2004 Volume 17 Issue 3 Pages 252-263
To examine the effects of the bedrock fissures and bedrock subsurface flow on runoff generation mechanisms, a large-size sprinkling experiment was conducted and the numerical analysis was developed. The experimental slope with 6.25m long, 1.5m wide and 30 degrees has three fissures with openings of 2.5cm × 17cm in the middle part of the slope. The 80cm × 110cm × 80cm storage tank was installed under the experimental flume, which was connected from the experimental flume through simulated “fissures”. The infiltrated water and tank water outflow was monitored. The finite element analysis was developed to simulate the bedrock recharge and outflow. The lag time between rainfall peaks to runoff peaks were found to be longer in the case of no tank infiltration than the experimental cases with infiltration to the tank, in which the runoff from the soil coincides with rainfall peak, but the runoff peak from the tank was delayed to the rainfall peak. Compared with the numerical analysis and experimental results, infiltration into the bedrock and the runoff from the bedrock would play important roles for the runoff generation mechanisms.
