**6. Conclusions**

Climate selection is an important factor influencing hydrological processes. In this study, a physical-based baseflow separation filter was used to separate baseflow from total streamflow to assess baseflow responses to climate (e.g., varying temperature and rainfall). Three representative general climate models with two climate scenarios were used to predict baseflow and analyze trends and driving forces in the Weihe River Basin. Our analyses proved that the GCMs could capture the streamflow variations under future climate conditions and could be used to investigate baseflow characteristics at the basin scale. Our findings showed that the selection of climate had an approximate impact on the baseflow projection. The baseflow derived from three climate models (i.e., the future climate conditions) with two representative scenarios demonstrated a decreasing baseflow trend in this basin, reaching a strong decreasing trend approximately in 2040. For the historical periods, the baseflow had two intersects using the MK test, showing that the response of baseflow was much more sensitive than that of streamflow. Streamflow flow lagged about 20 years behind baseflow. Annual baseflow anomalies are an efficient tool that can be used to evaluate drought events under future climate conditions. Our study predicted baseflow droughts (~10 years) in this catchment starting in 2041. Although it is challenging to forecast water-storage variations accurately (e.g., drought events), the baseflow projection from climatic scenarios in GCMs is a promising way to assess baseflow responses to future climatic changes.

**Author Contributions:** Conceptualization, J.Z. and P.Z.; methodology, P.Z., Y.Z., L.C., G.F. and G.Z.; software, P.Z.; validation, J.Z.; formal analysis, J.Z. and P.Z.; investigation, S.L.; resources, C.H. and M.M.; data curation, M.M.; writing—original draft preparation, J.Z. and P.Z.; writing—review and editing, J.Z., P.Z., Y.Z., L.C., G.F., Y.W., Q.L., S.L., S.Q., C.H. and G.Z.; visualization, J.Z.; supervision, J.S.; project administration, J.Z. and P.Z.; funding acquisition, P.Z. and G.Z. All authors have read and agreed to the published version of the manuscript.

**Funding:** This work was supported by the National Natural Science Foundation of China (42001034, 42101038, 41701022, 51679200 and 42207100), the Key Research and Development Program of Shaanxi (2019ZDLSF05-02), the Project for Outstanding Youth Innovation Team in the Universities of Shandong Province (2019KJH011), the Natural Science Foundation of the Shandong Province (ZR2019BD059), Postdoctoral Funding of China (2018M642692), the Second Tibetan Plateau Scientific Expedition and Research Program (STEP) (2019QZKK0903), and Key Science and Technology Program of Henan Province, China (222102320083).

**Data Availability Statement:** Data can be obtained upon request from the corresponding author.

**Acknowledgments:** We thank three anonymous reviewers and the editors for their thoughtful comments and suggestions. The authors would like to express their gratitude to EditSprings (https://www.editsprings.cn/, accessed on 3 September 2019) for the expert linguistic services provided.

**Conflicts of Interest:** The authors declare no conflict of interest.
