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以2007年23时相MODIS增强型植被指数为数据源,利用决策树分类方法对海河流域生态系统进行了分类,分析了生态系统空间分布格局及其与地形因子的关系。结果表明:利用MODIS植被指数时间序列数据进行的生态系统分类,精度达到85.6%,Kappa系数为0.82。农田、城市和湿地生态系统分别占流域总面积的53.8%、1.0%和1.3%,主要分布在海拔<200m的平原;森林生态系统占22.5%,主要分布在500～1000m的低山;草地生态系统占21.4%,主要分布在1000m以上的区域。农田、城市和湿地生态系统主要分布在坡度<2°的地区,森林和草地生态系统主要分布在5°～15°的地区。随着坡度增加,农田、湿地和城市生态系统所占比例减小,森林生态系统所占比例增加,草地生态系统所占比例则先增加后减小。
Based on the MODIS Augmented Vegetation Index at 23 o’clock in 2007 as the data source, the classification of the Haihe River Basin ecosystem was classified by using the decision tree classification method. The spatial distribution pattern of the ecosystem and its relationship with the topographic factors were analyzed. The results showed that the accuracy of the ecosystem classification using MODIS vegetation index time series data was 85.6% and Kappa coefficient was 0.82. The farmlands, urban and wetland ecosystems accounted for 53.8%, 1.0% and 1.3% of the total basin area respectively, mainly distributed in plains <200m above sea level; forest ecosystems accounted for 22.5% of the total area, mainly distributed in the low mountains of 500-1000m; System accounted for 21.4%, mainly in the area above 1000m. The farmland, urban and wetland ecosystems are mainly distributed in the areas with slope of <2 °. The forest and grassland ecosystems are mainly distributed in the area of 5 ° ~ 15 °. With the increase of slope, the proportion of farmland, wetland and urban ecosystem decreases, the proportion of forest ecosystem increases, and the proportion of grassland ecosystem increases first and then decreases.