Spatial distribution characteristics of soil moisture in different slopes on Loess Gully Region

Abstract The spatiotemporal changes of soil moistures under different rainfall events and slope positions in the loess hilly and gully area were assessed in this study using the positioning monitoring method. According to the three positions with different distances from the top of the slope, set the three treatments of “top of the slope” (TS), “middle of the slope” (MS), and “bottom of the slope” (BS). The results demonstrated a certain degree of influence of rainfall and slope position on the vertical change of soil moisture at different soil depths in the study area. Before intense rainfall, soil moisture at different slope positions revealed a vertical distribution pattern and increased with increasing soil depth. In addition, soil moisture contents below the 60‐cm depth at different sites were significantly higher than those observed above the 60‐cm depth ( p < .05), while soil moisture contents below the 120‐cm depth were extremely significantly higher than those observed above the 120‐cm depth ( p < .01). On the other hand, no significant variation in soil moisture content was observed between different depths after intense rainfall events ( p > .05). The above studies show that soil moisture in the loess hilly and gully area has a certain hysteresis effect. The hysteresis of soil flow allows us to effectively collect and use soil moisture, which can provide a theoretical basis for the intensive and economical use of soil moisture in this area.