Nader Salamati; Peyman Varjavand; Shokrola Absalan; Azarakhs Azizi; Moheydin Goosheh
Abstract
In order to optimize the efficiency of water in agriculture, it is necessary to know the extent of water leakage in the lined canals. In this study, water conveyance efficiency and seepage/leakage losses were determined to evaluate earth and concrete lined channels in Khuzestan irrigation networks. The ...
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In order to optimize the efficiency of water in agriculture, it is necessary to know the extent of water leakage in the lined canals. In this study, water conveyance efficiency and seepage/leakage losses were determined to evaluate earth and concrete lined channels in Khuzestan irrigation networks. The result of this assessment was to identify the problems of management and damages in these channels. Thirty channels were studied and evaluated in the main irrigation and drainage networks of Khuzestan province, including Karun, North Khuzestan, Karkheh, Shavour and, Zohreh and Jarrahi, and channels managed by the farmers. There were 17 tertiary and quaternary canals and 6 earth channels in irrigation networks, as well as 1 canal and 6 earth channels under farmers’ management. The water conveyance efficiency in canals ranged from 38.9% in Ramshir to 99.7% in Shushtar; and in the earth channels, from 46.9% in Baghmalek to 89.3% in Shush. The comparison of means of the measured and calculated indices was performed by t-test and showed that seepage per km length of the unlined earth canals was 3017.7 m3/day, which had no statistically significant difference with lined canals with a leakage of 2166.2 m3/day/km. The results of Pearson correlation coefficients showed that there was a negative and significant (at p<1%) correlation between distribution efficiency with the amount of seepage per kilometer channel length, and between losses and the input flow rate per km of channel length. Also, 16.7% of the total canals had a water distribution efficiency of less than 67.8% (between 38.9% and 67.8%), while 50% of the canals had a conveyance efficiency of less than 68.6%. The low water losses in half of the concrete lined canals and the excessive water loss in 11% of such canals, which even increased water losses in the earth's channels, reveals the necessity of paying attention to the optimal management of these canals. This optimal management should be considered at the design and construction stages of the structure as well as during the installation in agricultural lands. Attention should also be paid to use of proper seals and other suitable equipment to prevent water leakage.
n s; h d; a d
Abstract
Application of advance irrigation methods to a proper utilization of water resources is inevitable. The effects of different amounts of irrigation water on yield and quality of two varieties of date palm under asubsurface drip irrigation were studied in Behbahan Agricultural Research Station during two ...
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Application of advance irrigation methods to a proper utilization of water resources is inevitable. The effects of different amounts of irrigation water on yield and quality of two varieties of date palm under asubsurface drip irrigation were studied in Behbahan Agricultural Research Station during two growing seasons (2014-2015). The study was conducted in a randomized complete block design with a split plot design with three replications where three levels of water application based on T1=75%, T2=100% and T3=125% of crop water requirement, were as the main plots and two variety of Khasi and Zahedi were as sub-plots. The results showed that different levels of irrigation have not had no significant effect on the quality and yield of fruit. However, there was a significant difference (p<0.01) between the levels of irrigation in terms of water use efficiency. Accordingly, T1 by 0.88 kg of dates per cubic meter of water showed higher water use efficiency. Comparison of mean interactions between the water application and varieties showed water use efficiency of Khasi and Zahedi varieties were 0.86 and 0.89 kg/m3, respectively. The applied irrigation water of palm trees based on T1 was of 7545 m3/ha which was 2515 m3/ha less compared to that under T2.