Fig. 1

Study area. The left map was generated by Basemap (Version: 1.4.1, https://matplotlib.org/basemap/stable/users/introduction.html), and the right vector data was sourced from the National Geomatics Center of China through Tianditu (approval number GS(2024)0650, https://cloudcenter.tianditu.gov.cn/administrativeDivision).