TPRD3km: An observation-constrained high-resolution runoff data for Third Pole transboundary rivers

Quantifying river runoff is essential for water resource planning, flood control, and ecological protection globally. However, in the high-mountain Third Pole (TP) region, with extensive cryosphere coverage and harsh climate, runoff observations are extremely scarce, especially for transboundary rivers. Complex runoff processes, strongly influenced by snow and glacier melt, challenge hydrological modeling. Currently, long-term, high-resolution runoff datasets are still lacking in TP. Here, we employ an observation-constrained physically based cryosphere-hydrological model to simulate daily runoff during 1981‒2020 over seven transboundary TP rivers. This model is calibrated and validated with daily runoff observations near seven basin outlets, as well as available daily observations from sub-basins and hourly observations. Results show that the model can effectively reproduce the daily streamflow dynamics during both calibration and validation periods in seven TP basins, with Kling-Gupta-Efficiency, Nash-Sutcliffe-Efficiency and correlation coefficients all exceeding 0.67, 0.63 and 0.82, respectively, and absolute-percentage bias within 15.2%. Additionally, validations at sub-basins and hourly-scale validations yield satisfactory results. Furthermore, the snow and glacier modules are validated using reliable remote-sensing-derived data, showing good consistency. Consequently, we generate a long-term 3-km, daily gridded runoff dataset and streamflow records for 11 TP cross-sections, which provide essential support for regional sustainable development and ecological conservation.