Weather Hazards Dynamically Reshape Navigability in China's Inland Waterways

As global temperatures rise, the spatial and temporal patterns of weather hazards are shifting, increasingly affecting industries vital to economic growth. Shipping, the backbone of global trade, is particularly susceptible, yet inland waterways—crucial for linking domestic regions to international markets—have received insufficient attention. This study presents the first quantitative assessment of how weather hazards impact inland waterway operations, focusing on China’s Yangtze River and Grand Canal system, the world’s busiest inland waterways. Between 2000 and 2024, these waterways averaged 301 suitable navigation days per year, marking an overall improvement over the preceding two decades, largely attributed to a 55% decline in strong wind events, from ~31 to ~14 days annually. However, low visibility remains the dominant constraint on navigability, causing ~44 days of disruption annually, with fog and haze emerging as the primary contributors. Heavy rainfall, intensifying with warming, leads to ~10 days of disruption, ranking as the third major hazard to navigation. Simulations suggest that improving navigation technologies, such as lowering visibility requirements from 2,000 meters to 1000 or 500 meters, could extend navigability on the Lower Yangtze River by 25 to 35 days annually, enhancing operational efficiency and fostering economic growth.