Yifei Wei, Linqing Zhong, Yi Liu, Yuxiang Lu, Xindong He, Maoqing Yao, Guanghui Ren. Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers). 2026.

The eco-environment situation and variation of water source region of Beijing, the capital of China, has been concerned by both central and local government. Located in northwest Beijing, Miyun county is a focus area due to it includes the Miyun reservoir which is the water source for most of Beijing citizens. Taking land cover as an important eco-environment factor, the eco- environment situation and dynamic changing of Miyun Count were studied based on RS, GIS, and GPS. By land cover classification, spatial overlay and statistical analysis, the dynamic changing trend from 1991 to 2001 was revealed. The conclusion is that the eco-environment situation is well, but the dynamic changing trend needs to be concerned because of the fast increase of population.

Beijing, as China's capital, is facing a new opportunity to be built into a competitive world city. Its urban development has entered into a new stage along with China's accession to the WTO and its successful bid for the Olympics in 2008. Quite a few capitals in the world have capitalized on such major international events to improve their comprehensive competitive power. Comparative study is one of the powerful urban research methods to analyze urban spatial development and its capacity. In this stage, the urban built-up area is growing speedily with many kinds of developmental conflicts and issues. The task of the paper is to compare city Beijing's spatial development with the world metropolis' such as London, Paris, Moscow, and Tokyo supported by RS & GIS technology. First of all, the spatial structure information of Beijing and other four world metropolises was extracted from LandSat-7/ETM+ images that were taken by the satellite in 2002/2003. The information was classified into five categories based on the urban land-use classification standard. Then, by combined the classification with the other data such as the large-scale map, the paper analyzed the spatial pattern of these metropolises by using GIS tools at the same scope and scale. Furthermore, the spatial pattern of Beijing was compared with the other four metropolises in order to find the characteristics of Beijing's layout. Finally, the paper pointed out that it was necessary to optimize the urban built-up area and eco-system which is including river, green space and farmlands.

Soil erosion is a serious problem all over the world, especially in China. As the capital of China, soil erosion in Beijing has been concerned a lot by both government and scholars. Located in northwest Beijing, Miyun county is an important region because it includes the Miyun reservoir which is the water source for all of Beijing citizens. Based on the theory and model about soil erosion, the technique method and current situation of soil erosion in Miyun county is studied in this paper supported by GIS and RS. The conclusion is that the existing situation of soil erosion in Miyun county is well due to recent years planting, monitoring, and managing by both central and local government.