SAR-based tidal marsh inundation product development supported by radiometric modeling and ground validation
Abstract
Tidal marshes are among the world's most productive and valuable ecosystems not only because of their vast array of ecosystem services that benefit humans directly including storm surge protection, sediment capture and carbon sequestration, but also because of their importance with respect to biodiversity and biogeochemical cycling. Having well-constrained estimates of hydrologic fluxes and tidal inundation in marsh-estuarine systems is of key importance for understanding the role of these systems in global carbon cycles and as buffer zones for natural hazard mitigation. Yet, tidal hydrologic exchanges are poorly constrained by observations because of challenges posed by accurate measurement of tidal marsh inundation extent and volume, and their change as a function of sub-diurnal tidal influences. Remote sensing imagery acquired by spaceborne and airborne sensors offers a unique capability for assessing tidal marsh inundation state.
Here, we developed and evaluated inundation products based on Synthetic Aperture Radar (SAR) for highly vulnerable tidal marsh systems in the Mid-Atlantic and Gulf of Mexico coastal regions of the United States. Sentinel-1 SAR, PALSAR/PALSAR-2, and UAVSAR imagery from the 2019 AM/PM UAVSAR campaign support algorithm and inundation product development. L-band SAR imagery was used to develop single date inundation products applying approaches that include backscatter thresholding and polarimetric decomposition analyses. Our findings demonstrated good agreement between PALSAR/PALSAR-2 backscatter threshold-based inundation products and in situ inundation sensor observations from pressure transducers (90%, n = 60). Results were consistent with radiometric modeling of radar backscatter dynamics. Our results support a methodology for monitoring of coastal marshes using datasets from on-going and future SAR missions, such as the joint NASA-ISRO NISAR satellite mission currently planned for launch in 2022.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMB063.0007L
- Keywords:
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- 0434 Data sets;
- BIOGEOSCIENCES;
- 0452 Instruments and techniques;
- BIOGEOSCIENCES;
- 0480 Remote sensing;
- BIOGEOSCIENCES;
- 1813 Eco-hydrology;
- HYDROLOGY