Evaluation of Textile Filter in Field Drains
The role of drain in agricultural lands is to remove excess surface and subsurface water to create a good environment for root growth and to increase crops yield. The main objective of this research was to evaluate the performance of closed drains when using textile filter instead of crushed gravel filter. The research has been executed in the laboratory using a sand tank model and by using two types of the soil. One of soils was light soil (sandy soil) and the other heavy soil (loamy soil). The tests were classified into four cases; each case was supplied discharge during 10 days. The results showed that the amount of out flow when using graded crushed gravel filter is greater than the amount of out flow in case of using textile filter for the same soil; and the amount of sediment in applying graded crushed gravel filter for the two types of soils was greater than using textile filter. The entrance resistance for textile filter was greater than graded crushed gravel filter and the entrance resistance increase for the two types of filters with time. From the results it can be concluded that the graded crushed gravel is more efficient than the textile filter in sandy soil, while when using the two types of filters with loamy soil the results showed that the two types of filter exhibited low work efficiency.