ObjectiveIn the Loess Plateau of northern China, rainfall is the main source of soil moisture due to limited amount of precipitation and strong evaporation. In the loess hillslope, rainfall would be reallocated depending on microtopography, that would affect soil water variation. Therefore, our study aimed to analyze the dynamics of soil moisture in different microtopography types, which can provide reference for the vegetation growth and restoration.

MethodIn this paper, soil moisture in the five microtopography types, e.g. platform, collapse, scarp, gully and shallow gully, was investigated in sunny slope of Hegou Catchment of Wuqi County, Shaanxi Province of northern China from August 2010 to June 2013. The self-correlation test, Mann-Kendall trend test, linear regression methods, etc., were used in this study.

ResultDuring the whole year and the growing season in the investigation period, the soil moisture content of microtopography increased with the increasing depth. Among them, the soil moisture content in the gully was relatively high, and in the scarp was the lowest. There was a significantly positive autocorrelation between soil moisture in each soil layers. The dynamics of soil moisture in the five micro-topography types during the investigation period was not significant. The soil moisture in each soil layer in the collapse had a slightly increasing trend, however, the soil moisture in other four microtopography types increased or decreased in each soil layer. The differences in changing rate of five microtopography types were also observed.

ConclusionOverall, during the monitoring period, among the five microtopography types, the soil moisture content in the gully was the highest, but the increasing rate of collapse was quicker.