System Dynamic Model For Foomanat Irrigation Network Improvement from Adequacy and Equity point of view

Major share of water resources are used for agricultural purposes. Irrigation networks، have important role in optimal use of water resources. Due to several factors many of the irrigation networks in Iran، are performing below expectations. Therefore performance improvement of irrigation networks and their rehabilitation is necessary. Due to the complexity of the problems of irrigation networks and the interactions between components، irrigation performance improvement، requires a comprehensive and prospective approach. One of the management tools for this purpose is dynamics system. In this research، Causal loop diagrams for Foomanat irrigation network are determined and conceptual model is developed. Afterward the quantitative model is developed and several rehabilitation policies are analyzed. The results suggest that if current processes are continue، the utility of irrigation network will decrease. It is shown that various policies can improve the network utility in different ratios. Among the individual policies the policies of investment for physical improvements and limiting the expansion of cultivated area have greater impact on network utility improvement in short-term and long-term respectively.