Research on the applicability of three vegetation indices based on MODIS data in vegetation monitoring of Hainan Island
Under the background of vigorously promoting the construction of ecological civilization,it is of great reference value to study the applicability of vegetation indices in vegetation monitoring in Hainan Island.Based on the NDVI(Normalized Differnce Veg-etation Index),EVI(Enhanced Vegetation Index),DVI(Difference Vegetation Index)data extracted from MODIS(Moderate-Resolution Imaging Spectroradiometer),monthly mean temperature and precipitation data of 18 national meteorological observation stations from 2001 to 2020 and land cover data in 2015 and 2017 of Hainan Island,the applicability of three vegetation indices NDVI,EVI and DVI in vegetation monitoring of Hainan Island was studied by using the univariate linear fitting,root mean square error analysis and correla-tion analysis method.The results are as follows:(1)Among the three vegetation indices,EVI has the best fitting effect on the vegetation coverage area extracted from the land cover data of Hainan Island,the root mean square error accounts for 9.57%of the actual mean.(2)EVI can best reflect the seasonal variation characteristics of vegetation in Hainan Island,it began to increase slowly in February,slow decline after reaching its peak in August,and fell to the lowest in February next year;EVI has the widest range,which can best re-flect the vegetation coverage with different thicknesses,and can better overcome the NDVI saturation problem in high vegetation area;EVI has the greatest correlation with climate factors and can best reflect the characteristics of vegetation′s response to climate.(3)The fitting effect of three vegetation indices on the vegetation coverage area of Hainan Island was comprehensively evaluated,and the ability to characterize the seasonal variation and density of vegetation was evaluated.The EVI was determined to be the most suitable vegeta-tion index for characterizing the vegetation characteristics of Hainan Island.
Hainan Islandvegetation indexesapplicability study
NETL
NSTL
万方数据
