ارزيابي عملكرد سيستم زهكشي زيرزميني و مقايسه آن با زهكشي سنتي (جزر و مدي) در نخيلات آبادان

A Performance Evaluation of Subsurface Drainage System and Its Comparison with Traditional Drainage (Tide) in Date Palm Gardens of Abadan

The purpose of this research was an evaluation of the performance of subsurface drainage system in date palm gardens of Abadan. Four cases of drain envelopes including local gravel, standard gravel, and synthetic envelopes (polypropylene 700 and polypropylene 450) were employed and a comparison with the traditional drainage (tide) made. To achieve the purpose, 16 laterals (subsurface drains) installed in a 12 hectare area of date palm gardens in Irrigation and Drainage Project of Abadan Subsurface Drainage system were employed. Four laterals each equipped with one of the four different envelopes were constructed. In order to determine and evaluate hydraulic resistance, water table curves along with other parameters, a number of pizometers were either made connected to the drains or installed in between them at the distances of 0.25L, 0.5L and 0.75L (L is length of lateral). Parameters evaluated were: 1. Performance of subsurface drainage system for controlling water table and salt soil profile, 2. Design parameters of subsurface drainage system. Methods that present a better performance of controlling water table and salt soil profile in comparison with the traditional drainage (tide), were finally determined. With regard to all the results obtained and according to importance, the fallowing two acceptable methods are proposed: construction of subsurface drainage system using synthetic envelope polypropylene 450; construction of subsurface drainage system using standard gravel envelope.