Wetland vegetation biomass estimation using Landsat-7 ETM+ data

At present, monitoring, conservation and wise use of wetlands has become an international trend. Using Landst-7 ETM+ data acquired on Oct. 2000, we conducted a digital and rapid estimation of wetland vegetation biomass in the Poyang wetland natural conservation area, which is one of the seven international importance wetlands in China. Firstly, using the ETM band 4, 3 and 2 false color composite as one of the main references, we planned a reasonable sampling biomass field route. Based on geometric co-registration of both the field GPS positioning data and the ETM data, the linear relationships among the field biomass data and some transformed data derived from the ETM data were analyzed statistically. The results show that the sampling biomass data have the best positive correlation to DVI vegetation index data with a coefficient of 0.8546. Therefore, a linear regression model established between the sampling data and DVI data, was applied to estimate the total biomass of the whole Poyang Lake natural conservation area. The resultant total biomass is 10.98×10⁴t.