基于RS与G IS的典型地区土地利用/覆盖变化研究——以三江源生态环境重点保护区玛多县为例

Study on the LUCC in Typical Regions Based on RS and GIS Methods——Application of Maduo County in the Source Regions ofYangtse, Lancang and Yellow River

典型地区和脆弱区的土地利用/覆盖变化是区域性研究的重要内容。三江源地区是国家级自然保护区,生态系统异常敏感和脆弱。以典型地区玛多县为案例,基于RS和G IS技术,系统研究了该地区土地利用/覆盖变化及其对景观格局的影响,探讨了生态环境演化过程,可为更广泛的区域性综合提供基础。研究发现:①10 a间,该地区湿地、水体和天然草地明显减少,湿地减少比例达到36.63%,大于6 hm2的湖泊减少近半数;沙地,裸地和盐碱地等明显增加,草地退化、沙漠化严重;②天然草地、裸地、沙地、水体、湿地和盐碱地之间的类型转化较为明显,且与水资源又有密切的关系。③多样性、均匀性指数和景观异质程度提高,土地趋于多样化和均匀化;裸地、沙地优势度增加,湿地、水体和天然草地优势度减少;整体破碎化程度呈缓慢减少趋势,而湿地、沙地破碎度增加。④综合土地利用动态度为0.98,天然草地、裸地、湿地、沙地动态面积变化较大。⑤研究区的土地利用/覆盖变化将深刻影响该地区的生态过程,同时还将影响三江源地区的水源涵养和供给。

The study of LUCC in typical and frangible region is the important content of the territorial research. The Source regions of Yangtse, Lancang and Yellow River is the state natural protective regions. The eco-environment is very frangible and sensitive in this area. Give an example of application of Maduo county, this article have systematically studied the LUCC and the influence on Landscape Pattern and discussed the course of LUCC in the region based on RS and GIS Methods. The result will establish the foundation of the territorial research and provide the decision-making basis for the environment protection in the region. Key points include that①During the 10 years, the areas of grasslands, marshes and water is sharply decreasing, the proportion of marshes have decreased 36.63%. The number of lake which the area is more than 6 hectare have half decreased. The sands, the bare-land and the pickled-land is sharply expanding. The degenerate and desertification of grassland is serious. ②The transform of style among the grassland, the sands, the bare-land, the water, the marshes and the pickled-land is obvious. ③The index of diversity and evenness and the extent of Landscape＇s heterogeneity have been improved. The lands are diversifying and evening; The dominance of the sand land and the bare-land have been increased.The dominance of the water, the marshes and the grass-land have been decreased； The overall fragmentation of lands is tend to decrease ,while the fragmentation of the sand land and the marshes is tend to increase. ④The integrate-dynamic extent of land use is 0.98. The area of the grass-land,the bare-land,the marshes and the sand land is sharply changing. ⑤The LUCC of the regions will profoundly impact the eco-environmental evolution process and the self-restraint and supply of water resource in the Source regions of Yangtse, Lancang and Yellow River.