Spatial and temporal variation of vegetation cover in Hunan Province with multi-source data
Aiming at the profound impact of the dynamic change of vegetation cover on regional ecology and the urgent need to analyze its change rule in depth,this paper is based on the MODIS NDVI remote sensing data of Hunan Province from 2000 to 2020,combined with the meteorological data of the same period,and studied the temporal and spatial change of vegetation cover in Hunan Province through the methods of Hurst index,Sen+Mann-Kendall trend analysis,Pearson correlation analysis,etc.and proposed an attention mechanism CNN-GRU prediction model.The vegetation cover in Hunan Province from 2000 to 2020 showed a fluctuating growth trend,with a growth rate of 0.004 8/a in 21 a.The Hurst index was less than 0.50 and greater than 0.35,and the percentage of lakes with a Hurst index less than 0.50 and greater than 0.35 was 0.004 8/a.The vegetation cover in Hunan Province was 0.004 8/a in 21 a,and the percentage of lakes with a Hurst index less than 0.50 and greater than 0.35 was 0.004 8/a.The area with Hurst index less than 0.50 and greater than 0.35 accounted for 56.66％of the area of Hunan Province;the value of RMSE of the CNN-GRU vegetation cover prediction model based on the attention mechanism was 0.071 0,and the value of MAE was 0.059 5.The results show that most of the areas in H unan Province have a relatively stable and high vegetation cover,and the vegetation cover will show a slightly decreasing trend in the future,and the CNN-GRU vegetation cover prediction model based on the attention mechanism proposed in this paper will be able to predict the vegetation coverage in most areas of Hunan Province.The CNN-GRU vegetation cover prediction model based on the attention mechanism proposed in this paper is better than the GRU model and the CNN-GRU model in terms of evaluation indexes.
万方数据
维普
