Studying Spatiotemporal Fractional Vegetation Cover Variations from 2000 to 2020 in Changjiang Basin, China with Google Earth Engine

The spatiotemporal fractional vegetation cover (FVC) variations from 2000 to 2020 in the Changjiang basin, China, were studied. With Google Earth Engine (GEE), thousands of Landsat-5, 7, and 8 images were analyzed. In 2000, 2010, and 2020, the FVC increased roughly from the west to the east, crossing the basin. The low FVC areas were mainly around the Qinghai-Tibet Plateau and Changjiang Delta. The basin was well-vegetated from 2000 to 2020, with a minimum yearly average FVC of 67.45%. The FVC increased. At the pixel level, 60.14% of locations had a positive slope of the FVC versus time. Thus, the ecological environments assessed by FVC were healthy for the last 20 years, and the health improved. As shown in this study, GEE is an efficient and effective platform to study natural environments and environmental changes at a large spatial extent and over a long time.