Estimate ecological indicators of karst rocky desertification by spectral unmixing algorithm

Coverage rates of vegetation and exposed bedrock are two key indicators of karst rocky desertification (KRD) environments. Based on spectral unmixing algorithm, abundance of vegetation and exposed rock were retrieved from the hyperspectral Hyperion image. They were verified by the spectral indices of Karst rocky desertification (SIRD) and vegetation chlorophyll index. It showed that the abundance had significant linear correlation with SIRD. The determinate coefficients (R²) were 0.93, 0.66, 0.84 for vegetation, soil and rock respectively, indicating that the abundances of vegetation and bedrock can characterize their coverage rates to a certain extent. Then, the abundances of vegetation and bedrock were graded and integrated together to evaluate the rocky desertification in typical Karst region. This study implies that spectral unmixing algorithm based on hyperspectral remote sensing image will provide an promising way to monitor and evaluate KRD.