Journal of Urban Environmental Management

Abstract It is estimated that the Information and Communication Technology (ICT) industry is responsible for approximately 2 to 4 percent of the total carbon produced by human activities, which is equivalent to about 25 percent of total vehicle emissions and almost equal to the total carbon emissions of aircraft in the world. In the meantime, sixth generation (6G) communications play a major role in current and future ICT by providing high data rates for users and industries and have high energy consumption. On the other hand, due to high losses in 6G operating frequencies, the communication range is short and for maximum network coverage, many base stations (BS) are required, which both have high energy consumption and cause environmental pollution. To reduce energy consumption in wireless systems, especially 6G, reflective smart surfaces (RIS) have recently been proposed, which enable communication in blind spots with minimal energy consumption. This feature makes them a suitable option for improving energy efficiency in wireless networks. In this paper, the energy efficiency of 6G telecommunication systems at two mid-band frequencies of 7.8 and 15 GHz is investigated and calculated using RIS. The effect of path loss on signals is considered with real data resulting from the 3rd Generation Partnership Project (3GPP) standard, and the effect of the number of RIS elements, transmission rate, operating frequency, and other parameters in different scenarios is investigated. It is shown that the use of RIS can provide higher energy efficiency, which also increases with increasing frequency.

Abstract Urban waste management is one of the primary challenges faced by municipalities, especially in cities where informal flows play a significant role in the collection and recycling processes. This study aims to enhance the efficiency of the urban waste management system in Kerman by proposing a Causal Loop Diagram (CLD) model that focuses on the convergence of formal and informal cycles and the development of recycling industries. In the proposed model, the addition of recycling units such as aluminum, PET, plastic, and nylon recycling, alongside municipal recycling booths, increases the system's flexibility and creates economic added value. Moreover, through financial incentives, such as issuing permits and associated discounts, the model allows for the integration of informal waste collectors into the formal cycle, leading to increased municipal revenue from recycling and improved oversight of the waste collection and disposal processes. The results indicate that this model not only reduces the municipality's waste management costs but also contributes to urban sustainability by increasing informal collectors' cooperation and enhancing monitoring. Furthermore, recycling industries, as a critical part of the waste management chain, have the potential to convert raw waste into higher-value industrial materials, thereby boosting the system's economic and environmental efficiency. This model can serve as a blueprint for other cities facing similar challenges. Consequently, the present study offers an innovative approach, making strides toward the improvement and sustainability of urban waste management, which can enhance the efficiency and mitigate the problems of traditional waste management systems in Iran.

Abstract The purpose of this research was to identify and rank the drivers of environmental performance optimization and development of oil and gas refineries in the Republic of Iran using a strategic foresight approach. In terms of method, the present research is based on structural interaction matrix analysis with a strategic foresight approach and in terms of purpose, it is of a developmental-applied type. The statistical population of this research consists of 30 experts, including university professors and senior managers of oil and gas refineries in the Republic of Iran using a targeted method. The data of this research were collected through structured interviews and a qualitative questionnaire with a score from zero to three according to the structural interaction matrix and analyzed with the MICMAC statistical software. The findings of this study showed that the drivers of developing and implementing sustainable development plans in integrating refinery project processes, applying environmental standards in designing processes and operational units, training and developing environmental skills and competencies of human resources are influential drivers (influence). Also, the drivers of using renewable and clean energies in operational processes and production units, using a green approach in managing industrial waste and environmental pollutants, and modifying the energy consumption pattern in organizational and operational units of the refinery are influential drivers (dependent drivers). Finally, the drivers of upgrading air purification systems in refinery burners and exhaust chimneys are emphasizing the use of digital technologies in controlling pollution of production lines as independent drivers (eliminable drivers). The results of this study showed that identifying and ranking the drivers of optimization and development of environmental performance of oil and gas refineries in the Republic of Iran enables targeted allocation of resources, making strategic decisions, and employing effective technologies, and ultimately facilitates the movement towards sustainable development and compliance with international standards in the country.

Abstract The rapid growth of urbanization and increasing environmental pressures in Iranian metropolises have made it imperative to move towards smart cities with a sustainable development approach. The city of Tabriz, as one of the country's industrial and economic hubs, has faced challenges in recent decades such as air pollution, resource management weaknesses, and inefficiencies in environmental governance structures. This study aimed to conduct a structural analysis of the factors influencing smart environmental development in Tabriz. The research employed a quantitative method based on structural equation modeling (SEM) using the partial least squares (Smart PLS) approach. The statistical population included experts in urban planning, environmental studies, technology, and urban management. Using Cochran's formula for an unlimited population, a sample size of 200 experts was selected. Data were collected through a researcher-designed questionnaire and analyzed using Smart PLS and SPSS software. The findings showed that the factors of "smart waste management" with a path coefficient (beta) of 0.34, "technological infrastructure" with 0.31, "smart urban services" with 0.30, and "smart economy" with 0.26 had the most significant direct impacts on smart environmental development. The final model's coefficient of determination (R²) was 0.71, and the overall goodness of fit (GOF) was 0.50, indicating a highly desirable model fit. Additionally, the highest R² value was recorded for the "smart digital services" component at 0.76. The results of this study indicate that achieving smart environmental development in Tabriz depends on simultaneously enhancing technological capacities, improving environmental management systems, and promoting integrated data-driven urban governance.

Abstract Despite the existence of high-level policies and environmental regulations, Iran’s legal framework governing the oil and gas industry lacks institutional coherence and effective enforcement. This qualitative study employs Causal Loop Diagramming (CLD) to analyze the structural and behavioral dynamics of the current environmental regulatory system in this strategic sector. After reviewing key documents and extracting core variables, a CLD model representing the existing system was developed using Vensim software. The analysis reveals that the system is driven by reinforcing negative feedback loops—such as weak regulatory enforceability, institutional overlap, the prioritization of short-term economic gains over environmental obligations, and the absence of integrated performance indicators. These dynamics hinder the implementation of environmental laws even when formal policies are in place. Based on the systemic behavior observed in the model, the study proposes seven policy recommendations, including enhancing transparency, developing unified indicators, redefining institutional relationships, and strengthening expert and media capacities. The findings highlight that structural reforms are essential for achieving environmental sustainability in the oil and gas industry. Overall, this study demonstrates the utility of system dynamics modeling as an effective tool for identifying institutional bottlenecks and guiding the formulation of coherent environmental governance policies.

Abstract Abstract
The rapid pace of urban development and the increasing demand for construction projects in major cities have underscored the need to integrate environmental sustainability into project design and implementation. In this context, innovative geotechnical technologies have emerged as effective tools for enhancing the environmental performance of construction projects. This study aims to evaluate the impact of applying these technologies on key environmental sustainability indicators in urban construction projects in Tehran. Employing a mixed-methods approach, this research integrates qualitative and quantitative analyses. Initially, a systematic literature review identified relevant technologies and sustainability indicators. Subsequently, three major projects in Tehran were selected as case studies. Qualitative data were collected through 20 semi-structured interviews with key stakeholders and analyzed using thematic analysis in MAXQDA software. Quantitative data were extracted from project technical documents and analyzed through descriptive statistics. The findings reveal that the application of innovative geotechnical technologies has significantly improved soil and groundwater quality, reduced energy and resource consumption, and increased the use of recycled materials. Improvements in soil permeability (up to 75%) and reductions in nitrate concentrations in groundwater (up to 55%) were recorded in the case projects. However, challenges such as high initial costs, limited technical knowledge, and the absence of local standards were also identified. These results highlight the necessity of developing supportive policies, enhancing technical capacities, and establishing localized standards to facilitate the transition toward sustainable urban infrastructure.