1988—2018年粤北植被NDVI时空分布特征分析

Analysis of Spatiotemporal Distribution Characteristics of Vegetation NDVI in Northern Guangdong from 1988 to 2018

植被是陆地生态系统的核心组成部分,而归一化植被指数(Normalized Difference Vegetation Index,NDVI)是反映地表植被覆盖和生长状况的重要参数。以粤北为研究区,结合1988—2018年长时间序列NOAA/AVHRR产品数据和高程数据,采用变化率分析法和空间分析法,分析31年间粤北NDVI变化特征及其与地形因子的关联性。结果表明,1988—2018年,粤北NDVI年均值整体呈现出北高南低、西高东低的分布特征,NDVI年均值介于0.20~0.87。其中,连山壮族瑶族自治县NDVI年均值最高,达到0.82,而清远市清城区NDVI年均值最低,仅为0.68。2018年,NDVI年均值达到最高,为0.84;1988年,NDVI年均值达到最低,为0.74。随着高程的增加,粤北NDVI年均值呈现出上升趋势,NDVI分布特征受到人类活动、地形和气候的综合影响。研究结果可为粤北山地城市生态屏障区建设提供重要理论支持。

Vegetation is a core component of terrestrial ecosystems,and the Normalized Difference Vegetation Index(NDVI)is an important parameter reflecting surface vegetation cover and growth status.Taking northern Guangdong as the research area,combined with long-term NOAA/AVHRR product data and elevation data from 1988 to 2018,this paper uses rate of change analysis and spatial analysis methods to analyze the characteristics of NDV Ichanges in northern Guangdong over the past 31 years and thei rcorrelation with terrain factors.The results show that from 1988 to 2018,the annual average of NDVI in northern Guangdong showed a distribution pattern of high in the north and low in the south,and high in the west and low in the east,and the annual average of NDVI ranged from 0.20 to 0.87.Among them,the annual average of NDVI in Lianshan zhuang and yao autonomous county is the highest,reaching 0.82,while the annual average of NDVI in Qingcheng district,Qingyuan city is the lowest,only reaching 0.68.In 2018,the annual average of NDVI reached its highest level at 0.84;in 1988,the annual average of NDVI reached its lowest level at 0.74.As the elevation increases,the annual average NDVI in northern Guangdong shows an upward trend,and the distribution characteristics of NDVI are influenced by a combination of human activities,terrain,and climate.The research results can provide important theoretical support for the construction of ecological barriers in mountainous cities in northern Guangdong.