Investigating the effects of irrigation water and soil resources quality on the efficiency of Great Karun irrigation and drainage networks under uncertainty

Investigating the efficiency of irrigation networks is one of the most important factors in providing the necessary information to promote the performance of these systems and according to the recent water crisis, it should be considered by managers and planners of this field. This study has investigated the efficiency of four irrigation networks in Great Karun basin include Gotvand, Northeast of Ahwaz, the East of Shoeibeyeh and Myanab Shooshtar. One of the most important factors affecting the performance of these networks is the quality of soil and water resources. Therefore the efficiency of these networks was estimated under two scenarios of with and without considering water and soil quality. To conduct this study, a robust data envelopment analysis (RDEA) method has been used that has the potential to apply uncertain conditions for the input and output data of the model. The results showed that adding water and soil water quality data caused some of the seemingly inefficient networks to be significantly improved in efficiency score, and so the difference between rankings in two scenarios is very tangible. So that the average efficiency of networks is 0.8 in the first scenario and 0.97 in the second scenario. It was also found that there is a significant difference between the actual and optimal use for two input data of maintenance and personnel costs which has led to inefficiencies in networks. This difference was lower in the second scenario and was calculated for maintenance and personnel costs by 41 and 34 percent, respectively.Investigating the sensitivity analysis in the RDEA model showed that with increasing system protection against uncertainty, the efficiency score in the networks decreases.