2.2 Data
The remote sensing image data (Table 1) included 0.5 m high-resolution satellite images (Digital Orthophoto Map, DOM) from 2009, 2012, and 2018 and 0.07 m high-resolution DOM images from 2021 by unmanned aerial vehicle (UAV). A total of 11,720 images were obtained from UAV. A DEM with 0.15 m resolution and DOM with 0.07 m resolution were created using Agisoft Metashape (Windows1.7.3). The 1:10000 DEM data used in this study were obtained from the Shaanxi Geomatics Center of the Ministry of Natural Resources, and the 0.15 m resolution DEM data were obtained by the authors using UAV.
Table 1 Details of the DOM and DEM data used in this study