The body of flow control system was constructed by a pilot
throttling valve with water-level feedback and a peristaltic pump.
The open and close of the spherical valve was used to control the
water discharge process. Flow rate changed with revolution speed
of the peristaltic pump. Calibration of flow rate was made manually
with scaled cylinder and stop watch at different outlet locations
according to relative elevation of slope segment. The minimum
control flow rate, which was 0.006 m3
/h, equivalent to 0.1 L/
min, could well meet the experimental requirement. A section of
flume was used to steady the flow velocity to insure uniform
distribution of melt water flow across the rill, so that water flow
was well distributed onto the soil surface uniformly and steadily
(Fig. 2).