东平湖湿地景观演变对人类活动的响应机制

为探索南水北调工程通水前后湿地景观格局变化,采用决策树分类法,对2000年、2009年和2014年3期Landsat影像进行分类;在分类结果的基础上,应用转移矩阵和景观指数等方法,分析不同时期景观格局的特点及驱动因素;最后应用马尔科夫模型,对研究区景观格局演变进行预测。结果表明:水域周边出现了更多的建筑用地,景观指数INP由7 174增长至10 334,蔓延度指数IC由64.594 4减少至63.651 5,景观格局总体呈破碎趋势,景观破碎度增加,景观异质性增强;2009—2014年香农均匀度指数ISHE和香农多样性指数ISHD指数小幅上升,景观格局集聚度水平提高,但是与2000年的景观格局水平存在较大差距,部分天然湿地被人工湿地取代,导致湿地生态功能退化。

Impacts of human activities on change of wetland landscape in Dongping lake area

In order to explore the change of wetland landscape pattern after the South-to-North Water Diversion Project, three Landsat images from the years 2000, 2009, and 2014 were classified with the decision tree classification method. On the basis of land classification results, the transfer matrix and landscape index methods were used to analyze the characteristics and the driving forces of landscape patterns at different times. The Markov model was used to predict the change of landscape pattern in the study area. The results show that with more construction land emerging around the water area, the landscape index I_NP increased from 7174 to 10334, I_C decreased from 64. 5944 to 63. 6515, and landscape fragmentation increased, enhancing the landscape heterogeneity. I_SHE and I_SHD increased slightly from 2009 to 2014, the agglomeration degree of landscape pattern increased, but showed a big gap with the level in 2000. Some natural wetlands were replaced by constructed wetlands, which resulted in the degradation of wetland ecosystem functions.