Optimization of Cultivation Pattern Based on Risk Management in the Downstream Irrigation Network of Ardabil Yamchi Dam

Cropping pattern optimization is an important strategy in the optimal use of water in agriculture. The present study attempted to develop and evaluate four hybrid models based on maximizing economic return rate and minimizing risk based on risk indices including variance (MVar model), semi-variance (MSVar model), absolute value deviation from mean (MADev model) and conditional value at risk (MCOVaR model). The MCOVaR model is governed by observing the rules, which at a selective confidence level allows determining the best cropping pattern scenario with selective return rate and the lowest risk that can be measured in the decision-making stage. The data used are related to the downstream irrigation network of Ardabil Yamchi Dam and for the 1397-98 crop year. The development of the model in MATLAB is based on nonlinear programming and optimization problem solving using particle swarm algorithm in a multi-objective solution. The highest correlation coefficient in regression of the models with Fourier equation was R2=0.9997 with accuracy (RMSE=0.0011) for MADev model, The results showed that the highest yield of 0.31 belonged to potatoes with a maximum risk of 58% and the lowest yield of 0.13 belonged to the maize plant with a maximum risk of 63%. By calculating 50 scenarios of the best possible cropping patterns in terms of satisfying the target functions and governing conditions, the pareto front of each model was drawn and the table of system income values for risk levels of 20% and 30% was extracted and presented. The results obtained in all models indicate an increase in economic efficiency by increasing the risk level of the system in selecting the optimal cropping pattern and this increase in MADev model is more steep than other models and increasing risk-taking leads to increasing the area under cultivation of plants with more water consumption.