使用像元二分法计算植被覆盖度。首先，基于掩模后的NDVI影像，统计5%和95%的像元值，带入像元二分法模型，进而计算植被覆盖度(Vegetation coverage was calculated by pixel dichotomy. Firstly, based on the masked NDVI images, 5% and 95% of the pixel values are counted, and then the pixel dichotomy model is introduced to calculate the vegetation coverage.)