نوع مقاله : مقاله کامل علمی پژوهشی
نویسندگان
1 نویسنده مسئول، استادیار گروه مهندسی آب، دانشکده علوم و مهندسی کشاورزی، واحد تربت حیدریه، دانشگاه آزاد اسلامی، تربت حیدریه، ایران.
2 دانشجوی کارشناسیارشد مهندسی آبیاری و زهکشی، گروه مهندسی آب، دانشکده علوم و مهندسی کشاورزی، واحد تربت حیدریه، دانشگاه آزاد اسلامی، تربت حیدریه، ایران.
3 دانشآموخته دکتری مهندسی آبیاری و زهکشی، گروه مهندسی آب، دانشکده علوم آب، دانشگاه شهید چمران اهواز، اهواز، ایران.
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Background and Objectives: The industrialization of agriculture in most countries of the world and facing the problem of water scarcity has caused more control over water consumption; so that water can be used in the necessary amount and at the right time. Uniformity of water distribution is affected by wind speed and sprinkler operation pressure, which are the most significant climatic and system variables, and there is a correlation between these factors and the uniformity coefficient. On the other hand, measuring the uniformity coefficient in the farm is a difficult and time-consuming task. Therefore, developing mathematical models to investigate this correlation will be very efficient. The present research to achieve goals such as investigating the effect of wind speed, sprinkler operation pressure and the layout of sprinklers on the uniformity of water distribution, achieving mathematical models to determine the uniformity coefficient by usage several sprinkler pressures in different weather conditions, and finally providing scientific and practical solutions for Increasing the uniformity of water distribution in the farm was done.
The present research aims to achieve goals such as investigating the effect of wind speed, operating pressure and arrangement of sprinklers on the uniformity of water distribution, obtaining mathematical models to determine the uniformity coefficient by applying different sprinkler operating pressures at different wind speeds and Finally, scientific and practical solutions were presented to increase the uniformity of water distribution in the farm.
Materials and Methods: This research was carried out in the form of installing a single sprinkler a 33-meter square plot of land without vegetation, located in the research farm of Islamic Azad University, Torbat Heydarieh branch, during the months of April to November of 2015. Three factors of wind speed (three levels: 0-5, 5-7 and more than 7 m/s), operating pressure (three levels: 2.2, 3.5 and 2.4 bar) and the layout of sprinklers (10 state: 12×15, 18×12, 18×15, 21×18, 24×21, 12×12, 15×15, 18×18, 21×21 and 24×24 m) as factors affecting The uniformity coefficient was investigated with three repetitions.
Results:The uniformity coefficient in wind speeds of 5-7 and more than 7 m/s decreased by 11 and 19%, respectively compared to the uniformity coefficient in wind speeds of less than 5 m/s. The area covered by sprinklers and their distances had more impact on changes in uniformity coefficient than wind speed. The highest uniformity coefficient was related to the layout of 18×12 and 18×15 m at a pressure 2.2 bar and a wind speed of less than 5 m/s. The decrease in uniformity coefficient caused by changing sprinkler layout was much less than the decrease caused by changing sprinkler distance. Also, the linear relationship between the uniformity coefficient and wind speed was evaluated in the range of pressure changes between 2.2 and 4.2 bar.
Conclusion: By examining various factors and according to the obtained results, it is recommended as a general result; In order to achieve a high uniformity coefficient by using the VYR 35 sprinkler at wind speed of less than 5 m/s from layout 12×18 m with pressure 2.2 bar, at wind speed 5-7 m/s from layout 15×15 m with pressure 3.5 bar, and in wind speed over 7 m/s, use 12×18 m with pressure 4.2 bar to be used. Of course, it seems more logical that in order to reduce the initial investment costs, the layout 18×12 meter to be used, and according to the prevailing wind speed in the region, pressure 2.2 bar for the wind speed less than 5 m/s and the pressure of 2.4 bar should be used in wind speed greater than 5 m/s.
کلیدواژهها [English]