Document Type : Original Article
Author
Associate Professor, Agricultural Engineering Research Department, Fars Agricultural and Natural Resources Research and Education Center, Agricultural Research, Education and Extension Organization(AREEO), Shiraz, Iran. mashahrokh@yahoo.com
Abstract
Extended Abstract
Introduction
Many of irrigation and drainage systems in the world have poor performance or efficiency. Evaluation of irrigation and drainage systems may help managers to find managerial and technical problems. Some researchers have developed evaluation indicators for quantifying the irrigation systems characteristics. Molden and Gates (1990) extended four water delivery performance indicators based on the adequacy, efficiency, equity and dependability of water delivery. These water delivery performance indicators have been widely used over the world until now. A problem with these indicators was the final judgment about the overall performance of the system when some of these indicators show good and the others show the poor performance of the system. Shahrokhnia and Olyan-Ghiasi (2019) found a solution for this problem extending an overall water delivery performance including the four previous indicators. Water delivery performance in Doroodzan Irrigation Network has been controversy between farmers and managers. In this study the overall water delivery performance indicators were measured based on the previously extended indicators in Doroodzan Irrigation Network and discussed.
Methodology
For evaluation of water delivery performance in Doroodzan Irrigation Network, the water delivery information in four years during 1993 to 2015 were used. The overall water delivery performance indicators which calculating based on adequacy, efficiency, equity and dependability of water delivery, were measured and evaluated. A new water delivery performance indicator named “summation water delivery performance indicator” was also extended in the present study and used for the evaluation of water delivery in Doroodzan Irrigation Network. The two overall indicators, overall water delivery performance indicator and summation water delivery performance indicator were used and compared for evaluation of some of the other irrigation and drainage schemes over the world.
Results and Discussion
The average of the four years measured indicators (during 1993 to 2015) for Doroodzan irrigation and drainage network showed that the adequacy of water delivery was about 0.79 which was categorized as poor, also was near the border value 0.80. The efficiency of water delivery was equal to 0.85 which is exactly the border value between fair and good category. The equity and dependability of water delivery were equal to 0.43 and 0.30, respectively, both stood on the poor class of performance. Therefore, the overall water delivery performance indicator and summation water delivery performance were equal to 0.73 and 0.91 which stay on the poor class of performance. It can be concluded that the overall performance of water delivery in Doroodzan irrigation network had been poor during past 22 years period of study. The overall water delivery performance indicator in related four main canals MC, RBPC, LBPC and RBSC were about 0.74, 0.75, 0.67 and 0.73, respectively. The summation water delivery performances of thosefour main canals were 0.95, 1.01, 0.69 and 0.90, respectively. The amount of overall and summation water delivery performance indicators in the main canals of the system showed that the main canals MC, RBPC, LBPC and RBSC also stay on the poor class of performance for the studied time period.
Conclusions
The four major water delivery performance indicators adequacy, efficiency, equity and dependability have been successfully used for the evaluation of irrigation and drainage networks, worldwide. However, they are some separate indicators and shall be used together for the better evaluation of the systems and related judgments. The recently developed indicator (overall water delivery performance indicator) and the new indicator developed in the present study (summation water delivery performance indicator) which are based on combination of adequacy, efficiency, equity and dependability, were used for overall evaluation of Doroodzan irrigation network and some others over the world. Doroodzan irrigation network and the four related main canals stood on poor category of performance over past 22 years period of study. The variation range of summation water delivery performance indicator is zero to 2 which is wider than the variation range of overall water delivery performance indicator (zero to 1). Therefore, the summation water delivery performance indicator can be better than the overall water delivery performance indicator to compare the irrigation systems that have little
performance differences. The summation water delivery performance indicator is simpler than the overall water delivery performance indicator in shape and calculation.
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