Effects of seasonal hydrologic patterns in south Florida wetlands on radar backscatter measured from ERS-2 SAR imagery

摘要: Abstract A multi-year study was carried out to evaluate ERS synthetic aperture radar (SAR) imagery for monitoring surface hydrologic conditions in wetlands of southern Florida. Surface (water level, aboveground biomass, soil moisture) were measured 13 sites (representing three major wetland types) over a 25-month period. SAR collected these on 22 different occasions and correlated with the observations. The results show wide variation backscatter individual when they flooded non-flooded. range (minimum vs. maximum) between 2.3 8.9 dB, 5.0 9.0 dB not flooded. Variations non-flooded consistent theoretical scattering models most part. Backscatter positively field measurements moisture. MIchigan MIcrowave Canopy Scattering (MIMICS) model predicts that should decrease sharply site becomes inundated, but data this drop is only 1–2 dB. This observed both non-wooded wooded sites. as water depth increases predicted by MIMICS sites, similar well. Finally, sensitivity attenuation variations biomass data. inter- intra-annual image intensity region are result changes moisture degree inundation correlation indicates potential using spaceborne systems, such flooding south Florida wetlands.