基于Landsat数据的近30年东平湖湿地植被覆盖演变研究

Study of vegetation coverage change in the last 30years in Dongping Lake wetland based on Landsat data

以Landsat TM/OLI遥感影像为数据源,应用像元二分模型计算了东平湖湿地1985-2015年间7个时期的植被覆盖度,分析了其时空变化特征,并从人文活动特别是南水北调东线工程的方面探讨了植被覆盖变化的原因。结果表明:(1)近30年来,东平湖植被覆盖呈波动下降趋势,植被面积年均减少5.12km^2,并且中低覆盖度的植被区面积减少最为剧烈;(2)水域面积显著增加,由1985年的50.94km^2增加到2015年的101.73km^2,湖区裸地面积缓慢下降;(3)人类活动和南水北调东线工程的调蓄调水间接地改变了湿地植物的生境,导致植被分布格局和面积发生显著变化。

Dimidiate pixel model was employed to calculate the vegetation coverage of Dongping Lake wetland between sevenperiods from 1985 to 2 0 1 5 ,based on Landsat T M /O L I images.We analyzed the temporal and spatial variation of vegetationcoverage and human activities driving forces.Especially,the impact of South_ to_ North Water Transfer Project in E ast_ Routeon decrease of the coverage was discussed deeply.The results showed that; （1） in the past 30 years, the coverage reduced withfluctuation,with an average annual decrease of 5,12km2.The area with low coverage decreased dramatically,（2） The water areaincreased significantly from 50.94km^2 in 1985 to 101.73 km2 in 2 0 1 5 . Bare land area reduced slowly.（3） Human activities andthe South -to-North Water Transfer Project in East -Route indirectly changed wetland plant habitats？resulting in the changeof vegetation distribution pattern and ranges.