Conjunctive Use of Surface and Groundwater Resources Using System Dynamics Approach: Case Study of Namroud Dam

Abstract

Integrated study of the surface and groundwater aids proper exploitation of the water resources of a region. In this paper, the results of ongoing research on conjunctive use of water from Namroud dam (Iran, Tehran, Southwest of Firoozkooh Village) and surrounding aquifers using system dynamics approach is presented. The impacts of dam construction on sustainability of groundwater resources of the region, as well as the operational management approach are studied using system dynamic approach. The method of system dynamics is a computer-aided approach to policy analysis and design. It applies to dynamic problems arising in complex social, managerial, economic, or ecological systems. In fact, any dynamic systems characterized by interdependence, mutual interaction, information feedback, and circular causality can be analyzed using system dynamics. The system dynamics approach emphasizes a continuous view. The continuous view strives to look beyond events to see the dynamic patterns underlying all events collectively. The continuous view focuses not only on discrete decisions but on the totality of policy structure underlying decisions. Events and decisions are seen as surface phenomena that ride on an underlying tide of system structure and behavior. The system dynamic approach is a useful tool often used in management and planning. The application of this tool in conjunctive use study of water resources of a region provides a practical model that can be used for any location in the world having similar conditions to that of the region investigated in this study. One needs to merely change the input data to that derived from the characteristics of the desired region. The simulation results in this study show that dam construction leads to overall decrease of groundwater availability over time, and potential aquifer storage loss due to consolidation of water bearing formations in the downstream regions. Analysis of integrated management alternatives can help the sustainability of the region’s water resources either by increasing irrigation efficiency, or by proper economic planning to adopt cropping practices with highest return. Three Indices (vulnerability, sustainability and reliability) were calculated for each of the four alternative scenarios.