Table 1 Descriptions of geometric signatures used in this study
Geometric signature | Description |
|---|---|
lnSLOPE | Logarithmic value of slope gradient (degrees, add 1 to avoid logarithmic conversion of zero) calculated by SLOPE command of ArcGIS Spatial Analyst. |
lnHAND | Logarithmic value of HAND (meters, add 1 to avoid logarithmic conversion of zero) calculated by TauDEM (Tarboton 2005; Liu et al. 2016). D-infinity method (Tarboton 1997) was used to calculate flow directions. The threshold of extracting drainages was 150,000. |
TEXTURE | Density of pits and peaks extracted by 3 × 3 median filter with a radius of 10 cells (Iwahashi and Pike 2007). In this study, the threshold of pits and peaks extraction was set to 5 m to avoid DEM noise. |
CONVEXITY | Density of convex points extracted by 7 × 7 LOG filter with a radius of 20 cells. The window size has been enlarged compared to the original local convexity (Iwahashi and Pike 2007) to avoid DEM noise. |