Evaluation of the Center pivot system in different speeds Parallel and perpendicular to the water line

The Center pivot system is one of the most advanced sprinkler irrigation systems that recently has been used in Iran. According to this research on the compatibility of the system with the cultural, economic, climate and optimization performance of the system is essential. The importance of this matter on one side and the lack of information on the other hand, it highlights the need for an investigation. In this regard, the evaluation of the Center pivot system in two speeds 10 and 60 percent took a radial and vertical. The uniformity coefficient (CU) in the radial arrangement of cans and in two speeds 10 and 60 % was 80.3 and 76.4%, respectively and the uniformity of water distribution (DU) was 72.6 and 65.5 respectively. Also the uniformity coefficient (CU) in the vertical arrangement of cans and in the same speed was 61.1 and 59.3 % respectively. Uniform distribution of moisture in the soil after irrigation with rate of 60% was 86.37 percent. So the amount of Uniform distribution of moisture in the soil was higher than the uniformity coefficient in the Surface Soil (CU). The main reason is the horizontal flow and water transfer in the soil and its influencing factors (Mass flow, Diffusion and Hydrodynamic dispersion). According to this and given the lack of available water resources in arid and semi-arid area, maybe there is no need to increase water of irrigation in order to increase the uniformity of water distribution to more than 70 percent