Analysis of the effects of drought risk management using water productivity indicators

In recent years, with droughts and declining irrigation water, efficient use of water and water management has become inevitable. For this purpose, in this study, the risk effects of irrigation strategy in Qazvin plain in the 2015-2016 were analyzed. Initially, the percentage change in water quantity was calculated during the drought period. Then, using water-yield functions, deficit irrigation was applied to plants in four scenarios of 19, 32, 44 and 51% corresponding to the periods of weak, medium, severe and very severe droughts. Then, using the TM-PMP model, the risk effects of drought were investigated on the cropping pattern and water consumption productivity. The results showed that deficit irrigation increased the area under crops of wheat, barley and beans. This management strategy drastically reduces gross income by 24 percent in very severe drought conditions. Income risk is reduced by applying a deficit irrigation scenario during drought periods. Gross margin also decreases non-linearly as income risk. Water use efficiency decreased for wheat, barley, corn, tomato, maize and bean crops, and increased for beet and alfalfa crops. Therefore, if the irrigation strategy is implemented, the rate of income reduction in drought conditions will be 24%, but otherwise the income reduction will reach 58 percentages.