Characteristics of Summer Hourly Extreme Precipitation Events and Its Local Environmental Influencing Factors in Beijing under Urbanization Background

Studies on urban extreme precipitation and its influencing factors are significant for prevention reduction of meteorological disasters; however, few studies focus hourly (HEP) events due to the limitation observation. By using summer data in Beijing from 1980 2020, spatial distribution temporal variation HEP as well local environmental investigated. It is found that both amount frequency affected by topography, with high values windward slope area. The 160–200 mm, accounting 42–47% annual amount, while proportion only 5.5–6.0%. Although decrease past 41 years, those present an opposite trend mainly increasing since 2003 this a phenomenon worthy attention. A similar bimodal pattern diurnal HEP, two peaks 19–22 LT 01–05 LT, respectively, indicating HEPs more concentrated evening early morning especially Moreover, urbanization process consistent change implying stronger heat island intensity (UHI), higher probability HEP. Furthermore, convergence lines terrain also conducive heavy rainfall, lower tropospheric stability (LTS) convective available potential energy (CAPE) aerosols may affect Beijing.