Determining the effects of drain holes in different geometric shapes on flow and sedimentation

Agricultural lands, taking current conditions in consideration, should be used more efficiently, as well as benefitting from the inputs in agricultural production at the highest level. Drainage is defined as the removal of excess water from the soil surface or plant root zone that interrupts or stops the production of agricultural land, regardless of its source. In subsurface drainage systems, the first thing that encounters excess water in the field is the drainage holes on the collecting drains. Factors such as the geometric shapes, sizes, patterns and numbers of the drain holes affect the water flow into the systems. In this study, the effects of triangular, rectangular, square, and circular hole shapes with the same hole areas on drainage, and sedimentation under three different head with different hole numbers were determined in the laboratory using constant level permeameter method. The results obtained from this study indicated that the hole shapes and numbers affected the amount of water drained from the soil. Hole shapes showing the best performance according to the average flow rate drained from all water loads, were observed in square and triangle shapes. Independent of the hole shapes, the number of holes that discharge the highest amount of water was recorded in 6-hole plates. It has been observed that the hole shapes used in the study have an effect on sediment accumulation. The least sediment deposition was measured in the rectangular and triangular drain hole. It has been concluded that six triangular drain holes per unit area are suitable because they provide minimum sediment accumulation and maximum discharge.