Abstract
<title>Abstract</title> <p>Climate change is altering rainfall patterns and increasing the frequency of extreme rainfall events, thereby placing greater pressure on urban drainage systems and increasing flood risk. To improve urban stormwater management, China has actively promoted sponge city development, in which wetlands serve as important natural infrastructure for regulating urban runoff. However, understanding of how wetland landscape patterns influence the spatial variability of urban runoff remains limited. Therefore, this study examined three Chinese cities characterized by relatively low annual precipitation but frequent extreme rainfall events. Urban runoff was simulated using InfoWorks ICM under a unified rainfall scenario, and intercity differences in wetland landscape patterns were assessed. Ordinary least squares regression was then used to evaluate the contribution of wetland landscape characteristics to the spatial variability of runoff. The results revealed significant intercity differences in both runoff responses and wetland landscape patterns. After controlling for conventional urban environmental factors, wetland-related variables provided additional explanatory power for the spatial variability of urban runoff. Wetland cover, patch density, edge density, and connectivity were negatively associated with runoff, whereas landscape shape complexity was positively associated with runoff. These findings indicate that wetland landscape patterns explain additional variation in urban runoff beyond that accounted for by conventional urban environmental factors. Accordingly, urban stormwater management and spatial planning should consider not only wetland extent but also wetland landscape configuration, particularly spatial arrangement and connectivity, to strengthen flood resilience and climate adaptation in highly urbanized areas.</p>