基于连续时间序列NDVI数据的中国生态状况时空变化特征
宗加权1, 白淑英1, 冯朝阳2, 蒲 阳1

(1.南京信息工程大学, 南京 210044; 2.中国环境科学研究院, 国家环境保护区域生态过程与功能评估重点实验室, 北京 100012)

GIMMS NDVI3g; MODIS NDVI; 生态系统; 时空变化

Spatiotemporal Variation Characteristics of Ecological Status in China Based on Continuous Time Series NDVI Data
ZONG Jiaquan1, BAI Shuying1, FENG Chaoyang2, PU Yang1

(1.Nanjing University of Information Science & Technology, Nanjing 210044, China; 2.State Environmental Protection Key Laboratory of Regional Eco-process and Function Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China)

GIMMS NDVI3g; MODIS NDVI; ecosystem; spatiotemporal change

备注

植被是表征生态环境的重要指标,NDVI则是反映植被状况的重要指标,通过NDVI的时空变化特征可以揭示区域生态环境状况。基于1981—2015年的GIMMS NDVI3g和2000—2018年MODIS NDVI数据,利用二者相同时间段内的数据建立拟合方程,对1981—2000年GIMMS NDVI3g进行拟合修正,构建1981—2018年长时间序列的NDVI数据集,选择非耕地、非聚落地区和湿地等的NDVI,采用趋势分析方法分析中国近40年来NDVI的生态状况时空分布特征及变化规律,并统计分析不同生态系统类型的NDVI变化特征,用以反映中国近40年来生态状况的时空变化状况。结果 表明:除2000年、2001年,修正后GIMMS NDVI具有与MODIS NDVI相似的年份和月份变化规律; NDVI空间分布呈现东北(0.775)、中南(0.732)、华东(0.668)高,西南(0.485)、华北(0.471)、西北(0.275)低; 近40年来NDVI整体稳定; 森林和草地生态系统状况整体呈向好趋势; 荒漠、水体和湿地、其他生态系统的生态状况变差,NDVI下降趋势分别为:-0.000 6/a,-0.001 7/a,-0.000 7/a。研究为维护中国生态环境状况、保护生物多样性和开展生态环境评价提供决策支持。

Vegetation is an important indicator to characterize the ecological environment, and NDVI(Normalized Difference Vegetation Index)is an important indicator to reflect the status of vegetation. The spatiotemporal characteristics of NDVI can reveal the regional ecological environment. This study used the data in the same period to establish a fitting equation based on data production of GIMMS NDVI3g from 1981—2015 and MODIS NDVI from 2000—2018. We fitted and modified the GIMMS NDVI3g from 1981—2000 to construct a long-term sequence(1981—2018)of NDVI dataset. NDVI dataset was selected from non-arable land, non-settlement areas, and wetlands. We applied the trend analysis method to analyze the spatial-temporal distribution characteristics and changing patterns of NDVI's ecological status in China in the past 40 years. It also statistically analyzed NDVI of different ecosystem types. These change features can reflect the spatiotemporal variability of China's ecological status in the past 40 years. The results showed that the revised GIMMS NDVI data had a similar variation pattern with MODIS NDVI data on a year and month time scale except for 2000 and 2001; the spatial distribution of NDVI showed that NDVI value was high in the northeast(0.775), central south(0.732), and eastern china(0.668), and was low in the southwest(0.485), north(0.471), and northwest china(0.275); in the past 40 years, NDVI overall kept stable; the status of forest and grassland ecosystems presented a positive trend, but the ecological conditions from deserts, water bodies and wetlands deteriorated; the ecological conditions of other ecosystems have deteriorated, and the downward trends of NDVI are: -0.000 6, -0.001 7, -0.000 7 per year, respectively. This study attempts to provide decision-making support for maintaining China's ecological environment, to protect biodiversity, and to conduct ecological environment assessment.