2010—2019年三亚市NDVI时空变化特征
Characteristics of NDVI Spatio-Temporal Changes in Sanya City from 2010 to 2019
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摘要: 归一化植被指数(NDVI)作为反映植物生长特征的重要指标,对于地表植被覆盖与植被生长状况的研究有重要意义。基于MODIS NDVI遥感数据,分析了三亚市2010—2019年归一化植被指数时空变化及变化趋势,并对NDVI与降水量和日照时数进行相关性分析。结果表明:近10年来,研究区NDVI月变化特征为5—10月增加,11月—次年4月降低,这与三亚市处于热带海洋性气候区有极大关系。NDVI年际变化呈增加趋势,年平均增长0.721 9,为中高植被覆盖度,空间上表现为北部高,中西部低的分布特征,北部常绿阔叶林地区比中西部草原地区生态稳定性更强。Pearson相关分析表明,NDVI与降水量整体上呈正相关,与日照时数呈负相关。Abstract: Normalized Difference Vegetation Index(NDVI)is an important indicator that reflects plant growth characteristics,and is of great significance for study of surface vegetation coverage and vegetation growth.Based on MODIS NDVI remote sensing data,spatial and temporal changes of NDVI in Sanya city from 2010 to 2019 were analyzed.Change trend and correlation between NDVI,precipitation and sunshine hours were also analyzed.Results showed that in the past 10 years,overall change in monthly NDVI of study area has been characterized by an increase from May to October and a decrease from November to April in next year.This has a great relationship with Sanya′s tropical marine climate zone.Interannual change of NDVI showed an increasing trend,with an annual average of 0.721 9,which was medium and high vegetation coverage,spatially showing distribution characteristics of high in the north and low in the central and western parts.Ecological stability of northern evergreen broad-leaved forest area was stronger than that of central and western grassland.Under Pearson correlation analysis,NDVI was positively correlated with precipitation as a whole and negatively correlated with sunshine hours.