Systems Dynamics Model: the Resilience of Mashhad Plain to the Reduction of Underground Water Resources

Abstract

Abstract In many arid and semi-arid regions, underground water resources are considered the main source (or at least an important component) of fresh water supply. Because water scarcity and the occurrence of consecutive droughts are an inseparable part these regions and if they are not adapted, they can become one of the most catastrophic disasters. On the other hand, excessive extraction of underground water will cause a sharp drop and negative balance of water resources in these areas. Like many other parts of the world, Iran is also struggling with the problems of water shortage, so in most plains of Iran, such as Mashhad plain, which is one of the most important plains of Razavi Khorasan and is one of the plains prone to produce agricultural products, and like many plains of balance country the underground water in it is negative. Therefore, it seems necessary to pay attention to the resilience of underground water resources in the three sectors of agriculture, industry and household in this plain. In this regard, the main topic of this study is modeling the resilience of the Mashhad Plain to the reduction of underground water resources and providing effective policies and solutions to achieve a stable and resilient system. Therefore, to achieve this goal, the system dynamics model has been used because it is possible to examine different factors affecting resilience simultaneously in different dimensions. The results indicate that among the 46 variables, 14 variables have the greatest impact on the resilience of underground water resources, which are the criteria of groundwater consumption by farmers (0.979), groundwater consumption by industry (0.921), The volume of runoff (0.899), air temperature (0.893), and the amount of rain (0.890) are the criteria that have the most points in terms of influencing the water resilience. In this research, the policy of increasing the productivity index by 5% during the drought has the greatest effect on the resilience index, so that after a period of 6 years (in the year ending 2024), the resilience of underground water resources increased from 0.27 to 0.31 increases.