The role of climate and urbanization in compound meteorological event exposure in China’s megacities

Compound precipitation and wind speed extremes (CPWE) pose significant threats to the sustainable development of urban areas. This study investigated the spatial evolution characteristics, potential population exposure risk, and multidimensional inequality of CPWE within nine urban agglomerations in China, each containing at least one city with a GDP exceeding one trillion yuan, utilizing spatiotemporal statistics and attribution analysis. The results indicated that the intensity of CPWE in these urban agglomerations decreased from southeast to northwest, and the population exposed to mild, moderate, severe, and extreme levels accounted for 58 %, 28.3 %, 11.4 %, and 2.3 % of the total, respectively. Changes in exposure risk were driven by climate effect (58.29 % ± 12.77 %), followed by population (32.15 % ± 6.20 %) and interaction effect (9.55 % ± 5.14 %). Pearl River Delta (PRD) and Yangtze River Delta (YRD), identified as particularly vulnerable, experienced an increase in CPWE intensity exceeding 0.015 /10a. An increase of approximately 0.62 × 104 people per decade was observed for exposure risk, with over 20 % of the population facing severe or extreme levels, mainly due to the climate effect. CPWE exposure risk was significantly unequal across various dimensions (spatial autocorrelation: Moran’s I = 0.3798, P = 0.001; Gini coefficient: 0.08–0.5). Areas characterized by high-risk and balanced development (e.g., PRD, YRD) exhibited lower inequality, whereas regions featuring low-risk and concentrated development (e.g., GPZ) demonstrated higher inequality. The climate effect was the predominant influence in the low-risk areas as well as most high-risk areas. These findings support the targeted implementation of appropriate climate adaptation policies to promote regional sustainable development.