Analyze Streamflow and Suspended Sediment Load in Upstream Stations of the Cuu Long River

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.