(4)
2.3.2. Determination and calculation of factors that characterize the topography
Topographic relief (Normark and Spiess, 1976), surface roughness (Romkens et al., 2002), surface cutting depth (He et al., 2016), and runoff path density (Zhao and Govers, 2016) were used to describe internal topographic characteristics of each runoff plot. The above indicators were calculated based on the measured topography data.
Topographic relief was calculated based on change-point theory. Firstly, the average value \(\overset{\overline{}}{X}\) was calculated according to the elevation value of 0.2m grid points {X1,X2,X3…Xn} in the runoff plot, and then the average topographic relief of the runoff plot could be calculated: