Monitoring land use and land cover change in the source region of the Yangtze River using multi-temporal Landsat data

The Source Region of the Yangtze River locates in the Qinghai-Tibet Plateau with an area of 142299 km², which is especially sensitive to global warming because of its high elevation and cold environment. To assess the land use and land cover changes from 1975 to 2005, we employed remote sensing and GIS technology to monitor the area of land use and land cover at four times (1975, 1990, 2000, and 2005). The data sources included Landsat multi-spectral scanner (MSS) images acquired in 1975 with an 80-m spatial resolution, Enhanced Thematic Mapper (ETM+) images acquired in 2000 with a 30-m resolution, and Thematic Mapper (TM) images acquired in 1990 and 2005 with a 30-m spatial resolution. The monitoring result shows that, the study area experienced an overall environmental degradation between 1975 and 2005. The environmental degradation includes deforestation, grassland degradation and sandy land expansion.