午夜欧美大片免费观看,欧美激情综合五月色丁香,亚洲日本在线视频观看,午夜精品福利在线

Using the hourly precipitation data from 40 national stations in Hebei Province from 2005 to 2019, the spatial and temporal distribution characteristics of hourly precipitation and heavy hourly precipitation in Hebei Province are analyzed. The results show that: (1) The frequency of hourly precipitation decreased in recent years, while heavy hourly precipitation had no apparent change trend. The monthly changes in hourly precipitation, precipitation frequency, precipitation intensity, and hourly heavy precipitation frequency showed a singlepeak distribution. The hourly heavy precipitation frequency showed a trend of annual differentiation. The differentiation became greater, making the extreme occurrence of hourly heavy precipitation events more prominent. (2) The annual precipitation generally showed a trend of high in the east and low in the west, and high in the south and low in the north. The large value centres were mainly located in the northeast and southwest regions. The frequency and intensity of precipitation were significantly affected by the terrain. The two large value centres of precipitation frequency were located in the northern and centralwestern regions with higher altitude, and that in the plains was lower. However, the area with large precipitation intensity was located in the northeast, caused by the combined influence of the subtropical high and topography. (3) Precipitation in Hebei was mainly concentrated in the evening to night, and the time of peak precipitation appeared to be eastward delayed. Due to the influence of local convective weather in the afternoon, the maximum peak occurred mainly around 17:00 (Beijing time). Hourly heavy precipitation occurred more frequently. (4) The high incidence of heavy hourly precipitation was from July to August, mainly concentrated in the east and south of Hebei. Its maximum value occurred in the northeast and Shijiazhuang. (5) The precipitation in the south was mainly due to the contribution of precipitation intensity. The precipitation in the northern, western mountainous areas and the northwestern Bashang area was more affected by the precipitation frequency; the precipitation in the northeast was caused by the combined effect of precipitation frequency and precipitation intensity.