Subpixel mapping of water cover with MODIS in Tibetan Plateau

Moderate Resolution Imaging Spectroradiometer (MODIS) data is suitable for water mapping, easy to get and having high temporal and wide spatial coverage. This study describes a comprehensive method to produce routinely maps of water cover in Tibetan Plateau with MODIS Surface Reflectance products (MOD09A1) at 463.51 m resolution. Multi-index end-member selecting algorithm was applied to identify end-members including water, forest, grasslands, barren and cloud. Based on the character of land cover spatial distribution, a typical-and-near end-member selecting method and a fully constrained linear unmixing method were adopted to unmix the mixed pixels. The accuracy of the water maps and performance of the algorithm were assessed using 6 pairs of synchronic MODIS/ETM+ images. The method is well-suited to mountainous environment.