Complexity modeling and sensitivity analysis considering topographic features

Due to the absence of a standardized terrain complexity definition, representative landform areas were selected. The correlation coefficients of the terrain factors were calculated using 30-metre Copernicus digital elevation model (DEM) data, and optimal model parameters were determined through factor analysis, resulting in a comprehensive terrain complexity model. The study shows that:(1) Multi-scale Terrain Complexity Index (MTCI) values below 0.1 correspond to plains or basins, values between 0.1 and 0.8 represent hilly terrain, values from 0.8 to 2.0 indicate plateau terrain, and a MTCI of 2.0 or above signifies mountainous terrain; (2) Terrain complexity exhibits a positive correlation with elevation and the scale of mountains; (3) Sensitivity analysis indicates that the terrain cut depth is a key reference indicator for model optimisation and uncertainty assessment. Consequently, study offers valuable insights for topographical, ecological assessments, regional development, and related fields.