The performance Evaluation of Travelling Gun Irrigation System implemented in Esmatyeh Farm of Qom

     One of the main purposes of sprinkler irrigation is the uniform distribution of water in the farm in order to supplying crop water and preventing wasting water. Travelling Gun irrigation system is a kind of sprinkler irrigation that is always mobile and irrigates farm in border-like manner. Esmatyeh Farm is one of the dedicated lands of Holly Shrine of Hazrat Fatemeh Masumeh where Travelling Gun irrigation system has been implemented. This irrigation system is 290-85 TX model with the diagonal of 85 mm Polyethylene and length of 290 m. The employed sprinkler is BIG GUN-SR 150 model, nozzle size of 17.8 mm made by NELSON Corporation. For the performance evaluation of this system, in the summer, June 2013, an investigation was carried out in two ways: Fixed Cart (3 repetitions) and Mobile Cart (4 repetitions). Therefore, coefficient of uniformity, distribution of uniformity, adequacy of irrigation, application efficiency of low quarter, application efficiency and wind drift and evaporation were determined. The results showed that in fixed Cart way, the deep of water on the ground decreases to the distance of 10 m from the Cart centre. Within the distance of 10-20 m from the Cart, the amount of water on the ground increases and will have the maximum amount in the distance of 20-30 m. The average of coefficient of uniformity in fixed Cart way was 61 percent and the average of distribution of uniformity was 44.8 percent. The average amount of water on the ground was 10.1 mm and the average of wind drift and evaporation in Trimmer method was 1.4 percent. In mobile Cart way, the difference between wind drift on the left and right side of the Cart indicate the effect of wind on the water distribution on the ground. The average of wind drift and evaporation in Trimmer method and fixed Cart way was 1.6 percent and in the mobile Cart way was 2.5 percent. The average of coefficient of uniformity was 65.1 percent and the average of distribution of uniformity was 48.3 percent which indicate that coefficient of uniformity is appropriate in Esmatyeh Farm. The average of distribution of uniformity in aforementioned farm is not appropriate and indicates of inappropriate of water distribution in the farm. The average of adequacy of irrigation was calculated as 66.7 percent. The average of application efficiency of low quarter calculated 24.7 percent and application efficiency was 48.8 percent.