeast and Mid-Atlantic states and estimated the resilience of over 10,000 coastal sites. The goal is to identify the sites most likely to support biological diversity and ecological functions under many levels of sea level rise. To assess site resilience, TNC divided the coast into 10,736 individual sites centered around each tidal marsh or complex of tidal habitats. For each site, estimated the amount of migration space available under six sea-level rise scenarios and identified the amount of buffer area surrounding the whole tidal complex. Then examined the physical properties and condition characteristics of the site and its features using newly developed analyses as well as previously published and peer- reviewed datasets. For tidal complexes, the physical factors assessed included the size and tidal diversity of the migration space, the size and shoreline intricacy of the existing tidal complex, and the amount of shared edge between the tidal complex and its migration space. Condition factors included the amount of hardened shoreline present in the tidal complex, as well as the magnitude of nitrogen inputs, and the quantity of sediment and freshwater inputs estimated for its migration space. Attributes assessed for the buffer area included its size and variety of compatible landforms and soils, the connectedness of its wetlands and percent natural cover. A score was calculated for each site based 80% on the complex and 20% on the buffer, with equal weight given to physical and condition characteristics. Scores were calculated for each of six sea-level rise scenarios (1 to 6 ft.). The final maps are based on the 6-foot scenario because this scenario reveals the sites that have the greatest long-term potential for adaptive response. The 6-foot results were made even more robust by evaluating whether the size of the migration space showed a significant increasing or decreasing trend over the last three scenarios and boosting or penalizing the score slightly based on the results.本数据集刻画了每一处沿海点位针对6种海平面上升情景（1至6英尺）的相对恢复力与脆弱性。自然保护协会（The Nature Conservancy，下称TNC）对美国东北部及大西洋中部沿岸9个州的沿海区域开展了评估，估算了超1万个沿海点位的恢复力水平。本次评估的目标是识别出在多种海平面上升情景下，最能够维持生物多样性与生态系统功能的沿海点位。为评估点位恢复力，TNC将沿岸海域划分为10736个独立点位，每个点位均以一处潮间带沼泽或潮间生境复合体为核心。针对每个点位，研究团队估算了6种海平面上升情景下可利用的迁移空间规模，并确定了整个潮间生境复合体周边的缓冲区域范围。随后该团队借助全新开发的分析方法，以及已发表且经同行评议的数据集，对该点位及其相关特征的物理属性与状态特征展开了调研。针对潮间生境复合体，本次评估的物理因素包括：迁移空间的规模与潮间带多样性、现有潮间生境复合体的规模与岸线复杂度，以及潮间生境复合体与其迁移空间之间的共享边界长度。状态因素则包括：潮间生境复合体中硬化岸线的占比、氮输入强度，以及该点位迁移空间的沉积物与淡水输入量估算值。针对缓冲区域的评估指标包括：其规模、兼容地貌与土壤的多样性、湿地连通性，以及自然植被覆盖占比。每个点位的综合得分以80%权重基于潮间生境复合体的评估结果，20%权重基于缓冲区域的评估结果，且物理属性与状态特征的权重占比相等。研究人员针对6种海平面上升情景（1至6英尺）分别计算了各点位的得分。最终的专题地图基于6英尺海平面上升情景生成，因为该情景能够体现出具备最强长期自适应响应潜力的沿海点位。为进一步强化6英尺情景下的评估结果可靠性，研究团队针对迁移空间规模在最后三种海平面上升情景中的显著增减趋势进行了校验，并根据校验结果对点位得分进行小幅加分或扣分处理。