Nader Naderi; Ali Ghadami Firouzabadi; Mahmud Froumadi
Abstract
Semnan province faces water and soil limitations due to its geographical location, desert and semi-desert climate. Pressurized irrigation methods are used as one of the options for improving water use efficiency in this province. In this study, sprinkler irrigation systems were evaluated in Semnan province. ...
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Semnan province faces water and soil limitations due to its geographical location, desert and semi-desert climate. Pressurized irrigation methods are used as one of the options for improving water use efficiency in this province. In this study, sprinkler irrigation systems were evaluated in Semnan province. For this purpose, 6 sprinkler irrigation systems including wheel move, classic with portable sprinkler, and center pivot systems were evaluated in different farms. Potential and actual application efficiency (PELQ and AELQ), uniformity, and distribution coefficients (CU and DU) for wheel move systems were 40.7%, 29.6%, 57.2% and 52.7%, respectively, and for classic systems with portable sprinkler they were 54.8%, 54.8%, 75% and 65%. For center pivot system, these parameters were 83%, 79.6%, 5/94%, and 91%, respectively. In center pivot system, these parameters were the best. Good designing, new and appropriate sprinklers, and low height of sprinklers were the factors causing better operation of this system. Next to center pivot, the classic system with portable sprinkler had better performance. New and appropriate sprinklers, low height of sprinklers, and appropriate pressure in this system increased the efficiency in farm No.4, while in farm No. 5, inappropriate sprinklers distance decreased efficiency of the classic system with portable sprinkler. In other farms, low pressure of sprinklers, decreasing the discharge and spray radius of sprinklers relative to nominal values and high pressure difference in the system caused low efficiency of wheel move system.
Nader Naderi; f a
Abstract
Qanat is one of the most surprising structures that is used for extraction of underground water in arid and semi-arid regions. There are 607 qanats in Semnan province, providing a total discharge of 93.5 million m3 of water per year. In this research, existing conditions and irrigation in agricultural ...
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Qanat is one of the most surprising structures that is used for extraction of underground water in arid and semi-arid regions. There are 607 qanats in Semnan province, providing a total discharge of 93.5 million m3 of water per year. In this research, existing conditions and irrigation in agricultural fields of 15 qanats of Semnan province were studied and some executive strategies were recommended to improve qanats’ performance. , quantity and quality changes of qanat water, application efficiency and water productivity downstream the studied qanats were evaluated. Results showed that insufficient credit, tunnel and wells collapsing due to lack of necessary construction and resistant covering, entrance of flood into qanats, numerous owners and rural migration were the most important reasons of discharge reduction and qanats destruction. Variations of EC and pH in qanats water were relatively low for a long period of time. Average of application efficiency in cultivated lands downstream the studied qanats was about 51.6%. Whereas it was 45.5% downstream the studied wells in the same regions. Average water productivity for various crops was 0.63 kg/m3. Establishment of strong groups to better partnership of owners in operation and maintenance of qanats, regular dredging, tunnel staining, well covering, tunnel tubing and fixing valve in qanat outlet, construction of qanat water reservoir and establishment of proportion between crops water requirement and amount of irrigation water in downstream lands of qanats are the most important practical strategies for improving qanats conditions.