**5. Conclusions**

We analyzed the correlations between land-use composition, the percentage coverage of three major land use types (%U, %V, and %W), and LST for different window sizes or urban land management units. The land use maps showed that inner Hanoi experienced substantial changes in land-use in a one-year interval from years 2016 to 2017, likely influenced by the City's Master Plan 2030. High correlations were observed between the percentage coverage of each land-use type (i.e., %U, %V, and %W) and LST. They are coherent with the findings of the previous studies, while considering different window sizes on the hottest day of 2017 (4 June). The vegetation and water coverages, acting as cooling effect, exhibited negative correlations with LST. In contrast, the urban coverage was proportionate to the LST. Consequently, a multivariate regression model was derived by taking into account the correlations between land-use composition and LST. We successfully validated our model for the prediction of LST on another hot day (1 June 2016). The validated model in this research provides an opportunity for urban planners and designers to suggest measures for adjusting the LST and the associated effects of SUHI by managing the land use composition and percentage coverage of the individual land-use types (%U, %V, and %W). This model demonstrates that a substantial decrease in LST can be achieved by increasing the proportion of vegetation and water for improved comfortable and sustainable living in the city. Despite this, we have provided some interesting findings, and we did not deeply analyze the traditionally-defined SUHI. In addition, impacts of currently rapid urbanization on SUHI and its consequence in suburban area of inner Hanoi can be further investigated.

**Author Contributions:** N.T.H. conceived the project, conducted research, performed initial analyses, and wrote the first manuscript draft. R.C.S. and D.D.C. provided helpful discussions during the conception of the project. D.-P.T. assisted in processing and analyses of data. K.-A.N. and Y.-A.L. enhanced the data processing, analysis, discussion, and conclusion. K.-A.N. and C.-L.L. improved the result presentation. Y.-A.L. rewrote around 70–80% of the first manuscript and finalized it for the first communication with the journal. Y.-A.L. and K.-A.N. implemented major revision to meet the standard of three anonymous reviewers.

**Funding:** Nguyen Thanh Hoan was funded by the Vietnam Academy of Science and Technology (VAST) under project code: VAST01.05/16-17, and Vietnam National Foundation for Science and Technology Development (NAFOSTED) under grant number 105.08-2015.31. K.A Nguyen and Y.A. Liou appreciate the financial support of Taiwan's Ministry of Science and Technology under project codes 105-2221-E-008-056-MY3, 107-2111-M-008-036 and 107-2622-E-008-006-CC3.

**Acknowledgments:** This research was assisted in collecting and processing of data from colleagues in Institute of Geography, VAST including: Ho Le Thu, Nguyen Van Dung and Hoa Thuy Quynh.

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