Evaluate the performance of subsurface drainage to control water level and salinity in agricultural lands of hamidieh based on RGWD and SEI

The research in the fields of irrigation and drainage network in the province Hamidieh to evaluate the performance of drainage was done in the land. For this purpose, three drainage server farm at intervals of 50, 70 and 80 meters in the area was selected. Blank observation on three drain pipes at intervals of 0.3,0.8,1.5,2.5 and 15 meters of lateral drains in the middle of the line in four rows (1/4 L, 2 / 4L, 3 / 4L and 25 meters of drain output) has been installed.After drilling, construction and equipping of wells observed three times a day, after watering irrigation, the water level in the wells was read. Sampling was conducted at each irrigation water and the electrical conductivity (EC) were measured and recorded at every turn. Discharge is also the entrance to the farm was measured in each irrigation. The average hydraulic conductivity field and in the fields as well as 0.69, 1.04 and 1.13 respectively. Drainage coefficient measured at the research farm (First farm 2.08, 2.27 and second field 2.74 third farm millimeters per day), respectively.According to the drainage and water table RGWD index was specified, desired lateral in each field, in controlling water table have performed well. In the fields of lateral discharge from 1.08 to 0.03 liters liters per second per second is variable within 8 days after irrigation and drainage water salinity is variable from 20.5 to 11.1 dS m. SEI index was negative in all three fields with average value of -1.20 in the first field, -2.50 in the second field and -2.70 in the third field. This indicates proper operation of drainage system in the salt out of the root zone. According to estimates from different formulas drainage water table level in comparison with the measured unsteady and it was concluded pig farms that The mean relative error in measuring the high water table drainage in DummFormula on the basis of the lowest relative error was. And thus measured values pig breeding farms in accordance with the formula for more. The level of 0.3 meters at a distance of around drains underground water table, water table is evident steeper slope. And this represents an increase in the hydraulic conductivity is close to underground drains.So filters are artificial drainage has good performance. RY product performance index for a 0.88 first farm,  secondfarm to  third farm between 0.78 and 0.83 has been estimated.The second-lowest first farm and field's relative performance.