Development of a Comprehensive Assessment and Risk Reduction Model for Urban Road Networks: A Case Study of Qom City

Road networks play an important role in emergency responses after an earthquake. The absence of an efficient road network can have significant consequences, resulting in a higher number of casualties and extensive damages, especially during the critical first 72 hours, generally known as the "golden time". Consequently, there is a fundamental need to develop management tools in order to minimize the risk to road networks in the event of an earthquake by implementing appropriate intervention measures prior to seismic events.

This study proposes a comprehensive model that assesses the risk associated with urban road networks, focusing on both physical and social parameters. The model incorporates four main risk indicators, namely hazard, vulnerability, response capacity, and performance parameters. By considering these indicators, a thorough evaluation of the risk levels can be obtained.

To demonstrate the practical application of the model, it was implemented in Qom City. The implementation led to the identification of high-risk zones within the city. Consequently, appropriate intervention measures were proposed and prioritized based on the assessment results. For areas prone to landslides, one of the suggested interventions was slope stabilization. Additionally, widening roads in zones with a high concentration of narrow paths and strengthening adjacent road structures were recommended. Implementation of these interventions resulted in an average risk reduction of approximately 12.2%, 7.4%, and 11.85%, respectively.

Importantly, the study also highlighted the absence of an emergency road network in Qom City. Recognizing this deficiency, the development of such infrastructure was identified as an effective intervention measure. The establishment of an emergency road network not only improves the response capacity but also reduces the overall risk in the study area by approximately 6.6%.

In conclusion, improving the management and risk assessment of road networks is crucial for effective emergency response following an earthquake. This research presents a comprehensive model that incorporates various risk indicators to assess urban road networks. The application of this model in Qom City allowed for the identification of high-risk zones and prioritization of intervention measures. The results emphasize the importance of interventions such as slope stabilization, road widening, strengthening of adjacent road structures, and the development of an emergency road network. Implementing these interventions can significantly reduce the overall risk and enhance the response capacity in the event of an earthquake.