**5. Conclusions**

First of all, we show the good performances of the nonlinear regression model (Equation (2)) for estimating Sentinel-2 LAI based on the strong exponential relationship between NDVI and LAI and the PML-V2.1 model of estimating ET and GPP at 10m resolution using Sentinel-2 LAI and land cover map. This Sentinel-2-based technology using the

PML-V2.1 model with surface meteorological forcing data as the input for estimating ET provides a new framework to evaluate city-level hydrological dynamics in urban ecosystems. Secondly, we find that plant transpiration from greenbelts with trees and grassland play an important role in most impervious areas for Beijing Sponge City. Thirdly, mixed forests, forest parks and croplands due to their high ET have much smaller surface heat contribution than the impervious and grasslands, providing better ecosystem services (e.g., cooling) for the sponge city.

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

**Funding:** This research was funded by the Beijing Municipal Natural Science Foundation (grant number 8212017), the National Natural Science Foundation of China (grant number 42001019) and the Shanghai Sailing Program (grant number 19YF1413100). The APC was funded by the Beijing Municipal Natural Science Foundation (grant number 8212017).

**Data Availability Statement:** The resulting dataset in this study is available at https://doi.org/10.6 084/m9.figshare.14387630.v2 (accessed on 8 April 2021). More data and codes can be accessible from the corresponding author upon request.

**Acknowledgments:** We acknowledge the Beijing Water Science and Technology Institute (BWSTI) for providing technical and financial supports to this work. We thank the three anonymous reviewers and editors for their constructive suggestions and comments.

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