Development of underground drainage method for prevention of suspended sediment runoff

摘要

In this study, we developed an underground drainage method for prevention of suspended sediment runoff from upland fields and examined the effectiveness of it by field experiments. In this method, an infiltration trench was made and water was drained by drainpipes through the infiltration trench. The trench was filled with aggregated soil from 2 mm to 20 mm in diameter. This method resulted in the drainage and filtration of water with suspended sediments. The suspended sediment runoff was very small in the early stages of the experiment, but this effect could not continue because of the formation of a crust in the later stage of the experiment. Tillage destroyed the crust, but it was not enough to restore the effect of the method. It was confirmed that there are some problems such as the control of crust formation and the restoration of the infiltration capacity.