Evaluation and Zoning of Earthquake Hazard Using Fuzzy Hierarchical Analysis Approach(FAHP) (Case Study: Hormozgan Province)

Earthquake is one of the inevitable natural disasters that, if it occurs, causes countless damages and problems for the economy, environment and human life. Therefore, earthquake crisis management is essential. Experience has shown that preventing the occurrence of a crisis is better than organizing it after it occurs. Therefore, the phases before the crisis in the crisis management cycle are of particular importance.Iran's strategic geographical location positions it susceptible to substantial seismic activity, establishing its standing as one of the most earthquake-prone nations globally. The convergence of the Alborz and Zagros mountain ranges has increased this susceptibility, notably due to the interaction of the Saudi plate with the Zagros range, thereby causing seismic hazards for various urban centers located in close proximity to fault lines and mountainous regions. Identifying areas prone to these environmental hazards is fundamental as a primary measure in implementing effective risk mitigation strategies, urban planning initiatives, and construction endeavors. Therefore, the present investigation was conducted to evaluate and map the seismic vulnerability of Hormozgan province, with the objective of pinpointing and categorizing high-risk zones within the province.

Hormozgan Province is situated in the southern region of Iran, positioned to the north of the Strait of Hormuz. Geospatially, the province spans from approximately 25 degrees and 25 minutes to 27 degrees and 18 minutes north latitude, and 52 degrees and 39 minutes to 59 degrees and 14 minutes east longitude from the Prime Meridian. With a land area of around 71,193 square kilometers, Hormozgan Province encompasses about 3.4% of Iran's total land area and comprises 13 cities, 39 districts, 88 villages, and 50 townships.This study utilized ArcMap software to analyze earthquake data from the past 20 years. They created maps for factors like earthquake magnitude, depth, and proximity to faults. Additionally, density maps for both faults and historical earthquake epicenters were generated. After processing the data and assigning weights using expert opinions through Fuzzy AHP, the software combined these layers to produce a final map that zones earthquake hazard levels across the region.As aforementioned, the research methodology employed in this study involved the integration of fuzzy logic models and hierarchical analysis within a Geographic Information System (GIS) framework to assess the seismic vulnerability of Hormozgan province to earthquake risks.The Fuzzy Hierarchy Analysis Method (FAHP) incorporates fuzzy logic concepts into hierarchical frameworks to accommodate subjectivity in complex decision-making. Through the hierarchical arrangement of decision-making criteria and the use of fuzzy sets with logical operations, this method enables visualization of ambiguous and inaccurate data and provides a versatile and user-friendly strategy for decision analysis and problem solving.To assess seismic risk levels across the province, this study considered key earthquake vulnerability indicators: slope, elevation, proximity and density of fault lines, earthquake depth and magnitude, distance from epicenters, and density of seismic points. By integrating these factors, we were able to create a robust assessment that identified areas with varying degrees of earthquake vulnerability.

Our analysis revealed that a significant portion (around 22%) of Hormozgan province, encompassing 15,807.64 square kilometers, faces very high earthquake risk. Additionally, 8,133.15 square kilometers (11.50%) were identified as areas with very low seismic risk. By combining fuzzy logic models and hierarchical analysis, this study effectively identified specific zones within the province that require targeted earthquake preparedness and mitigation measures. These findings demonstrated the nuanced distribution of seismic risk levels across Hormozgan province, highlighting the need for tailored interventions to improve disaster resilience.This research highlights the importance of proactive earthquake risk assessment and zoning. By identifying areas with varying levels of seismic risk, this approach provides a crucial foundation for strategic decision-making. This allows for targeted risk management strategies and informed urban development planning in earthquake-prone regions like Hormozgan province, ultimately safeguarding communities and infrastructure from the potential impacts of seismic events.

Ultimately, the primary objective of this study is to evaluate and zone earthquake hazard levels in Hormozgan province using a hybrid Fuzzy AHP model. The application of Fuzzy AHP facilitates the analysis of various spatial parameters based on theirimportance weights to generate a vulnerability map. This approach proved instrumental in effectively assessing and zoning the vulnerability of Hormozgan province to seismic hazards.By leveraging integrated methodologies, we were able to comprehensively assess seismic risk and identify areas requiring targeted interventions. These insights provide valuable resources for policymakers, urban planners, and disastermanagementstakeholders, which emphasize the importance of informed decision-making to bolster earthquake resilience in vulnerable regions.Moving forward, this research lays the foundation for informed strategies to enhance disaster preparedness and mitigate the impact of seismic events in Hormozgan province and similar earthquake-prone areas.