Surface Elevation Table Measurements Along the Atlantic Seaboard, 2024 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 mangronve 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 scoastal 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 sediment erosion tables (SETs) and artificial marker horizons. These two techniques measure the amount of erosion 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 (sediment deposition or erosion).

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.