Analyze Streamflow and Suspended Sediment Load in Upstream Stations of the Cuu Long River
Main Article Content
Abstract
In recent years, the Mekong Delta - the downstream region of the Mekong River system has experienced pronounced alterations in streamflow regime and sediment transport. Hydrological monitoring data from stations reveal significant trends in water level and discharge at stations along the main channels of the Tien and Hau Rivers, as well as their major tributaries, particularly in the flood season. The amount of suspended sediment transported downstream has shown a decreasing trend compared to the long-term average of previous decades. This paper applies the non-parametric Mann–Kendall test in combination with Sen’s slope estimator to assess the trends in streamflow characteristics (water level and discharge) and suspended sediment at two upstream stations of the Mekong Delta: Tan Chau (in the Tien River) and Chau Doc (in the Hau River). The results indicate a decreasing trend in water levels at both stations, with Tan Chau declining by 4.85 cm/year and Chau Doc declining by 3.43 cm/year. At Chau Doc, maximum discharge (Qmax) decreased by 71.25 m³/s/year and average discharge (Qave) decreased by 46 m³/s/year, respectively, while discharge trends at Tan Chau did not reach the 95% significance level.
Keywords:
Flow characteristics, sediment, Mekong River, Mann–Kendall, Sen’s slope.
References
[1] C. T. Van et al., Assessment of Changes in Surface Runoff at Characteristic Sites in the Dong Thap Muoi Area. Hydro-Meteorology Journal, Vol. 692, 2018, pp 19-25 (in Vietnamese).
[2] T. H. Thai et al., Changes in River Flow in the Mekong Delta, Hydro-Meteorology Journal,
Vol. 7-2014 (in Vietnamese).
[3] L. V. Ninh et al., Study on the Development of a Meteorological and Hydrological Database for An Giang Province in the Context of Climate Change, Final Summary Report of the Province Science and Technology Project (in Vietnamese), 2018.
[4] L. V. Ninh, N. M. Giam, Climate Features of An Giang Province, Hydro-Meteorology journal, 12/2017, pp 18-26 (in Vietnamese).
[5] C. T. Van, N. T. Son, Hydrological and Hydraulic Modeling of the Mekong River Delta to Assess the Impact of the Dike System on Surface Runoff Changes in the Dong Thap Muoi Area, VNU Science Journal: Earth and Environmental Sciences, Vol. 32, 3S, 2016 (in Vietnamese).
[6] N. T. P. Mai, Impacts of Upstream Dams on Salinity Dynamics in the Mekong River Estuary Region, Journal of Water Resources and Environmental Engineering, Vol. 58, 2017 (in Vietnamese).
[7] N. V. Manh et al., Large-scale Suspended Sediment Transport and Sediment Deposition in the Mekong Delta. HESS (in Vietnamese).
[8] T. Q. Toan, T. D. Thang, Analysis of the Impacts of Upstream Reservoirs on Dry-Season Hydrological Changes in the Mekong Delta, Journal of Water Resources Science and Technology Vol. 31, 2016 (in Vietnamese).
[9] T. Q. Toan et al., Study on the Assessment of the Impacts of Cascade Hydropower Projects on the Mainstream of the Lower Mekong River on Flow Regime, Environment, and Socio-Economic Conditions in the Mekong Delta, and Proposed Mitigation Measures, Final Summary Report of the National Science and Technology Project, KC, Vol. 08, No. 13, 2016, pp. 11-15 (in Vietnamese).
[10] D. V. Duy et al., Assessing River Corridor Stability and Erosion Dynamics in the Mekong Delta: Implications for Sustainable Management, Earth, Vol. 6, No. 2, 2025, pp. 34,
https://doi.org/10.3390/earth6020034.
[11] T. Tamura et al., Long-term Sediment Decline Causes Ongoing Shrinkage of the Mekong Megadelta, Vietnam, Scientific Reports, Vol. 10, 2020, https://doi.org/10.1038/s41598-020-64630-z.
[12] C. T. Da et al., Farmers’ Perceived Impact of High-Dikes on Rice and Wild Fish Yields, Water Quality, and Use of Fertilizers in the Mekong Delta, Vietnam, Published as part of ACS ES&T Water Virtual Special Issue Navigating Challenges and Charting Solutions of Water Issues in South East Asia, 2024.
[13] V. H. T. Pham, et al., Impact of Water Resources Variation on Winter–Spring Rice Yield in the upper Vietnamese Mekong Delta: A Case Study of An Giang Province. Irrigation & Drainage, Vol. 73, 2024, pp. 574-587.
[14] V. T. Linh et al., Application of Modeling to Assess Flood and Salinity Intrusion Trends under Climate Change: A Pilot Study in Ho Chi Minh City, Hydro-Meteorology Journal, 2019,
pp. 98-110 (in Vietnamese).
[15] N. V. Tin, Assessment of Long-Term Rainfall Trends in Peak Periods in Ho Chi Minh City (1971–2016) Using the Non-Parametric Mann-Kendall Test, Hydro-Meteorology Journal,
Vol. 11, 2017, pp. 52-55 (in Vietnamese).
[16] N. D. Thanh et al., Assessment of Trends in Selected Meteorological Parameters (1961–2007) Using Non-Parametric Tests, Journal of Science, Vietnam National University – Hanoi, Natural Sciences and Technology, Vol. 28, 2012,
pp. 129-135 (in Vietnamese).
[17] N. V. Tin, C. T. Van, et al., Analysis of Rainfall Trend Changes in the Central Highlands Region during 1990–2021, Hydro-Meteorology Journal, Vol. 744, No. 1, 2022, pp 15-25, https://doi.org/10.36335/VNJHM.2022(744(1)).15-25 (in Vietnamese).
[18] P. V. Tan et al., Trends and Magnitude of Extreme Temperature Changes in Vietnam During 1961–2007, Journal of Science, Vietnam National University – Hanoi, Natural Sciences and Technology, Vol. 25, No. 3S, 2009, pp. 412-422 (in Vietnamese).
[19] D. T. N. Canh et al., Nonparametric Estimation Approach for Evaluating the Trend of Hydro-Meteorological Factors in Quang Nam-Da Nang, Journal of Science and Technology – University of Danang, 2021, pp. 8-13 (in Vietnamese).
[20] F. F. Chacón, D. P. Velázquez, J. J. Sánchez, P. J. Sáez, A. J. C. Lara, J. A. L. Espinar, Trends Analysis of Precipitation and Temperature in the Alto Genil Basin (Southeast Spain) from 1970 to 2010, in EGU General Assembly Conference Abstracts, 2016, pp. EPSC2016-14606.
[21] Ü. Güner Bacanli, Trend Analysis of Precipitation and Drought in the Aegean Region, Turkey, Meteorological Applications, Vol. 24, No. 2, 2017, pp. 239-249.
[22] P. T. Minh et al., Applying the Mann-Kendall Method to Test the Change Trend of Rainfall and Temperature in Bac Lieu Province 1980-2022, VNUHCM Journal of Earth Science Environment, Vol. 8, No. 2, 2024, pp. 975-987 (in Vietnamese).
[23] A. Mustapha, Detecting Surface Water Quality Trends Using Mann-Kendall Tests and Sen’s Slope Estimates, International Journal of Agriculture Innovations Research, Vol. 1, 2013, pp. 108-114.
[24] R. Yadav, S. Tripathi, G. Pranuthi, S. Dubey, Trend Analysis by Mann-Kendall Test for Precipitation and Temperature for Thirteen Districts of Uttarakhand, Journal of Agrometeorology, Vol. 16, 2014, No. 2, pp. 164-171.
[25] J. Mallick et al., Analysing the Trend of Rainfall in Asir Region of Saudi Arabia Using the Family of Mann-Kendall Tests, Innovative Trend Analysis, and Detrended Fluctuation Analysis, Theoretical Applied Climatology, Vol. 143, 2021, No. 1,
pp. 823-841.
[26] F. Aditya, E. Gusmayanti, J. Sudrajat, Rainfall Trend Analysis Using Mann-Kendall and Sen’s Slope Estimator Test in West Kalimantan, IOP Conference Series: Earth and Environmental Science, IOP Publishing, Vol. 893, 2021, No. 1,
pp. 012006
[27] A. Marsick, H. André, I. Khelf, Q. Leclère, J. Antoni, Benefits of Mann–Kendall Trend Analysis for Vibration-Based Condition Monitoring, Mechanical Systems Signal Processing, Vol. 216, 2024, pp. 111486.
[28] S. Alashan, Non-monotonic Trend Analysis Using Mann–Kendall with Self-Quantiles, Theoretical and Applied Climatology, Vol. 155, No. 2, 2024, pp. 901-910.
[29] M. G. Kendall, Rank Correlation Methods, 1948.
[30] R. O. Gilbert, Statistical Methods for Environmental Pollution Monitoring, John Wiley & Sons, 1987.
[2] T. H. Thai et al., Changes in River Flow in the Mekong Delta, Hydro-Meteorology Journal,
Vol. 7-2014 (in Vietnamese).
[3] L. V. Ninh et al., Study on the Development of a Meteorological and Hydrological Database for An Giang Province in the Context of Climate Change, Final Summary Report of the Province Science and Technology Project (in Vietnamese), 2018.
[4] L. V. Ninh, N. M. Giam, Climate Features of An Giang Province, Hydro-Meteorology journal, 12/2017, pp 18-26 (in Vietnamese).
[5] C. T. Van, N. T. Son, Hydrological and Hydraulic Modeling of the Mekong River Delta to Assess the Impact of the Dike System on Surface Runoff Changes in the Dong Thap Muoi Area, VNU Science Journal: Earth and Environmental Sciences, Vol. 32, 3S, 2016 (in Vietnamese).
[6] N. T. P. Mai, Impacts of Upstream Dams on Salinity Dynamics in the Mekong River Estuary Region, Journal of Water Resources and Environmental Engineering, Vol. 58, 2017 (in Vietnamese).
[7] N. V. Manh et al., Large-scale Suspended Sediment Transport and Sediment Deposition in the Mekong Delta. HESS (in Vietnamese).
[8] T. Q. Toan, T. D. Thang, Analysis of the Impacts of Upstream Reservoirs on Dry-Season Hydrological Changes in the Mekong Delta, Journal of Water Resources Science and Technology Vol. 31, 2016 (in Vietnamese).
[9] T. Q. Toan et al., Study on the Assessment of the Impacts of Cascade Hydropower Projects on the Mainstream of the Lower Mekong River on Flow Regime, Environment, and Socio-Economic Conditions in the Mekong Delta, and Proposed Mitigation Measures, Final Summary Report of the National Science and Technology Project, KC, Vol. 08, No. 13, 2016, pp. 11-15 (in Vietnamese).
[10] D. V. Duy et al., Assessing River Corridor Stability and Erosion Dynamics in the Mekong Delta: Implications for Sustainable Management, Earth, Vol. 6, No. 2, 2025, pp. 34,
https://doi.org/10.3390/earth6020034.
[11] T. Tamura et al., Long-term Sediment Decline Causes Ongoing Shrinkage of the Mekong Megadelta, Vietnam, Scientific Reports, Vol. 10, 2020, https://doi.org/10.1038/s41598-020-64630-z.
[12] C. T. Da et al., Farmers’ Perceived Impact of High-Dikes on Rice and Wild Fish Yields, Water Quality, and Use of Fertilizers in the Mekong Delta, Vietnam, Published as part of ACS ES&T Water Virtual Special Issue Navigating Challenges and Charting Solutions of Water Issues in South East Asia, 2024.
[13] V. H. T. Pham, et al., Impact of Water Resources Variation on Winter–Spring Rice Yield in the upper Vietnamese Mekong Delta: A Case Study of An Giang Province. Irrigation & Drainage, Vol. 73, 2024, pp. 574-587.
[14] V. T. Linh et al., Application of Modeling to Assess Flood and Salinity Intrusion Trends under Climate Change: A Pilot Study in Ho Chi Minh City, Hydro-Meteorology Journal, 2019,
pp. 98-110 (in Vietnamese).
[15] N. V. Tin, Assessment of Long-Term Rainfall Trends in Peak Periods in Ho Chi Minh City (1971–2016) Using the Non-Parametric Mann-Kendall Test, Hydro-Meteorology Journal,
Vol. 11, 2017, pp. 52-55 (in Vietnamese).
[16] N. D. Thanh et al., Assessment of Trends in Selected Meteorological Parameters (1961–2007) Using Non-Parametric Tests, Journal of Science, Vietnam National University – Hanoi, Natural Sciences and Technology, Vol. 28, 2012,
pp. 129-135 (in Vietnamese).
[17] N. V. Tin, C. T. Van, et al., Analysis of Rainfall Trend Changes in the Central Highlands Region during 1990–2021, Hydro-Meteorology Journal, Vol. 744, No. 1, 2022, pp 15-25, https://doi.org/10.36335/VNJHM.2022(744(1)).15-25 (in Vietnamese).
[18] P. V. Tan et al., Trends and Magnitude of Extreme Temperature Changes in Vietnam During 1961–2007, Journal of Science, Vietnam National University – Hanoi, Natural Sciences and Technology, Vol. 25, No. 3S, 2009, pp. 412-422 (in Vietnamese).
[19] D. T. N. Canh et al., Nonparametric Estimation Approach for Evaluating the Trend of Hydro-Meteorological Factors in Quang Nam-Da Nang, Journal of Science and Technology – University of Danang, 2021, pp. 8-13 (in Vietnamese).
[20] F. F. Chacón, D. P. Velázquez, J. J. Sánchez, P. J. Sáez, A. J. C. Lara, J. A. L. Espinar, Trends Analysis of Precipitation and Temperature in the Alto Genil Basin (Southeast Spain) from 1970 to 2010, in EGU General Assembly Conference Abstracts, 2016, pp. EPSC2016-14606.
[21] Ü. Güner Bacanli, Trend Analysis of Precipitation and Drought in the Aegean Region, Turkey, Meteorological Applications, Vol. 24, No. 2, 2017, pp. 239-249.
[22] P. T. Minh et al., Applying the Mann-Kendall Method to Test the Change Trend of Rainfall and Temperature in Bac Lieu Province 1980-2022, VNUHCM Journal of Earth Science Environment, Vol. 8, No. 2, 2024, pp. 975-987 (in Vietnamese).
[23] A. Mustapha, Detecting Surface Water Quality Trends Using Mann-Kendall Tests and Sen’s Slope Estimates, International Journal of Agriculture Innovations Research, Vol. 1, 2013, pp. 108-114.
[24] R. Yadav, S. Tripathi, G. Pranuthi, S. Dubey, Trend Analysis by Mann-Kendall Test for Precipitation and Temperature for Thirteen Districts of Uttarakhand, Journal of Agrometeorology, Vol. 16, 2014, No. 2, pp. 164-171.
[25] J. Mallick et al., Analysing the Trend of Rainfall in Asir Region of Saudi Arabia Using the Family of Mann-Kendall Tests, Innovative Trend Analysis, and Detrended Fluctuation Analysis, Theoretical Applied Climatology, Vol. 143, 2021, No. 1,
pp. 823-841.
[26] F. Aditya, E. Gusmayanti, J. Sudrajat, Rainfall Trend Analysis Using Mann-Kendall and Sen’s Slope Estimator Test in West Kalimantan, IOP Conference Series: Earth and Environmental Science, IOP Publishing, Vol. 893, 2021, No. 1,
pp. 012006
[27] A. Marsick, H. André, I. Khelf, Q. Leclère, J. Antoni, Benefits of Mann–Kendall Trend Analysis for Vibration-Based Condition Monitoring, Mechanical Systems Signal Processing, Vol. 216, 2024, pp. 111486.
[28] S. Alashan, Non-monotonic Trend Analysis Using Mann–Kendall with Self-Quantiles, Theoretical and Applied Climatology, Vol. 155, No. 2, 2024, pp. 901-910.
[29] M. G. Kendall, Rank Correlation Methods, 1948.
[30] R. O. Gilbert, Statistical Methods for Environmental Pollution Monitoring, John Wiley & Sons, 1987.