Earth observation data are based on the latest review of the fastest land cover change in the world in the past 20 years (Leper et al., 2005). Analysis shows that the fastest change takes place in Asia, especially in arid areas. High-level tropical deforestation has occurred in the Amazon basin and Southeast Asia, accompanied by the expansion of farmland. There has also been a high level of urban expansion in the tropics. Logging caused by deforestation