Developing new spectral indices for karst rocky desertification monitoring in Southwest China

Karst rocky desertification is a special kind of land desertification developed under violent human impacts on the vulnerable eco-geo-environment of karst ecosystem. The fractional cover of photosynthetic vegetation (PV), non-photosynthetic vegetation (NPV), bare soil and exposed bedrock are key indicators of the extent and degree of land degradation in karst region. The vegetation fractional cover can be estimated approximately from remote sensing with vegetation indices. However, the vegetation indices cannot be easily applicable to all land cover types. In this study, we developed new spectral indices, karst rocky desertification synthesis indices (KRDSI), were then designed based on tied-spectrum permutation and unique spectral characteristics of main land cover types. Comparing with the use of traditional vegetation indices and LSU, the KRDSI was more consistent with the field measurement of main land cover fractions. Our study indicates that KRDSI is a useful tool for karst rocky desertification monitoring with remotely sensed data.