Characteristics of NDVI Spatio-Temporal Changes in Sanya City from 2010 to 2019

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.