Statistical Analysis of Conveyance Efficiency in Semi-Elliptical Prefabricated canalets and Earth Canals

The present study was conducted based on the results of field visits and data collection from different locations of modern distribution networks including tertiary and fourth degree channels as well as the traditional water distribution irrigation network in the cities of Khuzestan province in 2017. The lowest and highest distribution efficiencies were calculated at 46.88 and 99.69% in Baghmalek and Shushtar counties. The average distribution efficiency in all studied channels was 79.75%. The lowest distribution efficiency in teritary channel was 0.60 and the maximum distribution efficiency in fourth degree channel was 99.67%. This was while 36.4% of earthen canals had poor distribution efficiency. In this study, the values of distribution efficiency calculated in different canals showed that the type of ownership of canal is effective in increasing the distribution efficiency. In a way the average distribution efficiency in the canals covered by irrigation and drainage networks as non-personal channels were significantly different from the channels managed by the farmer (personal channels) at the level of 5%. Scientific management performed by irrigation and drainage networks in Khuzestan province caused about 60% of non-personal water distribution channels to have acceptable irrigation efficiency, while the lack of sientific management on personal canals (under Farmer management) including non-volume delivery of water due to mismanagement masurrement structures has caused about 85% of channels under farmer management do not have acceptable distribution efficiency.