植被对调节流域水文过程、维持生态平衡具有重要作用，分析汉江上游植被变化和驱动因子具有重要价值。采用MODIS/Terra的NDVI数据和Land Cover数据分析了汉江上游不同土地利用类型的NDVI的变化规律，结合气象数据和DMSP灯光数据分析了气候变化和人类活动对植被NDVI的影响，分析了植被指数变化的主导性驱动因子。结果表明，2001－2017年汉江上游NDVI整体上呈增加趋势，年均NDVI介于0.5～0.62之间；同种土地利用类型的NDVI年际变化不大，不同土地利用类型的NDVI变化趋势基本一致，NDVI从高到低依次为落叶阔叶林、混交林、草地、农用地、灌丛、常绿针叶林。月平均最高气温是影响月NDVI变化的主导因子，夏季NDVI变化与日照时数和降水量关系较大，冬季NDVI变化与气温相关性较高。气温和降水与NDVI年变化的相关系数高于平均灯光强度变化，即年尺度上气象因素对植被变化的影响高于人类活动。

Vegetation plays an important role in regulating hydrological processes and maintaining ecological balance in the basin.It is of great significance to analyze vegetation changes and their driving factors in the upper reaches of the Han River.This paper uses NDVI data of MODIS/Terra and Land Cover remote sensing data to analyze NDVI changes of different land use types in the upper reaches of the Han River,and combines meteorological data and DMSP light data to analyze the impacts of climate change and human activities on vegetation NDVI,in order to find out the dominant driving factors of vegetation index changes. The results show that,the NDVI in the upper reaches of the Han River increased from 2001 to 2017,averaging between 0.5 and 0.62.The inter-annual NDVI variation of the same land use type was not significant.The NDVI change trends of different land use types were basically the same.The vegetation types sorted by NDVI from high to low are deciduous broad-leaved forest,mixed forest,grassland,agricultural land,dense shrub,and evergreen coniferous forest.The monthly average maximum temperature is the dominant factor affecting the monthly NDVI change.The summer NDVI change has a strong correlation with the sunshine hours and precipitation,and the winter NDVI change has a high correlation with temperature.The correlation coefficients of temperature and precipitation with annual NDVI change are higher than that of the average light intensity change.On the annual scale,meteorological factors have more influence than human activities on vegetation changes.

国家重点研发计划（2017YFC0405900;2016YFC0400906）；国家自然科学基金（51779203;51609270）