Characterizing Short-Duration Rainfall Events on the Tibetan Plateau Based on Ground Observation, Satellite Remote Sensing, and Reanalysis Data

Given the vast expanses of bare soil and sparse grassland in the Central and Western Tibetan Plateau (CWTP), the duration of precipitation serves as a critical control on key hydrological and geomorphological responses, such as runoff generation, soil erosion, and sediment transport. This study analyzes the spatial distribution of precipitation events with different durations (short-duration, medium-duration, and long-duration) across the Tibetan Plateau (TP). To explore the differences in precipitation duration between the central-western and eastern TP, we utilize hourly precipitation data from a newly established cross-sectional rainfall observation network (53 gauges) on the CWTP and the China Meteorological Administration (CMA) observation (145 gauges) on the eastern TP for comparison. The main conclusions are as follows: (1) Short-duration (1-3 hours) precipitation events contribute more than 50% of the total rainfall in the CWTP. In contrast, short-duration events contribute less than 30% in the eastern TP, where medium- and long-duration precipitation events dominate. (2) The reanalysis data ERA5 and the high-resolution atmospheric simulation data HAR2 tend to systematically underestimate (overestimate) the contribution of short-duration (long-duration) precipitation events. Specifically, they exhibit mean biases of 23% and 19% for short-duration precipitation, and 34% and 20% for long-duration precipitation, respectively. (3) The satellite remote sensing precipitation data IMERG perform well in estimating the contribution of precipitation events, with biases mostly within 30%. By comparing the original and gauge-calibrated satellite datasets, the results show that calibration with coarse temporal resolutions (daily or monthly) does not necessarily improve the identification of short-duration precipitation events. Our results not only enhance the understanding of precipitation characteristics and processes over the Tibetan Plateau, but also provide valuable guidance for hydrological modeling and the evaluation and improvement of satellite-based precipitation data.