Estimation of wetland aboveground biomass based on SAR image: A case study of Honghe National Natural Reserve in Heilongjiang, China

Wetland is a significant component of the land ecosystems to discover the characteristics and ecological laws. Presently, a common method to estimate a regional wetland biomass is normally based on optical remote sensing images. The estimation of wetland biomass by Synthesize Aperture Radar (SAR) is a novel subject. As a new type sensor, SAR has advantages for wetland applications, therefore, it can be apply for generating some important information about wetland ecology and hydrology, especially with the complex ecological habitat of the transitional place between land and water, radar images can be significant tool for wetland biomass estimation. In this paper, as a case study of SAR application on Honghe National Natural Reserve (HNNR), the wet weight and dry weight field data of 28 quadrats of diverse vegetation in a growing season from the study area in 2009 were gathered, the ASAR image was acquired at the same time with field work. The backscattering coefficient of polarimetric radar and wet weight and dry weight data was taken as correlation variable, the fitting equations of regression models and water cloud model were built to estimate the wet weight and dry weight, a validation was made from 9 measured plots. The research shows the estimation of the wetland biomass by SAR image can be a supplement to optical image with a scientific significance in ecology studying.