Effects of precipitation on soil moisture of micro topographies in the rainy season of the semi-arid Loess Plateau, China

In order to explore the differences in soil moisture replenishment from precipitation in the rainy season of the semi-arid Loess Plateau, China, we used a standard precipitation index to analyze the precipitation conditions from 1957 to 2011, and we analyzed the water supply characteristics of the soil in terms of the micro topography of the slope from 2008 to 2011 based on the precipitation data of a meteorological station in Wuqi County. The normal state and wet state had an increasing trend during the recent decade (20022011). The response of soil moisture in gullies, sink holes, ephemeral gullies, platforms and scarps to the precipitation of the rainy season was that the soil moisture in the normal state (2009 and 2011) was greater than that in the slight dry state (2008 and 2010). The catchment effect of gullies, sink holes, ephemeral gullies and platforms was better than that of scarp and uniform slopes in the rainy season of normal state and slight dry year.