辽河流域NDVI时空变化特征

Temporal and spatial variation of NDVI in LiaoHe Basin

利用辽河流域1982～1998年NOAA/AVHRR与1999-2007年SPOT VEGETATION的旬合成NDVI资料和35个站的逐日气象资料,分析了(归一化指数NDVI)的年内和年际变化规律以及NDVI与7个气候要素的相关关系。主要结论:辽河流域生长季NDVI呈逐步上升的趋势,增速为0.03/10a,生态状况在不断改善;辽河流域植被分布状况地方性差异较大,植被NDVI自西北向东南逐步增加,这与辽河流域由西北向东南水热条件逐步改善相一致。辽河流域2008-2010年平均NDVI变化率与1982-1984年间相比植被覆盖显著减少区域减少了16.50%,主要分布在流域北部草原与栽培植物区,这与流域日益改善生态状况相一致。辽河流域植被1982-2010年间NDVI显著增加最大的为夏季,其次为秋季,冬季最少,秋季很好的延续了夏季植被的长势。

Using NOAA/AVHRR 10 day composite NDVI data from 1982 to 1998, SPOT VEGETATION 10 day composite NDVI data and daily meteorological data at Thirty -five stations, the annual and interannual variations of NDVI and the relations between NDVI and seven climate factors were analyzed. The main results showed that NDVI increased significantly by a ratio of 0.03/10a during the growing season in Liaohe Basin, which ecological conditions was improving all the time ; Vegetation status of the Liaohe Basin owns large local differ- ences ,improving from northwest to southeast, which keeps the consistent with hydrothermal conditions gradually improved from northeast to southwest. Compared to NDVI rate of change from 1982 to 1984 , the area that vegetation cover reduced significantly reduced by 16.15% from 2008 to 2010 in Liaohe River Basin, mainly distributed in area of temperate grassland and Cultivated plants, which keeps the consistent with environmental conditions Improving day by day in Liaohe River Basin. The season that NDVI increased significantly from 1982 to 2010 was summer, followed by the fall, winter at least. Autumn was keeping Vegetation Growth on summer.