An integration of gauge, satellite, and reanalysis precipitation datasets for the largest river basin of the Tibetan Plateau

Abstract

Abstract. As the largest river basin of the Tibetan Plateau, the upper Brahmaputra River basin (also called “Yarlung Zangbo” in Chinese) has profound impacts on the water security of local and downstream inhabitants. Precipitation in the basin is mainly controlled by the Indian summer monsoon and westerly and is the key to understanding the water resources available in the basin; however, due to sparse observational data constrained by a harsh environment and complex topography, there remains a lack of reliable information on basin-wide precipitation (there are only nine national meteorological stations with continuous observations). To improve the accuracy of basin-wide precipitation data, we integrate various gauge, satellite, and reanalysis precipitation datasets, including GLDAS, ITP-Forcing, MERRA2, TRMM, and CMA datasets, to develop a new precipitation product for the 1981–2016 period over the upper Brahmaputra River basin, at 3 h and 5 km resolution. The new product has been rigorously validated at different temporal scales (e.g., extreme events, daily to monthly variability, and long-term trends) and spatial scales (point and basin scale) with gauge precipitation observations, showing much improved accuracies compared to previous products. An improved hydrological simulation has been achieved (low relative bias: −5.94 %; highest Nash–Sutcliffe coefficient of efficiency (NSE): 0.643) with the new precipitation inputs, showing reliability and potential for multidisciplinary studies. This new precipitation product is openly accessible at https://doi.org/10.5281/zenodo.3711155 (Wang et al., 2020) and additionally at the National Tibetan Plateau Data Center (https://data.tpdc.ac.cn, last access: 10 July 2020, login required).

Vanishing Glaciers at Southeast Tibetan Plateau Have Not Offset the Declining Runoff at Yarlung Zangbo

“…As the largest (240,000 km 2 ) river basin of the TP, the upper Brahmaputra basin (UBB; also called “Yarlung Zangbo”) has profound impacts on the water security of local and downstream inhabitants (Wang et al., 2020; Yi et al., 2020). The UBB also holds most of the glaciers in the eastern‐Himalaya and Nyainqêntanglha mountains with the strongest mass loss occurring in the monsoon‐affected south‐eastern TP (Yang et al., 2016; Figure 1).…”

“…Input precipitation data are updated from Wang et al. (2020) with high spatiotemporal resolution. The calibration and validation steps are completed at Nuxia station and Dexing site of the latest accessible Chinese county Motuo.…”

“…The meteorological forcing data except precipitation were provided by the National Tibetan Plateau Data Center (https://doi.org/10.11888/AtmosphericPhysics.tpe.249369.file). The high spatiotemporal resolution (5 km, 3 h) precipitation data set was compiled byWang et al (2020) from the following location: https://doi.org/10.5281/zenodo.3711155. The other data used in this study were obtained from the following…”

A high-accuracy rainfall dataset by merging multiple satellites and dense gauges over the southern Tibetan Plateau for 2014–2019 warm seasons

“…These gauges provide measurements of precipitation in the liquid phase (i.e., rainfall) at the event timescale. A couple of recent studies have demonstrated the utility of this rain gauge network (Xu et al, 2017;He et al, 2017;Tian et al, 2018;Wang et al, 2020). For instance, Xu et al (2017) evaluated the performance of TRMM and GPM and the dependence on topography and rainfall intensity based on the network.…”

“…Their results demonstrated that the data quality of this dense gauge network is strictly controlled, serving as the currently highest gauge density for satellite product evaluation on the TP. Wang et al (2020) used the gauge data to validate their reproduced precipitation dataset. However, there is not a merging product that assimilates the observations from this dense rain gauge network.…”