基于RS和GIS的绿洲土地利用变化动态监测研究——以香日德绿洲为例

RS/GIS-based Study on the Dynamic Monitoring of Land Use Change in Oases—— A Case Study in the Xiangride oasis

绿洲是干旱荒漠地带一种独特的地理景观,也是干旱区人类经济活动最为集中频繁的区域,对该区域土地利用变化实施动态监测有着重大的意义。通过选取位于柴达木盆地东端都兰县境内的香日德绿洲为研究区,分别利用1987年和1999年覆盖该研究区的TM和ETM遥感影像,进行了基于RS和GIS的土地利用变化动态监测,并结合当地的文献记载,分析、总结了土地利用时空变化特征和驱动力。研究发现,在1987-1999年间,面积变化最大的是土地利用类型是荒漠草场和高寒干旱草场,沙地面积仅增加了5.29km2。

Oases are a kind of special geographic landscape in arid land, and are also the regions where the economic activities are the most concentrated and frequent, so it is of vital significance to dynamically monitor the land use change in these regions. The environmental problems in the Qaidam Basin, such as the land desertification, soil salinization or alkalization, degeneration of grasslands and soil erosion, become more serious along with the large scale exploitation of natural resources, and the structure and spatial distribution of land use are significantly changed. In this paper, a case study on land use change in the Xiangride Oasis, located in Dulan County in the eastern part of the Qaidam Basin, is carried out. By using the TM images of 1987 and the ETM images of 1999, covering the study area, the RS/GIS based dynamic monitoring is carried out, and the temporal spatial change characteristics and the driving forces of land use change are also analyzed and summarized in view of the local documents. The results are that, firstly, RS and GIS can be used to research and dynamically monitor land use change in oases in the arid regions; secondly, the desert steppes were still the dominant land use type during the period of 1987～1999; thirdly, the land use types with the most significant change in area were the desert steppes and the arid alpine steppes; finally, the area of sandlands increased for 5.29 km 2 only.