Soil moisture evaluation in the Three Gorges Reservoir area using ENVISAT ASAR data

This paper presents a method to estimate the soil moisture using ENVISAT ASAR data in the Three Gorges Reservoir area in China. Firstly, this study introduces a semi-empirical model for bare surface scattering and a water-cloud model for the elimination of the impact of the vegetation cover. Secondly, a new combined roughness parameter is introduced to describe the roughness of soil surface. Thirdly, we analyze the relationship between soil roughness and radar backscattering coefficient and that between soil moisture content and backscattering coefficient respectively. Then the soil moisture inversion algorithm is achieved through programming. Finally, an evident logarithmic relationship between radar backscattering coefficient and soil moisture is presented. In conclusion, the experiments prove that the method is fast, efficient and widely applicable.