Identification of plastic film mulched farmland in the core area of the Beijing-Tianjin Sand Source Region using multi-temporal remote sensing features - Xialei Zhang; Jifeng Li; Huiru Li; Zhongling Guo; Chunping Chang; Xun Xu; Tianle Zhen; Kaixin Yu; Pengcheng Li (Remote Sensing Applications: Society and Environment, 2025)