基于RS和GIS的乌伦古河流域植被覆盖度时空变化研究

Temporal and Spatial Variation of Vegetation Coverage in the Ulungur River Basin Based on RS and GIS

[目的]研究乌伦古河流域植被覆盖时空动态变化特征。[方法]选取乌伦古河流域为研究区,以6期(分别为1989、1998、2002、2006、2011和2015年)不同时相的遥感影像成果为数据源,采用像元二分法模型计算归一化指数(NDVI)来定量分析研究区1989—2015年植被覆盖面积的时空变化规律。[结果]从时间方面看,1989—2015年研究区的植被覆盖面积整体呈微弱减少趋势,减少了32.4 km2,年变化率为-0.01%;从空间方面看,研究区上、中游河段植被覆盖度波动变化较为频繁,主要表现在劣盖度与低盖度植被覆盖面积间的相互转变。[结论]该研究为合理开发利用乌伦古河流域水资源、保护并逐步恢复流域生态功能提供依据。

[Objective]The research aimed to study the temporal and spatial dynamic changes of vegetation coverage in the Ulungu River Basin.[Method]The Ulungu River Basin was selected as the study area,and the remote sensing image results of different phases in6phases(1989,1998,2002,2006,2011and2015,respectively)were used as data sources,and the normalized index(NDVI)was calculated by the pixel dichotomy model to quantitatively analyze the temporal and spatial variation of vegetation coverage in the study area from1989to2015.[Result]From the time point of view,the vegetation coverage area of the study area showed a slight decrease trend from1989to2015,which was reduced by32.4km^2,and the annual change rate was-0.01%.From the spatial aspect,the vegetation coverage fluctuations in the upper and middle reaches of the study area are more frequent,mainly reflected in the mutual change between the inferior coverage and the low coverage vegetation coverage.[Conclusion]This study provides a basis for rational development utilization and protection of water resources in the Ulungu River Basin,and gradual restoration of ecological functions in the basin.