中文摘要：

【目的】分析中国西北地区植被覆盖变化情况及其与气候因子的关系,为改善区域生态环境提供参考。【方法】利用GIMMS/NDVI数据,采用NDVI均值法、差值分析法以及相关分析法,对西北地区植被覆盖时空变化及其与气温和降水的关系进行分析。【结果】植被覆盖增加的区域主要有：新疆的天山、塔里木河流域、青海的东南部、甘肃的中东部、宁夏部分地区以及陕西省等地区,植被覆盖减少的区域主要分布在：新疆塔里木盆地、昆仑山、甘肃西北部以及宁夏和甘肃交界处等地。植被NDVI与年际温度呈显著的正相关性,并且与年内气温、降水量和积温存在极显著的相关性,相关系数分别为0.890、0.900和0.442。【结论】1982—2006年西北地区植被NDVI呈增加趋势,增速为0.4%/10 a,植被覆盖变化与年内气温和降水量的相关性显著,并且植被变化对气温和降水的响应存在时滞。

英文摘要：

【Objective】 This article aims to analyze the change of vegetation coverage and its relationship with climate factors in northwest China,to provide reference for the improvement of regional ecological environment.【Method】 Based on GIMMS/NDVI data,the spatial and temporal change of vegetation coverage and its relationship with temperature and precipitation by using mean NDVI,difference analysis,and correlation analysis were analyzed.【Result】 The increased regions of vegetation coverage mainly include： Xinjiang Tianshan,Tarim river basin,the southeast of Qinghai Province,the central and eastern of Gansu,Ningxia and Shaanxi.The decreased areas are mainly distributed in Xinjiang Tarim basin,Kunlun mountains,northwest of Gansu,and the edge of Ningxia and Gansu.Vegetation NDVI is strongly positively related to annual temperature,and significantly correlated to month average temperature,precipitation and accumulated temperature,and the correlation coefficients are 0.890,0.900 and 0.442.【Conclusion】Vegetation NDVI increased in northwest during 1982-2006 with a growth rate of 0.4%/10 a,vegetation coverage change is significantly correlated to the month average temperature and precipitation,and the response of vegetation change to temperature and precipitation have time lag.