Multiple Drivers of Urban Road Subsidence: Policy Implications from Cases Reported in Chuncheon, South Korea

A clear increasing trend has been observed in land subsidence incidents reported in non-limestone soils worldwide, suggesting that urbanization may have contributed to surface degradation, regardless of soil type. To identify features of modern urban structures that threaten urban safety, this study employed a two-track research strategy combining a literature review with case studies. The review of 125 published articles revealed a substantial increase in related research, reflecting growing concern over the severity and potential impacts of land subsidence in urban areas. It also identified a shift in research focus from case-specific investigations of immediate causes toward the examination of long-term anthropogenic drivers. Accordingly, land subsidence has increasingly been viewed not merely as an unexpected natural hazard, but as a foreseeable urban hazard potentially intensified by climate change. Major contributing factors include increasing structural loads associated with urban development, the formation and expansion of subsurface voids, reduced groundwater recharge due to extensive impervious surfaces, and differential expansion and contraction between subsurface layers and asphalt surfaces, which may be exacerbated by urban heat island effects. Analysis of 11 land subsidence incidents in Chuncheon City, South Korea further supported this shift in perspective. Half of the incidents were associated with pipe leakage, while the remainder involved asphalt surfaces subsiding into subsurface voids under extreme weather conditions. Two policy implications are proposed: expanding large-tree planting to enhance canopy effects and mitigate extreme weather impacts and promoting sustainable alternatives to asphalt pavement that can restore groundwater recharge and better synchronize surface–subsurface movement.