Integrated assessment of direct and indirect economic impacts of urban pluvial flooding in metropolitan areas of South Korea

Urban flooding poses localized physical risks and cascading economic disruptions through interconnected regional systems. While flood modeling and structural flood-control measures have been extensively studied, limited attention has been paid to quantifying urban pluvial flood damage in relation to interregional economic linkages. This study addresses this gap by integrating high-resolution spatial flood-damage data with an interregional input-output model to assess direct and indirect economic impacts across six metropolitan cities in South Korea. Results reveal substantial spatial heterogeneity in direct damage, shaped by urban morphology, topography, and spatial distribution of exposed assets. Seoul showed severe residential damage, Incheon exhibited industrial losses in exposed urban districts, and Daejeon displayed a clear distinction between residential and industrial impact zones. Under the adopted static interregional input-output framework, estimated indirect economic losses exceeded direct physical damages across six cities, particularly through internal propagation within regional production networks. This result should be interpreted as evidence of potential short-run economic amplification under fixed interindustry relationships, rather than as long-term post-disaster losses. Sectoral analysis under the Seoul flood scenario identified raw material manufacturing, energy, and scientific services as susceptible to upstream disruptions. These findings indicate that urban flood-risk management should consider not only site-specific exposure but also the economic structures through which localized physical damage can propagate within and across regions. The proposed framework supports differentiated resilience planning by distinguishing between cities requiring local absorptive capacity and those requiring interregional supply-chain coordination.