基于PIE-Engine云平台的2018-2022年辽宁省植被覆盖度时空演变及影响因素

Spatial-temporal Evolution and Influencing Factors of Vegetation Coverage in Liaoning Province from 2018 to 2022 Based on PIE-Engine Cloud Platform

基于PIE-Engine(航天宏图)云平台,对2018—2022年辽宁省哨兵2A(Sentinel-2A)地表反射率数据进行处理,计算得到归一化植被指数NDVI,在此基础上利用像元二分模型计算植被覆盖度FVC,对计算得到的FVC结果运用趋势分析、偏相关分析等方法分析了辽宁省FVC时空演变情况及其影响因素。研究表明:1)2018—2022近5年辽宁省植被覆盖度FVC均值整体上呈波动上升趋势,植被覆盖度FVC均值由71.5%增至73.2%,其增长速率为2.3%。2)植被覆盖度FVC在空间上由西北向东北呈现逐渐递增的趋势,相比于退化地区的植被覆盖度提高的幅度大。植被覆盖度改善的区域明显大于退化区域,表明辽宁省植被覆盖情况得到恢复。3)相比较而言,高程和坡度是影响植被覆盖度FVC值的显著因子,FVC值随高程呈“下降—上升—下降”的变化趋势,同时FVC值随坡度的增加呈逐渐增加的趋势;4)FVC受气候的影响因素较大,3个气候因子与FVC有较强的相关性,年平均气温对FVC变化影响最大。

With the help of the PIE-Engine,the reflectance data of Sentinel-2A in Liaoning province from 2018 to 2022 were pro-cessed,and the NDVI was calculated.On this basis,the pixel dichotomy model was used to calculate vegetation coverage FVC,on this basis,using trend analysis,partial correlation analysis and other methods to analyze the spatio-temporal evolution of FVC in Lia-oning province and its influencing factors.The research shows that:(1)The mean value of vegetation coverage FVC in Liaoning prov-ince in the past five years from 2018 to 2022 showed a fluctuating upward trend as a whole,and the average value of vegetation cover-age increased from 71.5%to 73.2%,with a growth rate of 2.3%;(2)The vegetation coverage(FVC)shows a gradually increasing trend from northwest to northeast in space,with a significant increase in vegetation coverage compared to degraded areas.The area with improved vegetation coverage is significantly greater than the degraded area,indicating that the vegetation coverage in Liaoning province has been restored;(3)In comparison,elevation and slope are important factors that affect vegetation coverage FVC values.FVC values show a"descending ascending descending"trend with elevation,while FVC values gradually increase with increasing slope;(4)FVC is greatly affected by climate factors,and the three climate factors have strong significance with FVC.The annual av-erage temperature has the greatest impact on FVC changes.