归一化植被指数（Normalized Differential Vegetation Index， NDVI）是反映植被生长状态的重要指标， 是反映陆地生态环境状况的“指示器”。华北地区地处我国的政治和文化中心， 土地覆盖类型复杂多样， 是我国重要的粮食生产地， 同时受到气候暖干化及加剧的人类活动影响， 华北地区的植被生态变得十分脆弱。本研究基于卫星资料NOAA CDR AVHRR NDVI和气象数据资料， 采用趋势分析、 偏相关分析和残差趋势分析等方法， 探究了1982 -2019年华北地区NDVI的时空变异特征及其对气候变化和人类活动的响应。研究结果表明：（ 1）1982 -2019年华北地区春季、 夏季、 秋季和生长季的植被NDVI呈显著上升趋势， 空间异质性强， 其中夏季和生长季的增长速率最快为0. 024（10a）^-1 ， 显著增加的区域面积占 比分别为 57. 35% 和 58. 10%。（2）华北地区春季、 夏季和生长季 NDVI 与降水呈显著正相关关系， 秋季 NDVI主要受气温的影响， 夏季 NDVI同时受到气温、 降水和相对湿度的积极影响。（3）气候变化和人类 活动对华北地区植被的生长影响具有区域差异性， 在植被改善区， 气候变化的相对作用为 45. 64%， 人 类活动的相对作用为54. 36%； 在植被退化区， 气候变化的相对作用为32. 66%， 人类活动的相对作用为 67. 34%。（4）不同土地利用类型中， 华北地区森林和农田的植被生长较快， 其植被改善主要受人类活动 的影响， 人类活动的相对作用分别为66. 07%和60. 82%， 草地植被的退化也主要受人类活动的影响， 相对作用为69. 48%， 人类活动对华北地区植被的重要影响主要源于我国近几十年来三北防护林等人类重 大生态工程的建设以及城市扩张、 人口激增的影响， 该研究成果也对华北地区生态屏障的建设以及生态 环境保护提供了重要理论支撑。

The Normalized Differential Vegetation Index（ NDVI） is an essential index of vegetation growth status and an indicator of terrestrial ecological conditions. North China is China's political and cultural center， with complex and diverse land cover types， and is a critical agriculture production region in China. Meanwhile， the vegetation ecology in North China has become very fragile under the influence of climate warming and drying and intensified human activities. Based on satellite data NOAA/AVHRR NDVI and meteorological data information， this study explores the spatial and temporal variability characteristics of NDVI in North China and the effects of climate change and human activities on NDVI from 1982 to 2019 using trend analysis， partial correlation analysis，and residual trend analysis. The results showed that（1） The vegetation NDVI in spring， summer，fall，and growing seasons in North China from 1982 to 2019 exhibited a significant upward trend with strong spatial heterogeneity， among which the fastest growth rate of 0. 024（10a）^-1 was observed in the summer and growing seasons. The percentage of the area with significant increase was 57. 35% and 58. 10%， respectively.（2） NDVI in spring， summer， and growing seasons in North China displayed a significant positive correlation with precipitation， while NDVI in fall was mainly influenced by air temperature. NDVI in summer was positively affected by both air temperature， precipitation and relative humidity.（3） The effects of climate change and human activities on vegetation growth in North China have regional differences. In the vegetation increased areas， the relative role of climate change is 45. 64%， and the relative role of human activities is 54. 36%. In the vegetation decreased areas， the relative role of climate change is 32. 66%， and the relative role of human activities is 67. 34%. （4） Among different land use types， the vegetation growth of forest and farmland in North China is faster， and the vegetation improvement is mainly affected by human activities， the relative effect of human activities is 66. 07% and 60. 82%， respectively. The vegetation degradation of grassland is also mainly affected by human activities， the relative effect is 69. 48%. Human activities have an essential influence on the vegetation NDVI in North China， which mainly stems from the construction of major human ecological projects such as the Three North Protective Forests and the influence of urban expansion and population surge in recent decades in China， and the research results also provide necessary theoretical support for the construction of ecological barriers as well as ecological， environmental protection in North China.