RS与GIS支持下近50a海南岛西部土地沙漠化时空演变过程研究

Spatio-temporal Changes of Sandy Desertification in Recent 50 Years in Western Hainan Island Based on RS and GIS

海南岛西部是我国惟一的热带稀树干草原沙漠化地区,选取5期遥感数据,采用室内解译和野外检验修正的方法,获得海南岛西部不同时期土地沙漠化数据库。结果分析表明,海南岛西部土地沙漠化在时间上经历了快速发展—初步逆转—全面逆转—波动反复的变化过程;在空间上由沿岸带向昌化、莺歌海两重心收缩、逆转;同时,其发展/逆转过程以沙漠化土地与林地、耕地相互转化为主,伴随着沙漠化土地内部复杂程度间转化。总之,总体逆转、局部反复波动是近50 a海南岛西部土地沙漠化时空演变的基本趋势。

Western Hainan Island is the only savanna region experiencing desertification in China. In this paper, aerial and satellite data and methods include RS interpretation and GIS analysis are used to obtain the evaluation data of land desertification in western Hainan Island in five phases between the late 1950s and the early 2000s. The results suggest that the area of desertification in western Hainan Island has experienced a fluctuating process of four phases in order, which are rapid development, preliminary reversal, comprehenfluctuating process of four phases in order, which are rapid development, preliminary reversal, comprehensive reversal, and rebounding on the floor; the law of spatial variation is that the progress of desertification takes place mainly in the delta of downstream of Changhua River and the lagoon plains in Yinggehai, and desertification area grows shrinkingly and reversely gradually from coastline ; the progress of development and reversion in desertification principally consists of the transformation between woodland, cultivated and desertified land, coupled with complicated transformation among desertification lands. In conclusion, the spatial and temporal trend of desertification in Hainan Island is globally reverse but partially developing.