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基于马尔科夫链模型的长江源区土地覆盖格局变化特征

杜际增1,王根绪1**,李元寿2   

  1. (1中国科学院水利部成都山地灾害与环境研究所,  成都 610041; 2中国气象局,  北京 100081)
  • 出版日期:2015-01-10 发布日期:2015-01-10

Changes of land cover pattern in the source region of Yangtze River based on Markov process.

DU Ji-zeng1, WANG Gen-xu1**, LI Yuan-shou2   

  1. (1The Key Laboratory of Mountain Environment Evolution and Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, China; 2China Meteorological Administrations, Beijing 100081, China)
  • Online:2015-01-10 Published:2015-01-10

摘要:

利用长江源区1986、2000与2014年3期的遥感影像, 结合实地野外考察获得该地区在这3个时间点的土地覆盖类型图。根据各时期之间的土地覆盖格局的变化确定土地类型之间的转移概率, 进一步完成对该地区马尔科夫链模型的构建、检验与预测。结果表明:1986—2014年, 长江源区的土地覆盖格局的变化特征符合马尔科夫过程, 通过马尔科夫链模型能够对该地区的覆盖格局变化过程进行有效的模拟;长江源区的土地覆被退化趋势明显, 湿地、中高覆盖草地等面积不断下降, 裸地、沙地以及低覆盖草地等面积则一直在增加;2000年以后, 由于三江源区自然保护区的建立以及降水量的增加等因素影响, 长江源区的植被退化状况得到明显改善。
 

关键词: 油蒿, 树干茎流, 土壤湿润锋, 柠条

Abstract:

Based on the spatial dataset obtained from the TM remote sensing data in 1986, 2000 and 2014, combined with the field investigation data, the maps of the land cover pattern in the source of Yangtze River were made, and the transition probability between all kinds of land cover was determined by using the amplitude of the land cover pattern changes during the three different periods. In addition, Markov model of land cover change in this region was established and validated by the transition probability. The characteristics and tendency of land cover changes were analyzed and forecasted with the Markov model. The results indicated that the characteristics of land cover change were coincided to Markov process, thus, the Markov model could be used to validly simulate the process of land cover change in the source region of Yangtze River. The degradation trend of land cover in the source region of Yangtze River was extremely evident. The areas of wetland and alpine grassland with highmid coverage continued to decline, while the area of low cover alpine grassland and bare land had consistently been increasing. However, with the establishment of the Three Rivers Headwaters Nature Reserve and the increase of precipitation in this region since 2000, the degradation trend of vegetation has been relieved obviously.
 

Key words: Caragana korshinskii, Artemisia ordosica, soil wetting front, stemflow