Investigation of Irrigation Systems Development, Cropping Pattern Scenarios, and Deficit Irrigation on Water Productivity in Qazvin Irrigation Network by Systems Dynamics

One of the most critical challenges of the twenty-first century is to resolve water crisis. This crisis is characterized by scarcity of water, the destruction of natural ecosystems, and food shortages. In spite of extensive efforts made to ensure food security, human societies still have trouble feeding their populace. This problem is most likely due to their inability to access healthy and safe water resources (Kijne, 2003). The solution to the water crisis can be expressed as better development and proper management of water resources systems. Various technical and managerial solutions should be taken such as upgrading and improving irrigation systems, introducing new irrigation methods, deficit irrigation, optimizing the cropping pattern, improving the efficiency of irrigation networks, etc. to improve water productivity in agriculture. The system dynamics methodology is a modeling and simulation technique and is specially designed for long-term, chronic, and dynamic management issues (Vlachos et al., 2007). Crop pattern scenarios, crop production, and agricultural pollution in a region in southern Turkey have been studied by Saysel et al. (2002) with a system dynamics approach. Also, the system dynamics approach was applied in the study of integrated water management at the catchment scale by Soltani and Alizadeh (2017). In this study, the systems dynamics approach, which is a suitable method for studying complex water systems, was applied in water productivity investigation in the Qazvin irrigation network.