Spatiotemporal variation characteristics of precipitation and urbanization effects in Shenzhen from 1960 to 2019

To explore the evolution of precipitation in megacities under changing environments and human activities, Shenzhen was chosen as the study area. Using daily precipitation data from 10 stations (1960–2019), the TFPW-MK and EOF methods analyzed the spatiotemporal characteristics of precipitation. The findings are: (a) Precipitation in Shenzhen shows a slight upward trend with spatial variations. Western stations exhibit a downward trend. The oscillation period of precipitation indicators is about 10–20 years, with an abrupt change in 1991. (b) Different precipitation indicators have similar distribution patterns. The first mode shows global consistency, indicating overall high or low precipitation, and a shift in the precipitation center from northwest (before 1990) to southeast (after 1990). The second mode shows an “East-West” reverse distribution. (c) Urbanization significantly affects precipitation distribution and has an enhancing effect on precipitation. The smaller the time scale, the stronger the effect of urbanization on extreme precipitation.