Zahra Dehghan Manshadi; Parastoo Parivar
Abstract
Introduction: The management of social-ecological systems such as cities is extremely complicated due to the interdependence of subsystems, the cause-and-effect relationships that exist between them, and the impacts on sustainability. The necessity of ecological capacity and the ability of cities to ...
Read More
Introduction: The management of social-ecological systems such as cities is extremely complicated due to the interdependence of subsystems, the cause-and-effect relationships that exist between them, and the impacts on sustainability. The necessity of ecological capacity and the ability of cities to sustain their potential to provide goods and services to both current and future generations cannot be overstated. Understanding how arid ecosystems adapt to disturbances is critical for the sustainable management of such areas, given the global extent of this type of ecosystem and its fragility, both structurally and functionally. The purpose of this study is to assess the impacts of urban growth on the carrying capacity of Isfahan, which is located on Iran's central plateau. In this regard, simulation models can be an effective tool in providing scientific decisions in dealing with complex and unknown social and ecological systems.
Material and methods: In this study, system dynamics modeling was used to determine the cause-and-effect relationships between variables affecting Isfahan's carrying capacity. In order to examine the landscape structure, DIVISION, SPLIT, and IJI metrics have been used to show connectivity, and ED, SHDI, and AI metrics have been used to determine the heterogeneity of the landscape of Isfahan City. After problem articulation, the model boundary was defined in the initial step of the modeling process by developing the subsystem diagram. After the population, environment, landscape, and carrying capacity subsystems were evaluated, a cause-and-effect diagram was made. The flow diagram and scenario were also made to evaluate the state of Isfahan's carrying capacity. In order to validate the model, the historical trend and simulation of two variables of urban population and the number of industries have been compared using the coefficient of determination.
Results and discussion: The pressure factors on the urban carrying capacity were detected and analyzed by assessing key variables in the system, such as water sustainability (WSI) and air quality, as well as changes in the landscape structure of Isfahan using landscape metrics. The research findings indicate that approximately 90% of the urban water demand is dedicated to the domestic sector; therefore, the first scenario is related to the management of water consumption in this sector and its influence on the Water Supply–Demand Index. This scenario showed that if domestic water demand is not controlled, the result of this index will reach nearly 0.7 by 2040, indicating greater vulnerability to the region's water resources. The second scenario is related to the city's increasing trend of construction and the number of industries, the impact of which has been shown on the carrying capacity.
Conclusion: The current study's findings, based on two enlarged scenarios, demonstrated that water demand, changes in the structure of the urban landscape, and the growth of industries all have a major impact on Isfahan's carrying capacity. Therefore, by controlling and managing water consumption in the domestic sector, limiting industrial growth, preventing the destruction of gardens, enhancing urban green and open areas, and limiting the increase of impervious urban surfaces, Isfahan's carrying capacity will improve.
Zeinab Feizolahi; Mohammadreza Shahbazbegian; Seyed Abdolkarim Hashemi; Siavash Shayan
Abstract
Introduction: Lack of fresh water resources to meet water demand has been being looked on as a main challenge of dryland countries in the world. Iran is also suffering from the issue in particular at its sothern regions connecting to the sea. One of the main option on the table to tackle the problem ...
Read More
Introduction: Lack of fresh water resources to meet water demand has been being looked on as a main challenge of dryland countries in the world. Iran is also suffering from the issue in particular at its sothern regions connecting to the sea. One of the main option on the table to tackle the problem is water demand management has been bolded in Iran as water-related spatial planning scheme. As a result, in term of the water supply, the Minab plain is one of the most important region of the Hormozgan province in Iran and various economic sectors of the plain have been facing with many problems due to the lack of access to water resources. It is manifested by partial or no satisfaction of expressed demand, economic competition for water quantity or quality, disputes between users, irreversible depletion of groundwater, and negative impacts on the environment. In this regard, one of the most important policy option picked up to reduce these problems is the water-related spatial planning. Such approach focuses on spatial relationships and has been considered as an effective way to integrate economic, social and environmental programs into spatial development (Davies and Simonovic, 2011); In that piece, each region spatial organization crystallizes the flow and pattern of communication between different sectors in the region. But the traditional spatial planning approach, in terms of analysis, has been confining to tools such as GIS suffering from being mostly static and nonlinear. Material and methods: The main idea of the paper is that in water-related spatial planning studies, in addition to the traditional view, it is necessary to pay more attention to the system thinking so that the pattern of communication between different economic, social and environmental sectors could be related to water resources in dynamically and nonlinearly manner over time (Davies and Simonovic, 2011). Thus, in the present study, the given mechanism governing the important parts interacting with the water resources of the Minab plain as the spatial organization has been mapped through system dynamics principles, drawing a system mechanism. System dynamics is efficient knowledge to map and analysis following interactions among spatial organization attributes (Sterman, 2000). Results and discussion: Causal Loop Diagrams (CLDs) consisting of two kinds of Reinforcing and Balancing loops are being considered as the base of realizing structure of a system. In fact, the paper initiates to consider the spatial organization as a system to draw efficient policy options and discover complex interactions through it. That’s referred to the main principle of SD implying on structure of a system as a main reason responsible for its behavior. As result if we are going to analysis a spatial organization, considering it as a system, we need first to realize just its structure. To discover the structure, CLDs tool has been being introduced in SD (Richmond, 1993). Conclusion: Finally, apart from conventional policies around water supply, two policies based on water demand management approach have been extracted and discussed based on the performance of the given mechanism to maintain the spatial organization equilibrium of the Minab plain.
