Abstract：We use the data from 51 GNSS stations, 116 meteorological stations, 2 radiosonde (RS) stations and ERA5 in Henan province spanning from UTC July 15 to 25, 2021. By combining GNSS derived atmospheric PWV with multiple meteorological elements, we analyze the spatial and temporal variation characteristics and internal relationship of precipitation, PWV, relative humidity and total cloud cover during the “21·7” heavy rainfalls in Henan province. The results show that the correlation coefficient between GNSS-PWV and RS-PWV is more than 0.95, the absolute bias is less than 0.7 mm, and RMS is less than 2.9 mm. The absolute bias of GNSS-PWV and ERA5-PWV are less than 3 mm, and the RMS range is 2.5 to 4 mm. During the period of extremely heavy rainfalls, PWV firstly increased with the increase of precipitation and then decreased with the decrease of precipitation. At 4 to 6 h before the peak of the precipitation, PWV began to increase sharply to the extreme value, ΔPWV with a range of 7.35 to 9.02 mm. When the precipitation reached the extreme value, the PWV content over the GNSS stations also reached the peak value (above 70.58 mm). The spatial distribution of PWV, relative humidity, total cloud cover and precipitation are consistent with each other. The PWV content over central, northern and western regions with rainfalls in the province was constantly at a high level (above 65 mm), while the PWV content over the eastern region without rainfalls was lower (below 65 mm).
ZHENG Zhiqing,ZHANG Kefei,SHI Jiaqi et al. Using GNSS-PWV Combined with Multiple Meteorological Elements to Analyze the Process of “21·7” Severe Rainstorm in Henan Province[J]. jgg, 2023, 43(8): 809-815.
