Surface Elevation Table Measurements Along the Atlantic Seaboard, 2025 Cumulative Data Package

The National Park Service (NPS) in response to the growing evidence and awareness of the effects of climate change on federal lands determined that monitoring wetland elevation change is a top priority in Atlantic coastal parks. As a result several NPS Inventory and Monitoring Division (IMD) Networks in collaboration with colleagues from the U.S. Geological Survey (USGS) and The National Oceanic and Atmospheric Administration (NOAA) have developed a protocol for monitoring wetland elevation change and other processes important for determining the viability of coastal wetland communities. These data consist of measurements made using the Surface Elevation Table (SET) and Marker Horizon techniques at five NPS Inventory and Monitoring Networks across the Atlantic seaboard: the Northeast Temperate Network (NETN) the Northeast Coastal and Barrier Network (NCBN) the National Capital Region Network (NCRN) the Southeast Coast Network (SECN) and the South Florida/Caribbean Network (SFCN).

The mean elevation of salt marsh surfaces must increase to keep pace with the annual rise in sea level and subsidence of organic substrates in salt marshes and mangrove forests. If the sedimentation rates in a salt marsh or mangrove forest do not equal or exceed the net loss in elevation due to the steady increase in sea level and soil subsidence it will drown . When a coastal wetland drowns the surface of the wetland becomes sub-tidal which can cause drastic habitat changes such as the conversion of vegetated salt marsh or mangrove forest to unvegetated mud flat. Understanding changes in relative elevation is important for interpreting changes in coastal wetland vegetation communities. Coastal wetland erosion and accretion are also important parameters for measuring the response of formerly impounded wetlands to restoration of tidal influence and will be particularly critical if the rate of sea level rise accelerates as predicted. This project is also part of a worldwide effort to monitor sea level rise with surface elevation tables (SETs) and artificial marker horizons. These two techniques measure elevation change and accretion on salt marsh surfaces.

Monitoring Objectives: Determine long term trends in coastal wetland elevation at selected sites in NPS park units and factors contributing to the observed changes.

This data package contains a cumulative record of all monitoring data collected at IMD park units through the most recent field season and is organized into six (6) datasets:

event_data_YYYYMMDD.csv - sample event-level data including date time location type of data collected etc.

pin_data_YYYYMMDD.csv - marsh surface elevation data collected using the SET instrument.

marker_horizon_data_YYYYMMDD.csv - marsh sediment accretion data collected by sampling marker horizon plots using liquid nitrogen or mechanical coring techniques.

pin_group_data_YYYYMMDD.csv - description of all sets of pins used during data collection using the SET instrument including lengths diameters and materials.

station_data_YYYYMMDD.csv - precise location data and descriptive information for all SET stations.

critical_information_data_YYYYMMDD.csv - summary table containing information on any deviations from Standard Operating Procedures that may affect comparison of data across time at a given station (e.g. significant storm events).

Note that the date at the end of each data file represents the date that the dataset was published.

鉴于气候变化对联邦土地的影响证据日益充分、社会认知持续深化，美国国家公园管理局（National Park Service, NPS）将湿地高程变化监测列为大西洋沿岸公园的核心工作任务。为此，美国国家公园管理局下属多个清查与监测处（Inventory and Monitoring Division, IMD）网络联合美国地质调查局（U.S. Geological Survey, USGS）及美国国家海洋和大气管理局（National Oceanic and Atmospheric Administration, NOAA）的合作团队，研发了一套用于监测湿地高程变化及其他影响滨海湿地群落存续的关键过程的监测规范。本数据集涵盖沿大西洋沿岸分布的5个美国国家公园管理局清查与监测处网络站点中，采用地表高程表（Surface Elevation Table, SET）与标记层（Marker Horizon）技术采集的监测数据，涉及的网络分别为：东北温带网络（Northeast Temperate Network, NETN）、东北海岸与屏障网络（Northeast Coastal and Barrier Network, NCBN）、国家首都区网络（National Capital Region Network, NCRN）、东南海岸网络（Southeast Coast Network, SECN）以及南佛罗里达/加勒比海网络（South Florida/Caribbean Network, SFCN）。
盐沼与红树林湿地的地表平均高程需与海平面年上升量及湿地内有机基质的沉降速率同步提升，方可维持自身存续。若盐沼或红树林的沉积速率无法抵消或超过因海平面持续上升与土壤沉降导致的高程净损失，湿地将发生浸没。滨海湿地浸没后，其地表将转为潮下带环境，进而引发剧烈生境变化，例如将有植被覆盖的盐沼或红树林转化为无植被泥滩。厘清相对高程变化，对解析滨海湿地植被群落的演变至关重要。滨海湿地的侵蚀与淤积也是评估曾被围封的湿地恢复潮汐连通性后响应情况的关键参数；若海平面上升速率如预测般加快，该参数的重要性将进一步凸显。本项目同时隶属于全球范围内利用地表高程表（SET）与人工标记层技术监测海平面上升的合作计划，该两项技术可量化盐沼地表的高程变化与淤积量。
监测目标：明确美国国家公园管理局管辖公园内选定滨海湿地站点的高程长期变化趋势，以及引发观测到的高程变化的影响因素。
本数据包汇总了截至最新野外季期间，清查与监测处下属公园站点采集的全部监测数据，并分为以下6个数据集：
event_data_YYYYMMDD.csv：事件级样本数据，包含采集日期、时间、点位、数据类型等信息。
pin_data_YYYYMMDD.csv：采用地表高程表（SET）仪器采集的盐沼地表高程数据。
marker_horizon_data_YYYYMMDD.csv：通过液氮法或机械取芯法对标记层样地进行采样后获得的盐沼沉积物淤积数据。
pin_group_data_YYYYMMDD.csv：采用地表高程表（SET）仪器采集数据时所用的全部测杆组的详细信息，包括长度、直径与材质。
station_data_YYYYMMDD.csv：所有地表高程表（SET）监测站点的精准位置数据与描述性信息。
critical_information_data_YYYYMMDD.csv：汇总表，记录所有可能影响单站点跨时段数据对比的标准作业程序偏离情况（例如重大风暴事件）。
请注意，各数据文件后缀的日期代表该数据集的发布日期。