High-speed rail, land-use transformation, and natural capital depletion: A comparative analysis of China and Japan

High-speed rail (HSR) expansion plays a crucial role in economic growth and regional connectivity but also presents significant environmental challenges, particularly through natural capital depletion. This study examines how HSR expansion influences land-use changes and natural capital loss in China and Japan, considering both station-level impacts and broader market access (MA) effects. Using a combination of Difference-in-Differences (DID) and MA-based analyses, we find that in China, natural capital loss is primarily driven by reductions in agricultural and forested land, whereas in Japan, it stems largely from the expansion of built-up areas in peripheral cities and agricultural land conversion. The estimated economic loss from natural capital depletion amounts to 3.12 billion USD in China and 2.53 billion USD in Japan, highlighting the substantial environmental costs of HSR expansion. We further validate the mechanisms of these impacts through observed population growth and patterns of industrial specialization. These findings underscore the need for policy measures that balance economic benefits with environmental sustainability, advocating for integrated land-use planning and natural capital conservation to mitigate long-term environmental impacts.