Assessment of Flood Risk Hotspots in Port Areas: A Multi-Hazard Approach for Antalya Port

Seaports are vital nodes in the global supply chain, facilitating approximately 80% of world trade However, their strategic location in low-lying coastal zones renders them inherently vulnerable to climate change-induced hazards, particularly river and coastal floods (UNCTAD, 2011; UNCTAD, 2017; IPCC, 2021). While global-scale assessments have highlighted the aggregate risk to critical transportation infrastructure like seaports (Verschuur et al., 2023), there is a scarcity of site-specific, quantitative damage assessments that consider local land-use characteristics and multi-hazard interactions (Bolangi Yavuz et al., 2022). Traditional port management often prioritizes protection against catastrophic, low-frequency events (e.g., 100 or 500-year return periods). However, recent evidence suggests that high-frequency events may impose a cumulative economic burden that exceeds expectations (Ward et al., 2011). This study addresses this gap by presenting a high-resolution economic damage assessment for the Antalya Port region, a representative Mediterranean hub exposed to both fluvial and coastal inundation risks. The primary objective of this research is to quantify the potential direct economic damage caused by river and coastal floods. Specifically, the study aims to: (1) estimate the monetary damage from river floods across a range of return periods and coastal inundation driven by sea-level rise projections; (2) compare the economic impact of frequent flooding versus rare catastrophic events; and (3) identify spatially distinct "hotspots" of economic vulnerability within the port’s industrial and commercial zones to guide targeted resilience planning. To achieve these objectives, a quantitative, land-use-based risk assessment methodology was employed. The study integrated the European Commission’s Joint Research Centre (JRC) global flood hazard maps (derived from the LISFLOOD model) and elevation data (CLMS, 2016) with high-resolution local land-use plans (1:5,000 scale). River flood scenarios were analysed for nine return periods ranging from frequent (10-year) to extreme (500-year) events. Additionally, coastal flood scenarios incorporating sea-level rise projections were evaluated. Direct economic damage was estimated using established depth-damage functions tailored to the specific asset classes present in the port region (Huizinga et al., 2017), with costs adjusted to current values using local economic indices (TUIK, 2025). Finally, a Getis-Ord Gi* spatial statistic was applied to identify statistically significant clusters (hotspots) of high damage (Getis while potential losses increase by roughly 37% between the 10-year and 100-year events, the marginal increase from the 100-year to the 500-year event is only 4.5%. This suggests that the majority of valuable assets are situated in low-lying areas susceptible to frequent inundation. Furthermore, spatially, the damage is not evenly distributed. Over 96% of the total direct economic loss is concentrated in the industrial (free zone, storage) and commercial areas in the port, rather than the operational quay infrastructure. The hotspot analysis confirmed that the economic epicentre of the risk is persistently clustered in the northern industrial zones across all flood scenarios. This study challenges the conventional paradigm of port risk management which often focuses on resisting extreme, low-probability disasters. The findings demonstrate that for the Antalya Port, and potentially similar Mediterranean ports, the dominant economic threat arises from chronic, high-frequency floods. Consequently, adaptation strategies should shift from designing solely for rare catastrophes to managing cumulative losses from frequent events. The identification of persistent hotspots in the industrial hinterland provides a concrete evidence base for decision-makers to prioritize spatial adaptation measures, such as localized flood defences or zoning adjustments, ensuring more cost-effective resilience planning.