Modeling of the potential vegetation index of steppe in the western part of the Chinese Loess Plateau

The Chinese Loess Plateau has experienced drastic human-induced land cover change in the last century. The Chinese government has planned a long-term project to restore the ecology and thus the environment. This effort requires the information of the ecological potential. This study presented a complete procedure for spatially modeling the potential vegetation index in arid Loess Plateau region. Spatially distributed wetness index was used to depict the environmental condition at each pixel. Enhanced Vegetation Index (EVI) of current steppe was obtained from Moderate Resolution Imaging Spectroradiometer (MODIS) data. A statistical relationship between the wetness index and the MODIS EVI were established. Based on the statistical relationship, potential EVI was estimated at each pixel. The results show that: (1) the potential EVI ranges from 0.15 to 0.25, (2) actual EVI of irriguous farmlands is obviously greater than the potential EVI of them, and (3) actual EVI of urban area is lower than the potential EVI of them. We believe that the modeled result can effectively facilitate the vegetation restoration planning for this area. In addition, the result may function as a base against which to estimate the historic changes in land cover and land use.