Although D-t and S-t have been restored for about three years,
soil indicators still showed significant differences compared to
those in D-ud and S-ud due to long-term effects of earthquake
damage (Cui et al., 2012). In physical properties, both disturbed and
treated sites (D-t and S-t) had higher sand and clay and lower SWC
and silt than those of undisturbed sites (D-ud and S-ud). This
means that the composition of soil particles has completely
changed because a weak weathered layer or strongly disturbed soil
layer replaced the well-formed soils in slopes by unconsolidated
materials’ movement (landslides, rock fall, and rock avalanches).
Subsequently, the disturbed soils became dry, resulting in the
reduction of SWC, which is similar to the changes occurring in
other areas where slope materials’ movement, debris
flow and
destruction of vegetative cover occurred after earthquake (Vittoz
et al., 2001; Cheng et al., 2012).