Subsurface flow is an important form of water flow in slope cropland of purple soil area

while rainfall intensity is the key factor to control subsurface flow and soil water content. In order to understand the impact of rainfall intensity on soil water and subsurface flow at different layers of purple soil depth and to discover the correlation between water content and interflow in purple soil area

Minitrase TDR probes were buried into purple soil profile

which included superficial layer (0—20 cm)，middle layer (20—40 cm) and deep layer (40—60 cm)

to continuously measure soil moisture content in situ under the conditions of three simulated rainfall intensities (60 mm/h

90 mm/h and 120 mm/h). During the simulated rainfall process

the precipitation-runoff-producing was observed by collecting different layers’ interflow. The results indicated that: (1) When the simulated rainfall intensity was small

the changes of soil water content in superficial layer showed a trend of from rising to stability. Then along with the increasing rainfall intensity and soil depth

it presented rising

stable or always stable state. (2) As the soil depth and rainfall intensity increased

the response of soil water content to rainfall intensity was not obvious

with an increasing stabilization time and little change in soil water content. (3) The presence of various levels of interflow was observed in all layers under different rainfall intensities. Subsurface flow producing presented an unimodal process under low rainfall intensity conditions

otherwise

it had double peaks. (4) The producing time of interflow declined significantly with higher rainfall intensity

and increased with deeper layers. (5) It could be concluded that rainfall intensity had obvious correlations with soil water content and subsurface flow.