Estimating Soil Moisture Conditions of the Greater Changbai Mountains by Land Surface Temperature and NDVI

Soil moisture is an important indicator of the land surface environment. The combination of land surface temperature (LST) and normalized difference vegetation index (NDVI) could enhance the ability of extracting information on soil moisture conditions. In this study, we employed multitemporal Moderate Resolution Imaging Spectroradiometer (MODIS) data products of LST, NDVI, and land cover types to obtain the information about soil moisture for the greater Changbai Mountains. We selected nine time periods in 2007 for inversion of the soil moisture conditions and focused the analysis on four critical time periods. According to the spatial pattern of the LST and NDVI, we established the ??wet-edge?? and ??dry-edge?? equations and determined the relative parameters. We obtained the temperature-vegetation dryness index (TVDI) using the wet-edge and dry-edge relationships to reveal temporal changes of the land surface soil moisture conditions of the study area. We also analyzed the relationship between different land cover types in five TVDI classes. This paper demonstrates that TVDI is an effective indicator to detect soil moisture status in the greater Changbai Mountains region.