基于遥感技术的宁夏南部山区LUCC研究

Study on Land Use/Cover Change in Mountain Areas of Southern Ningxia Based on RS Technology

以1975、1987和2001年的LandsatTM/MSS影像为数据源,利用遥感(RS)和地理信息系统(GIS)相结合的技术,运用统计方法和转移矩阵对宁夏南部山区26年来的土地利用/覆被变化(LUCC)状况进行了研究。结果表明,宁夏南部山区土地利用/覆被的主要类型是耕地,其次是草地和林地;耕地在1987年达到了最高峰,为790312.06hm2,占总土地面积的70.03%。转移矩阵分析得出,在1975～1987年间,有370770.52hm2草地和39813.57hm2林地转化成耕地;而在1987～2001年间又有316865.89hm2耕地转化为草地和50729.16hm2耕地转化为林地。导致这种变化的原因是上世纪70、80年代当地经济发展思路以基本农田建设为中心,鼓励农民进行开荒种地;而到90年代后,国家开发政策的转变和重大生态工程的建设,特别是退耕还林还草,为当地草地和林地的恢复起到了重要的作用。

With the integrated technology of Remote Sensing （RS） and Geographic Information System（GIS）, the status of LUCC in the mountain areas of southern Ningxia Hui Autonomous Region is thoroughly studied by statistics and conversion matrix based on the remote sensing imagery date of 1975, 1985 and 2001. The main resuhs are as follows. （1） The main styles of LUCC in the study area is farmland, and the following is grassland and woodland. The area of farmland reaches its maximum in 1987, with 790 312.06 hm^2, taking 70.03% in the total land area. （2） The study results from conversion matrix indicate that there is 370 770.52 hm^2 grassland and 39 813.57 hm^2 woodland that had changed to farmland from 1975 to 1987. But from 1987 to 2001, there are 316 865.89 hm^2 farmland that had changed to grassland and 50 729.16 hm^2 farmland changed to woodland. The main reason that leads to this variation is that the local economy development was based on construction of farmland from 1975 to 1987. In this period, the development policy encouraged farmer to cultivate wasteland. But after 1990, the national exploitation policy changed greatly and carried out some zoology project, especially Returning Farmland to Forests and Grassland Project. Such policies and projects play an important role in the recovery process of grassland and woodland.