NASA-USGS National Blue Carbon Monitoring System

USGS-NASA National Blue Carbon Monitoring System

Short Description

This project will evaluate the relative uncertainty of iterative modeling approaches to estimate coastal wetland (marsh and mangrove) C stocks and fluxes based on changes in wetland distributions, using nationally available datasets (Landsat) and as well as finer scale satellite and field derived data in six sentinel sites.


NASA Carbon Monitoring System
Project NNH14AY67I
Title: Linking satellite and soil data to validate coastal wetland "blue carbon" inventories to inform the U.S. national greenhouse gas inventory and to develop monitoring, reporting and verifcation (MRV) and reduced emissions from deforestation and degradation (REDD+) protocols
USGS LandCarbon Program

Project Description

The NASA Carbon Monitoring System (CMS) is poised to fill a missing gap in "blue carbon" accounting by providing a national-scale data framework to integrate and extrapolate field measurements that support national GHG inventory requirements, and testing data needs for quantification of stock-based changes in coastal wetland sediments (soil) and vegetation for eventual REDD+ eligibility. We propose to develop a verifiable carbon (C) monitoring protocol appropriate for national policy and market-based interventions.

Our approach is to refine Landsat-based land cover change data from NOAA’s Coastal Change Analysis Program, with C-relevant attributes from finer scale NASA-derived spectral and RADAR data, as well as broadly available field-data from partner agencies. Synthesizing previously-collected data for 6 sentinel sites along representative coasts of the U.S., we will refine and validate an IPCC-relevant, temporally-explicit (1992-2011) accounting method for coastal wetland C stocks and annual fluxes.Our approach leverages a recent surge in research on the key processes that regulate soil C accumulation in tidal wetlands, which we propose can be captured at large spatial scales using remotely sensed data and GIS modeling.

Net annual C flux into tidal wetland soils is largely a function of vertical accretion due to organic accumulation with sea level rise, or C losses due to oxidation and erosion. Dated soil cores (137Cs, 210Pb) provide quantification of C stocks and long-term rates of net C accretion or loss. The IPCC default value for soil C sequestration in tidal wetlands is 140 g/m2/yr, but rates in US tidal wetlands range from 20-800 g C /m2/yr.

The greatest uncertainty in current "blue carbon " inventory-approaches arises from categorical upscaling, or distributing point data through the estuarine landscape. Both the updated USFWS National Wetland Inventory (NWI) and NOAA’s Landsat-based C-CAP program provide current and historic national distributions of estuarine intertidal wetlands. As linked with USDA SSURGO dataset, the raster-based Landsat-derived C-CAP land cover maps will be used as the primary spatial dataset for tidal wetland distribution and initial estimates of U.S. coastal wetland GHG annual inventories.

Field data provide both a) attributes in a land cover model (tide gauges, elevation) and b) validation datasets (soil cores, biomass, salinity, methane fluxes). While analyses are focused on 6 sites, these field-based data are broadly available across the U.S. through partner agencies such as NOAA, Smithsonian, NSF, EPA, USFWS, and Louisiana’s CRMS databases.

One goal will be to determine the "price of precision" or extent to which finer habitat classifications (hydrology, salinity, sea-level rise) continue to inform C accounting with greater accuracy. Remotely-sensed data products will be derived from ongoing NASA Earth Observations, specifically Landsat, SWOT, Aquarius, PRISM, ALOS-2, UAVSAR, and HICO. Where available, airborne datasets (AVIRIS, AirSWOT) may illustrate the value of future satellite missions (HyspIRI, SWOT) for wetland C accounting.

This project will provide a fundamental data platform to aid the U.S. in quantifying emissions and removals in response to the IPCC Wetlands Supplement (2014) as requested to support the national report in 2017. We recognize that MRV in coastal wetlands will require both remote sensing and field-based data to hindcast and continue monitoring C emissions and removals. Critical products will include network building, data compilation, algorithm development, and validated maps across a series of data-driven scales. Our intensive site validation supports testable indices for accurate C flux accounting, and thus meets several CMS goals such as 1) future application at continental scales, 2) model testing of key drivers of coastal C sequestration and 3) intercomparison and collaboration with associated NASA-supported coastal C cycling research and scenario testing.


Project ContractingOctober 2014
Postdoc HiredDecember 2014
Gulf Team Local Planning Meeting / ReviewMarch 2015
Western Team Local Planning Meeting / ReviewApril 2015
Eastern Team Local Planning Meeting / ReviewMay 2015
Field Data CollectionSummer 2015
Remote Data CollectionSummer 2015
Data Evaluation – ALL TEAM MEETINGDecember 2015
Data – Statistics/UncertaintyMarch 2015
Field Data CollectionSummer 2016
Remote Data CollectionSummer 2016
Protocol Evaluation – ALL TEAM MEETINGDecember 2016
Model Verification/Sensitivity ReportMarch 2017
Draft ReportJuly 2017
Final Report and Associated PublicationsOctober 2017