呼伦贝尔草原沙漠化现状及历史演变研究

呼伦贝尔草原是我国优良的天然牧场，由于其所处的特殊地理位置，生态环境极其脆弱，在自然因素和人为因素的共同作用下，近一个世纪以来区内生态环境退化加剧，表现为土地沙漠化，草场退化和水土流失加剧等过程。在软硬件系统支持下应用GIS和遥感技术．结合前人研究成果和野外调查，通过基于知识的多重判据复合分类实现多源信息的集成，对呼伦贝尔草原沙漠化现状及沙地演变进行了系统研究。结果表明，呼伦贝尔草原沙漠化面积已达20893．57km^2，占总土地面积的25％。沙漠化总体特征表现为局部地段逆转，而总体仍在发展。近一个世纪以来，区内沙漠化的强烈发展是由于毁林、滥垦和过度放牧。

Study on the Actualty and Historical Evolution of Desertification in the Hulunbeir Grasslands

The Hulunbeir Grasslands is an eminent pasture in Inner Mongolia of China, however, its ecological environment is very fragile due to its especial geographical location, and the grasslands is rapidly degenerated due to both natural factors and human activities, which include mainly the land desertification, degeneration of the grasslands, serious soil erosion, etc. in this region. Under the support of both hardware and software and the combination of the predecessors' achievements in scientific research with the field investigation, in this paper, the actuality of land desertification and the evolution of sandlands in the Hulunbeir Grasslands are systematically studied by using GIS and RS technologies to achieve the integration of the multi-source information through the knowledge-based compound classification of the multiple criterions. The results show that the land desertification has been rapidly developed due to the severe deforestation, excessive reclamation and pasturing since the recent century. In the Hulunbeir Grasslands, the area of the desertified lands is currently up to 20 893.57km2 and occupies 25% of the total grasslands area, which is dominated by the slightly-desertified grasslands, and the area of the desertified farmlands is very small; The land desertification is reversed in some areas but is developed in overall due to the difference of the natural conditions and mode and intensity of human activities. In order to control the rapid development of land desertification in the region, the resources of the natural vegetation and of the natural grasslands can be moderately and rationally exploited and utilized in some areas but must be strictly conserved in some other areas.