Catchment area (A ; km²); maximum catchment length (HL ; km); catchment perimeter (Pe ; km); lemniscate ratio (LR ); compactness coefficient (CC ); form factor (FF ); height difference between the outlet and the highest point (HDC ; km); relief ratio (RR ); hypsometric integral (HI ). ns , not significant; ^**P < 0.01

TABLE 2 Land use/cover around the gully heads in 1957, 1972, and 2005