Abstract: Information on the patterns of land use and land cover change in Central Asia is scarce, and most of the resources used are outdated and unsystematic, which make it difficult to meet the needs of ecology and environmental change research in Central Asia. In this context, compiling the Global Land Cover Characteristics datasets in Central Asia is of great significance in theoretical and practical aspect. In addition, different organizations/institutions develop multiple sets of land use/land cover datasets with various classification systems on global scale depending on their purpose. Those datasets are almost unable to conduct rigorous verification and direct comparison. However, by merging classes based on the classification connotations, these datasets can be used to achieve the purpose of analyzing the macroscopic characteristics of land use and land cover change. In this paper, firstly, the UMD, GLC2000, DISCover, and GlobCover datasets with different land cover classification system are used to extract the long term land cover information in Central Asia. Secondly, all the land cover types are categorized into four classes: arable land, natural vegetation, water bodies and others, to analyze the characteristics and trends in land use and land cover change over the past 30 years in Central Asia.
The results show that there are various types of land cover types in Central Asia which was dominated by grass, bare land, arable land and shrub. Because of the Soviet Union collapse in 1991, arable land decreased sharply from early 1990s to 2000. In comparison with arable land, natural vegetation showed the opposite trend, which indicated a mutual transformation between arable land and natural vegetation area. The area of water bodies fluctuated resulting from the changes in lake area which was influenced by climate fluctuations and human agricultural activities. Urban area experienced an increasing trend, especially during 2000-2009, due to the rapid economic development and the increase of population.
Although the classification system of different Global land cover datasets in Central Asia is not uniform, the pattern of land use and land cover change can well characterized. This shed a light to the LUCC research in Central Asia to some extent. The macroscopic characteristics and trends of land cover in Central Asia can be depicted from the datasets after merging relevant class.Drawn on results of the paper, the land use and land cover pattern has been changed due to the climate changes and human activities in Central Asia. This will bring out a series of environmental issues including soil salinization, serious shortage of water resources, land desertification and other ecological problems, which should be the future direction of land use change research in this area.

Key words: Central Asia, land use/land cover change, remote sensing, Global Land Cover datasets