Evaluation of Environmental Impacts and Economic Performance of Agricultural Water Distribution and Consumption Systems in Sefidrood Irrigation and Drainage Network

This study was done in Sefidrood Irrigation and Drainage Network. Paddy rice and tea gardens were selected as agricultural products. The environmental performance of the system was evaluated by selected environmental impacts categories such as climate change, Eutrophication, etc. Economic performance was also determined by using the total added value of the system's final products, according to water use and the adopted management practices. Finally, the value of area vulnerability was evaluated by assessing the eco-efficiency of these categories. The results showed that the most important environmental impact categories were climate change, human toxicity, aquatic eco-toxicity, and fossil fuels depletion because of high use of fertilizers and chemical pesticides, the combustion of diesel fuels in agricultural machinery and water pumps. So that the ratio percentage of the mentioned parameters were 48.9, 47.9, and 2.4% of the impact values of the climate change group, respectively. Furthermore, type I, II, and III indexes were defined for the environmental impact assessment of tea and rice, by which the tea indices were accordingly higher than those of rice due to their higher environmental impacts. For example, in the climate change group, the ratio of type I, II, and III indexes of tea to rice was calculated to be 1.4, 4.2, and 2.7, respectively. In addition, the economic performance of rice per hectare was approximately 70% more than the one of tea, however, the economic performance per cubic meter of water consumption in rice was only 8% more than the one in tea, due to high water consumption. Finally, the comparison of eco-efficiency indexes of different groups showed that the lowest eco-efficiency was obtained for climate change and fossil fuels depletion. In addition, the analysis showed that despite of the greatest environmental impacts of rice, the highest eco-efficiency index was related to rice due to higher economic performance compared to tea.