Prediction of long-term future runoff under multi-source data assessment in a typical basin of the Yangtze River

Study region: Three Typical Basins of the Yangtze River (YRB), China Study focus: Meteorological factors, such as precipitation, are key drivers of the hydrological system and critical inputs in hydrological modeling, and accurate meteorological data are essential to simulate hydrological processes. This study compares and evaluates the CN05.1, CMFD, and ERA5-L and meteorological forcing datasets in three typical basins of the Yangtze River and predicts the future runoff changes in the basin based on CMIP6 data. New hydrological insights for the region: This study indicated that (1) the CN05.1 data exhibit the best applicability on the interannual and intra-annual scales in YRB, while ERA5-Land performs better in the upper reaches, and CMFD is more suitable for the middle and lower reaches. (2) Future runoff is projected to initially decrease and then increase, with the inflection and inflections points of runoff occurring earlier in the ssp585 scenario compared to the ssp245. The risk of spring flooding is increasing in CS and JZ river basin, and the risk of flooding is decreasing in the FH River Basin as the flood peaks are earlier. (3) Significant trend changes are anticipated in the future, with climate change contributing over 90 % of the runoff changes in the CS, while human factors will increasingly influence the JZ and FH basins.