Maximizing Water Productivity and Minimizing Virtual Water for Determining an Agronomic-Economic Program and Optimizing the Crop Production Strategy in the Sistan Region, Iran

Global warming and the loss of freshwater resources have turned attention to promoting crop water productivity by focusing on the role of crops’ embedded virtual water. Indeed, the production pattern based on maximizing water productivity and minimizing virtual water is gradually replacing the traditional patterns that were based on maximizing production and yields.

The present research aimed to present a cropping pattern and water allocation to crops and regions based on the virtual water scenario and water productivity. The research used a bi-level programming model (leader-follower) and applied the objectives of maximizing economic profit and water productivity and minimizing the Gini coefficient and virtual water to optimize irrigation water allocation among irrigated regions and crops and determine the optimal cropping pattern for crops in five regions, including Zabol, Zahak, Nimruz, Hamun, and Hirmand, for 2022-2023.

When virtual water and water productivity were considered, the system’s economic profit was estimated at 3.02 × 1013 IRR and 3.04 × 1013 IRR, respectively. Also, the highest water and cultivation area were assigned to melon and onion.

Considering the Virtual water content (VWC), less water was assigned to crops with higher Virtual water content, i.e., wheat and barley. When the water productivity index was considered, the results revealed that more water was allocated to crops with higher water productivity, such as melon and onion. The proposed model can be used to determine a cropping pattern that considers minimizing virtual water and maximizing water productivity as its objectives.