Assessing trophic status of Suoi Hai Reservoir using Carlson’s Trophic State Index

Nguyen Thuy Linh, Nguyen Thi Thu Ha, Nguyen Thien Phuong Thao, Pham Quang Vinh
Author affiliations


  • Nguyen Thuy Linh Faculty of Geology, University of Science, Vietnam National University, Hanoi, Vietnam
  • Nguyen Thi Thu Ha Faculty of Geology, University of Science, Vietnam National University, Hanoi, Vietnam
  • Nguyen Thien Phuong Thao Faculty of Environmental Sciences, VNU University of Science, Vietnam National University, Hanoi, Vietnam
  • Pham Quang Vinh Institute of Geography, VAST, Hanoi, Vietnam



Eutrophication, TSI, chlorophyll-a, Secchi disk depth, Suoi Hai Reservoir


The water quality of Suoi Hai reservoir, the largest reservoir in Hanoi city, is being threatened by human activities of the surrounding area, as reported by the press. The trophic status of the reservoir is the result of both natural eutrophication and nutrient inputs from anthropogenic sources, particularly the leachate from a lakeside waste treatment plant. This study aims to identify the trophic status of the Suoi Hai reservoir and the changes of water trophic state over space and time. Data of chlorophyll-a concentration, total phosphorus, and Secchi disk depth from 51 sites during three field campaigns in October 2019, August 2020, and March 2021 was used to calculate Carlson’s trophic state index (CTSI). Resultant CTSI (ranged from 60 to 72) allows classifying Suoi Hai reservoir as highly eutrophic water. Its variations in space and time provided evidence for an influence of anthropogenic activities on the reservoir trophic state. Analysis of the trophic state index deviations suggested that total phosphorus is the key factor that influenced the reservoir trophic state. Therefore, managing the anthropogenic nutrient inputs load to the reservoir should be a critical task to control eutrophication in Suoi Hai Reservoir at present. 


Download data is not yet available.


APHA, 1998. Standard Methods for the Examination of Water and Wastewater. 20th Edition, American Public Health Association and American Water Works Association and Water Environment Federation, Washington DC, USA. Available online at:

Carlson R.E., 1977. A trophic state index for lakes. Limnology and Oceanography, 22(2), 361-369.

Carlson R.E., J. Simpson, 1996. A Coordinator’s Guide to Volunteer Lake Monitoring Methods. North American Lake Management Society, 96 pp. Available online at: /a-coordinators-guide-to-volunteer-monitoring/.

Dao T.S., Nimptsch J., Wiegand C., 2016. Dynamics of cyanobacteria and cyanobacterial toxins and their correlation with environmental parameters in Tri An Reservoir, Vietnam. Journal of Water and Health, 14(4), 699-712. /wh.2016.257.

Dat Le, Gia Bach, 2019. Ba Vi District: A need of an official inspection to assess the impacts of lakeside livestock and poultry farms on Suoi Hai reservoir’s environmental quality. Economic and Urban Electronic Newspaper.

Doan Tuan, Dang Tien, 2018. Who “killed” Suoi Hai Reservoir?. Ho Chi Minh city Police Electronic Newspaper.

Duong T.T., Jähnichen S., Le T.P.Q., Ho, C.T., Hoang T.K., Nguyen T.K., Dang D.K., 2014. The occurrence of cyanobacteria and microcystins in the Hoan Kiem Lake and the Nui Coc reservoir (North Vietnam). Environmental Earth Sciences, 71(5), 2419-2427. Doi: 10.1007/s12665-013-2642-2.

Ha N.T.T., Canh B.D., Thao N.T.P., Nhi B.T., 2016. First experience in modeling spatial distribution of chlorophyll-a concentration and TSI in the West Lake water using Sentinel-2A image. VNU Journal of Science: Earth and Environmental Sciences, 32(2S). Available online at: /EES/article/view/3016.

Ha N.T.T., Han V.T., Thao N.T.P., Khanh, D.T.M., 2017. Monitoring the trophic state index of Lake Linh Dam using Landsat 8 Imagery. Journal of Mining and Earth Sciences, 58, 42-50. Available online at: ?article =1190.

Ha N.T.T., Thao N.T.P., Koike K., Nhuan, M.T., 2017. Selecting the best band ratio to estimate chlorophyll-a concentration in a tropical freshwater lake using sentinel 2A images from a case study of Lake Ba Be (Northern Vietnam). ISPRS International Journal of Geo-Information, 6(9), 290. /ijgi6090290.

Ha T.D., 2018. Assessment of trophic state of Cao Van water reservoir. Journal of Science and Technology in Civil Engineering, 12(4), 78-85. Available online at: view/1202.

Hai N.T, Hung N.V., Hop N.V., 2019. Eutrophication concern: A case study on several lakes in Dong Ha city. Hue University Journal of Science, 128(1c), 63-68. Available online at: /index.php/hujos-ns/article/ view/5450.

Håkanson L., Bryhn A.C., Hytteborn J.K., 2007. On the issue of limiting nutrient and predictions of cyanobacteria in aquatic systems. Science of the total environment, 379(1), 89-108. 10.1016/j.scitotenv.2007.03.009.

Hoang T.H.T., Nguyen V.D., Van A.D., Nguyen H.T., 2020. Decision tree techniques to assess the role of daily DO variation in classifying shallow eutrophicated lakes in Hanoi, Vietnam. Water Quality Research Journal, 55(1), 67-78. /wqrj.2019.105.

Hop N.V., Thi P.N.A., Hoang N.H., Van V.T.B, ToT.C., 2012. Water quality and eutrophic status of the lakes in Hue citadel. Hue University Journal of Science, 73(4), 93-102. Available online at:

Hung N.T., Huyen N.T.T., 2010. Studying on water quality of Dai Lai reservoir by one year of field investigation and data collection. Journal of Water Resources and Environmental Engineering, 31, 1-8. Available online at: http://tapchivatuyentap.tlu. 2030/So%203100010.pdf.

Istvánovics V., 2010. Eutrophication of Lakes and Reservoirs. In: Gene E. Likens, (Editor) Encyclopedia of Inland Waters, Oxford: Elsevier, 1, 157-165. Doi: 10.1016/B978-012370626-3.00141-1.

Kumar P., Mahajan A.K., Meena N.K., 2019. Evaluation of trophic status and its limiting factors in the Renuka Lake of Lesser

Himalaya, India. Environmental monitoring and assessment, 191(2), 105. /s10661-019-7247-0.

Linh N.T., Hoa N.T., Tu D.T., Vinh P.Q., Ha N.T.T., 2020. Evaluating and monitoring eutrophication in Truc Bach Lake in space and time using Sentinel 2A image. Journal of Environmental Economics, 166, 11-17. Available online at:

Linh N.T., Thao P.T.H., Phuong L.T., Han V.T., Ha N.T.T., Vinh P.Q., 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. 4471.

Mamun M., Kim J.Y., An K.G., 2021. Multivariate Statistical Analysis of Water Quality and Trophic State in an Artificial Dam Reservoir. Water, 13(2), 186. /10.3390/w13020186.

Naumann E., 1929. The scope and chief problems of regional limnology. Internationale Revue der gesamten Hydrobiologie und Hydrographie, 22(1), 423-444. 1002/iroh.19290220128.

Ngatia L., Taylor R., 2018. Phosphorus eutrophication and mitigation strategies. In Phosphorus-Recovery and Recycling. IntechOpen. Doi: 10.5772/intechopen.79173.

Ngoc N.T.B., An V.D., Quynh L.T.P., Thuy N.B., Nghia L.D., Thuy D.T., Cuong H.T., 2017. Assessment of the trophic status in some lakes within Hanoi inner city. Vietnam Journal of Science and Technology, 55(1), 84-92. /55/1/8575.

Nguyen T.H.H., Pham T.B.D., Dang T.L., Nguyen N.T., Nguyen D.T., Pham T.M., Tran D.K., 2015. Microalgae as indicators of eutrophication in Hoan Kiem lake, Hanoi, Vietnam. Vietnam Journal of Biotechnology, 13(2), 355-365. Available online at:

Okech E.O., Kitaka N., Oduor S.O., Verschuren D., 2018. Trophic state and nutrient limitation in Lake Baringo, Kenya. African Journal of Aquatic Science, 43(2), 169-173. /16085914.2018.1462139.

Pavluk T., Bij D.V.A., 2013. Trophic index and efficiency. In Reference Module in Earth Systems and Environmental Sciences,1-9. Doi: 10.1016/B978-0-12-409548-9.00608-4.

Pham T.L., Dao T.S., Shimizu K., Lan-Chi D.H., Utsumi M., 2015. Isolation and characterization of microcystin-producing cyanobacteria from Dau Tieng Reservoir, Vietnam. Nova Hedwigia, 101(1-2), 3-20. Doi: 10.1127/nova_hedwigia/2014/0243.

Prasad D., Siddaraju G., 2012. Carlson’s Trophic State Index for the assessment of trophic status of two Lakes in Mandya district. Advances in Applied Science Research, 3(5), 2992-2996. Available online at:

Thuan T.D., Lap B.Q., 2018. Some characteristics of eutrophication in a shallow lake in Hanoi. Journal of Water Resources and Environmental Engineering, 61, 52-61. Available online at: /index.php/DHTL/article/view/36470.

Tien N.T.H., Van N.S., Nguyen V.T.H., Thoa K.T., Tuan N.D., Van K.V., 2018. Current status of water quality, sediments of West Lake (Ha Noi) and some solutions for aquatic resources conservation. Vietnam Journal of Agricultural Science, 16(5), 464-472. Available online at: /wp-content/uploads/2018/10/T%E1%BA%A1p-ch %C3%AD-%E1%BB%91-5.464-4721.pdf.

Toan V.D., 2012. Assess the impact of Xuan Son landfill to water environment and solution proposed. Journal of Water Resources and Environmental Engineering, 39, 28-33. Available online at: 005.pdf.

Trung B., Dao T.S., Faassen E., Lürling M., 2018. Cyanobacterial blooms and microcystins in Southern Vietnam. Toxins, 10(11), 471. 10.3390/toxins10110471.

Trung N.H., Hop N.V., 2020. Assessment of water quality and eutrophication status at several lakes in Da Nang city. Hue University Journal of Science, 16(2), 31-41. Available online at: http://joshusc. Hop.pdf.

Tuan D.H., Mung V.T., Cuong D.M., 2017. Evaluation of water quality of a Blue Lake at An Son commune, Thuy Nguyen district, Hai Phong city by Water Quality Index (WQI), Trophic State Index (TSI) and Heavy Metal Pollution Index (HPI). VNU Journal of Science: Earth and Environmental Sciences, 33(1S), 45-54. 4147.

Vietnam Ministry of Science and Technology, 2008. Vietnam National Standards: Water quality - Determination of phosphorus - Ammonium molybdate spectrometric method, code: TCVN- 6202:2008 (ISO 6878: 2004). Available online at: /tieuchuan/view?sohieu=TCVN+6202%3A2008.

Vinh P.Q., Ha N.T.T., Binh N.T., Thang N.N., Oanh L.T., Thao N.T.P., 2019. Developing algorithm for estimating chlorophyll-a concentration in the Thac Ba Reservoir surface water using Landsat 8 Imagery. Vietnam Journal of Earth Sciences, 41(1), 10-20. 13542.

Vollenweider R.A., Giovanardi F., Montanari G., Rinaldi A., 1998. Characterization of the trophic conditions of marine coastal waters with special reference to the NW Adriatic Sea: proposal for a trophic scale, turbidity and generalized water quality index. Environmetrics: The official journal of the International Environmetrics Society, 9(3), 329-357. /06)9:3<329::AID-ENV308>3.0.CO;2-9.

Vollenweider R.A., Kerekes J., 1982. Eutrophication of waters. Monitoring, assessment and control. Organization for Economic Co-Operation and Development (OECD), Paris, 156p.

Yen T.T.H., Luom L.T., Luu P.T., 2019. Assessing Eutrophic Status and Environmental Factor Regulating Green Algae Community in Tri An Reservoir. Vietnam Journal of Agricultural Science, 17(8), 645-664. Available online at: /2019/12/so-8.2.6.pdf.

Youcai Z., 2018. Chapter 1 - Leachate generation and characteristics. Pollution Control Technology for Leachate from Municipal Solid Waste. Butterworth-Heinemann, 1-30.

Zhang Z.S., Mei Z.P., 1996. Effects of human activities on the ecological changes of lakes in China. GeoJournal, 40(1), 17-24. Available online at: /41146969.




How to Cite

Nguyen Thuy, L., Nguyen Thi Thu, H., Nguyen Thien Phuong, T., & Pham Quang, V. (2021). Assessing trophic status of Suoi Hai Reservoir using Carlson’s Trophic State Index. Vietnam Journal of Earth Sciences, 43(4), 509–523.