关键词: 梵净山, 海拔高度, 山地降水, 日变化

Abstract:

To deepen the understanding of precipitation patterns in complex mountainous terrain, hourly precipitation data from three meteorological observation stations at different altitudes on the eastern side of the Fanjing Mountain in Guizhou Province in the flood season from May to October during 2022-2023 were used to analyze the diurnal variation characteristics of precipitation at the foot, mid-slope and summit stations. The results show that the amount and intensity of precipitation from night to morning increase with increasing altitude, while both decrease with increasing altitude from afternoon to evening. The periods with the large precipitation amount at stations on the foot and middle of the mountain occur from the late afternoon to evening, while at the summit station it concentrates from the early morning to morning. The precipitation at three stations mainly originates from rainfall events lasting from 2 to 18 hours. At the summit station, the precipitation amount during rainfall events lasting less than 8 hours is greater at night than during the day, while at the foot and mid-mountain stations, this characteristic is only observed in rainfall events lasting less than 3 hours.The peak period of precipitation shows a systematic delay with altitude increasing. From the night to the morning at the station at the foot of the mountain, then from the night to the noon at the station on the middle of the mountain, and finally transitioning from the noon to the early morning at the top station of the mountain, it exhibits a trend of “spreading from the morning to the noon and then to the early morning”. Short duration heavy precipitation (with precipitation amount greater than or equal to 25 mm) mostly occurs in the morning and has the highest frequency, while long duration precipitation has the highest proportion of precipitation amount.

Key words: the Fanjing Mountain, altitudes, mountain precipitation, diurnal variation