Response of precipitation to extensive urbanization over the Pearl River Delta metropolitan region

Spatiotemporal changes in characteristics of rainfall events with different duration occurring in the rainy season in Guangzhou, a typical city in South China with high urbanization, were detected using the observed hourly precipitation data. Rainfall changes were further related to urbanization showing in high-resolution land use/land cover data. Results showed that Guangzhou had experienced accelerated urbanization with the fraction of urban land cover increasing from 2.9% in the 1980s to 14.9% in the 2000s. In the context of rapid urbanization, the precipitation amount over the urban center and downwind area were also higher than that over the upwind area during 1984–2016. Rainfall events with a short duration (≤ 6 h) over the urban center and downwind area were more intensive than those over the upwind area. The intensive rainstorms with a short duration tended to occurred more frequently in the afternoon than the early morning. The unimodal rainfall events with a frontal peak were more likely to occur more over the urban center than the upwind area, while the bimodal rainfall events with two peaks in the early and the middle occurred more frequently over the downwind than the urban center and the upwind area.