关键词：
FY-3;MODIS;变异系数;一致性;稳定性
摘 要：
利用2014-2020年空间分辨率为250m×250m的MODIS和FY-3的NDVI数据,采用最大值合成法(MVC)合成MODIS和FY-3 数据集周、月尺度NDVI值,基于不同数据集月尺度NDVI最大值,分别计算其季节、年平均NDVI.采用数值对比、相关性和线性回归等方法,比较分析 2014-2020 年新疆区域FY-3 和MODIS NDVI 数据的一致性,讨论 FY-3 在新疆区域的适用性,并基于 FY-3 NDVI 数据,采用变异系数法研究2014-2020年新疆植被覆盖的变化.结果表明:2014-2020年新疆区域的MODIS NDVI的月均值普遍低于FY-3 NDVI,两种数据变化规律一致性较好,但月尺度NDVI在沙地、草地、林地、耕地、2017 年春季、2016年和 2018 年夏季、2015 年和 2019 年秋季及 2019 年冬季存在差异,差异区主要位于阿勒泰山区、伊犁河谷和天山东段.2020 年新疆区域各土地利用类型及季节的FY-3 NDVI均值高于MODIS NDVI均值,且FY-3 NDVI更接近实测值.新疆各土地利用类型及季节 FY-3 NDVI 数据的 R2、RMSE、MAD、RE、残差(θ)均低于MODIS NDVI,表明FY-3 数据趋于集中,在新疆区域稳定性高于MODIS.新疆区域植被NDVI季节和空间稳定性差异较大,季节尺度上夏季波动性较小,春、秋季波动性较大;空间上,草地、森林、绿洲农耕区植被覆盖状况越好,植被年际稳定性越强.
译 名：
Quality Evaluation and Applicability of the FY-3 NDVI Dataset in Xinjiang Region
关键词：
FY-3%MODIS%Coefficient of variation%Uniformity%Stability
摘 要：
In this paper,the reliability and accuracy of the FY-3 and MODIS NDVI data in Xinjiang from 2014 to 2020 was analyzed by using numerical comparison,correlation analysis and trend consistency analysis,and the reliability and accuracy of FY-3 and MODIS were studied.Based on FY-3 NDVI data,the vegetation change in Xinjiang from 2014 to 2020 was studied by using coefficient of variation analysis method.The results show that the MODIS NDVI monthly mean from 2014 to 2020 were generally lower than those of FY-3,however,the change rules of the two sets of data were consistent,but there were certain differences in NDVI between the two data in sandland,grassland,woodland,cultivated land,spring 2017,summer 2016 and 2018,autumn 2015 and 2019,and winter 2019,the difference areas were mainly located in Altai mountain district,Ili river valley and the eastern section of Tianshan mountains;in 2020,the average NDVI data for each land use type and season in FY-3 was greater than the average MODIS NDVI data,and the FY-3 NDVI data were closer to the true value.At the same time,the NDVI data R2,RMSE,MAD,RE,θ for each land use type and season in FY-3 were lower than the MODIS NDVI data,indicating that the FY-3 data tends to be concentrated,with higher stability than the MODIS data,the NDVI data of FY-3 superior to MODIS NDVI.In Xinjiang,the internal stability of vegetation varies greatly seasonally and spatially,with small fluctuations in summer and large fluctuations in spring and autumn on a seasonal scale.Spatially,regions with better vegetation coverage,such as grasslands,forests,and oasis farming areas,have stronger internal stability of vegetation,and vice versa.
