-    Building the scientific basis and selecting an appropriate methodology to estimate water quality parameters (chlorophyll-a concentration (Chl-a), Secchi Disk Depth (SD), and the lake trophic state index (TSI)) from Landsat 7, 8, and Sentinel 2 images acquired in the 2005-2019 period ;
-    Modeling urbanization and climate change imprints through mapping the expansion of impervious surface and the change in land surface temperature (LST) of Hanoi city from satellite images during the 2005-2019 period;
-    Identifying the relationship between the lake TSI with LST, and the expansion of impervious surface during the 2005-2019 period.

Theoretical results: The study has built an in situ dataset of water parameters and trophic state of 10 lakes in Hanoi and developed 4 empirical models for estimating Chla, SD, and TSI from Landsat 8 and Sentinel 2A images. These models were successfully applied to assess the trophic state of 10 studied lakes (West Lake, Truc Bach, Giang Vo, Hoan Kiem, Bay Mau, Hai Ba Trung, Nghia Tan, Van Quan, Linh Dam, Yen So). Estimated results evidenced the change of the trophic state of lakes in Hanoi from the highly eutrophic level during 2005 - 2010 into the hypertrophic level since 2015. Over-urbanization has been observed in Hanoi through the strong expansion of built-up area (impervious surface) over 12 the city’s inner districts, from 24% total area in 2005 to 53% total area in 2019. This expansion was highly correlated to the expansion of high LST (R2 = 0.96) and mean LST of districts which are covered by >70 % built-up land (R2 = 0.78), demonstrating the double effect of urbanization and Climate Change on the city ecosystems. Under the impact of temperature raising as stated in RCP 4.5 and 8.5, Chl-a and accompanying TSI will be increased to 68 g/L and 1,4 TSI unit that requires efficient environmental monitoring and management.
Applied results: The model to estimate TSI directly from Landsat 8 level 2 data developed and validated in this project can be applied to monitor the trophic status of  lakes in Hanoi which can be used as a reference source to a proactive response to environmental problems related to the high trophic levels of lakes in the city.

This project first built an in situ dataset of water parameters and trophic state of 10 lakes in Hanoi and developed total 4 empirical models for estimating Chla, SD, and TSI from Landsat 8 and Sentinel 2A images.

- Scientific papers in referred journals (list):
1)    Pham Quang Vinh et al., 2021. Monitoring the trophic state of shallow urban lakes using Landsat 8/OLI data: a case study of lakes in Hanoi (Vietnam). Frontiers of Earth Science (Accepted). ISI list journal (https://www.springer.com/journal/11707). IF (2020) = 2.031; IF (5 years) = 1.836. Q2 in Earth and Planetary Sciences (https://www.scimagojr.com/ journalsearch.php?q=6200180160&tip=sid)
2)    Nguyễn Thiên Phương Thảo, Phạm Quang Vinh, Nguyễn Thị Thu Hà, Nguyễn Thùy Linh, 2021. Giám sát biến thiên mức độ phú dưỡng của hồ Hoàn Kiếm dựa vào hàm lượng chlorophyll-a tính toán từ ảnh Sentinel-2A. Tạp chí Khí tượng Thủy văn 2021, 721, 11–20; DOI:10.36335/VNJHM.2021(721).11–20. Available online at: http://tapchikttv.vn/article /1099
3)    Nguyễn Thùy Linh, Nguyễn Thị Hoa, Nguyễn Thị Thu Hà, Đặng Trung Tú, Phạm Quang Vinh, 2020. Đánh giá và giám sát hiện trạng phú dưỡng nước hồ Trúc Bạch theo không gian và thời gian sử dụng ảnh vệ tinh Sentinel 2A. Tạp chí Kinh tế môi trường. Số 9/2020, tập 6. Available online at: https://kinhtemoitruong.vn/danh-gia-va-giam-sat-hien-trang-phu-duong-nuoc-ho-truc-bach-50941.html
4)    Nguyen Thuy Linh, Pham Thi Huong Thao, Luong Thi Phuong, Vu Thi Han, Nguyen Thi Thu Ha, Pham Quang Vinh, 2019. Using Sentinel-2B Imagery to Estimate the Eutrophication Level of Linh Dam Lake, Hoang Mai District, Hanoi. VNU Journal of Science: Earth and Environmental Sciences, 35(4), 88-96. DOI: https://doi.org/ 10.25073/2588-1094/vnuees.4471
5)    Phạm Quang Vinh và nnk, 2020. Khảo sát sự biến thiên hàm lượng chlorophyll-a trong nước hồ Hoàn Kiếm theo không gian và thời gian bằng ảnh Sentinel 2. Tuyển tập Các báo cáo khoa học tại Hội nghị Các Khoa học về Trái đất.

The results of the project can be transferred to the Hanoi Environment and Natural Resource Department and the Hanoi Sewerage and Drainage One-Member State Limited Company (HSDC).

Expanding research to suburban lakes and integrating artificial intelligence into monitoring water quality in Hanoi city towards better management of natural resources and environment.