Soil moisture quantitative study of the Nanhui tidal flat in the Yangtze River Estuary by using ENVISAT ASAR data

Soil moisture is one of the important ecological parameters of the tidal flat. In this paper, the Nanhui tidal flat in the Yangtze River Estuary as study area, the two close time and HH polarized ENVISAT-ASAR images with different small incidence angles for inversion were received on May 2 and 3, 2005. Then the images based on data pretreatment were normalized for angles, and inversed bare surface roughness and moisture of the Nanhui tidal flat by using Zribi-Dechambre model. The results showed that soil roughness mostly ranged from 0.05cm~0.8cm and soil moisture mainly distributes in the range of 1%~3.8%. At last, the inversed results of soil moisture were validated by field measured data from Shanghai Geological Survey Academy. The RMSE was 3.62%. This research provided an available and suitable method which extracted soil moisture information by using synthetic aperture radar.