Widening Urban–Rural Precipitation Differences in China: Regionally Varied Intensification Since 2000

Abstract

Urbanization tends to modify heavy precipitation patterns, resulting in increased risk of extreme hazards. However, how urbanization differentially modulates various precipitation categories—captured by indices based on all precipitation events and those representing extremes—has received limited attention. Key uncertainties remain regarding the direction of response (intensification or moderation) and potential thresholds for urbanization-induced precipitation shifts. We assessed the urbanization effects on precipitation across 37 urbanized regions in China from 1980 to 2022, and found the urbanization effects have intensified in most cities since 2000. Urbanization generally reduced the number of wet days but increased the frequency of extreme precipitation. Moreover, urbanization induced an increase in total precipitation, the simple precipitation intensity index, and interannual variability nationally, with precipitation primarily being altered in the cold climate zone and in medium-sized cities. Anthropogenic drivers (e.g., urban area trend) and climatic drivers (e.g., relative humidity) predominantly govern the spatial variability in urbanization effects on all precipitation events, while climatic drivers (e.g., convective available potential energy) primarily modulate the spatial variability of urbanization effects on extreme precipitation. Notably, the urbanization effect on precipitation has intensified in recent decades (2000–2022), with more pronounced effects in arid climate zones and megacities. Anthropogenic and climatic factors both exacerbate the urbanization effect. Our findings provide valuable scientific knowledge for policymakers in urban planning and hazard warning.