Mapping of biophysical and biochemical properties of coastal tidal wetland habitats with Landsat 8

Abstract

Coastal tidal wetlands are significant and vulnerable aquatic ecosystems.Quantitative remote sensing of biophysical and biochemical properties in coastal tidal wetland habitats through the inversion of physical models has vital practical significance for monitoring ecosystem function, environmental restoration, the global carbon, and nitrogen cycles. The objectives of this research were to map leaf area index (LAI), chlorophyll content, as well as the sensible heat flux, latent heat flux, and productivity in Chongming Dongtan coastal tidal wetland habitats of China and to provide a mapping protocol of biophysical and biochemical properties in Chongming Dongtan wetland for environmental protection and restoration as well as assessment and monitoring. In order to obtain significant information for biodiversity protection and management, a method based on the Soil Canopy Observation of Photosynthesis and Energy fluxes model and lookup table approach has been developed. The results derived from our study contain the reflectance values of Scirpus mariqueter and Phragmites australis spectra are lower than those commonly found for vegetated areas. This may be caused by the dark soil background and low LAI. Moreover, as for the values of latent heat flux (between 120 and 190 W m −2 ) and productivity (between 3 and 14 μmol m −2 s −1 ), mudflats are lower than vegetation. However, the values of sensible heat flux (between 140 and 170 W m −2 ) of mudflats are higher than that of vegetation.

Estimation of aboveground biomass and carbon in palustrine wetland using bands and multispectral indices derived from optical satellite imageries PlanetScope and Sentinel-2A

“…19 Due to difficulties in accessing wetlands, many studies seek to develop innovative and effective methodologies, based on integration of geographical information system and remote sensing (RS) techniques to map, classify, monitor, 20 and analyzing substantial biophysical parameters in the context of regional and global scales. 21,22 Compared with traditional methods, RS technology allows for a quick, accurate, and less destructive estimation of the vegetation biomass and carbon of wetlands, as in situ data are still needed to calibrate models. Wetland biomass studies have mainly focused on AGB and carbon sinks, using optical remote sensing, synthetic aperture radar (SAR) or a combination thereof, and light detection and ranging (LiDAR).…”

“…Among the main sensors used in studies of wetland vegetation and estimation of AGB in blue carbon ecosystems, highlight the Landsat thematic mapper (TM), enhanced thematic mapper (ETM), and operational land imager (OLI) sensors 17,28 as the best option for large scale AGB and Corg sinks modeling. 7,22 Many researchers still prefer medium-resolution satellite images for measuring AGB over long periods and at large areas. 27 Thus, high resolution satellite data is still under-utilized.…”