Spatial-Temporal Characteristics of Hourly Extreme Precipitation in the Hengduan Mountain during 2001 -2020
摘要
Extensive research has been conducted on daily scale precipitation the Hengduan Mountain.The hourly scale data, which provides additional insights such as diurnal patterns, remains largely unexplored.Therefore, a fundamental study of the characteristics of extreme precipitation at the hourly scale is essential in the Hengduan Mountain.In this study, we analyzed the spatial and temporal distribution characteristics of hourly extreme precipitation (95th percentile, R95) and very extreme precipitation (99th percentile, R99) using Multi-Satellite Retrievals for Global Precipitation Measurement (IMERG) half-hourly satellite precipitation data from 2001 to 2020.Furthermore, we explored further the contribution to the whole year of rainy and non-rainy seasons periods.The results showed that the distribution pattern of hourly extreme precipitation and hourly very extreme precipitation thresholds, amount, intensity, and duration were decreasing from southeast to northwest in the Hengduan Mountain, and the number was high in the east and west but less in the center.Hourly extreme precipitation and hourly very extreme precipitation amounts occupied 29.58% and 10.15% of the annual total amount, respectively.In the analysis of interannual variability, an increasing trend in the amount, number and intensity were found for hourly extreme precipitation and hourly very extreme precipitation, while the duration is generally showed a decreasing trend, with an increase in the amount of 4.93 and 2.83 mm annually, respectively.The amount experienced a significant increase in the northeastern part of the Hengduan Mountain.In terms of diurnal variations, the hourly extreme precipitation and hourly very extreme precipitation amount and number were concentrated at nighttime, with two peaks during 17:00 (Beijing Time, same as after) -21:00 and 00:00 -02:00.A discrepancy in the distribution of the maximum occurrence time were found in the northern and southern regions in the Hengduan Mountain.