Estimation of suspended sediment rating curves in the Ca river basin, Vietnam

This paper presents an estimation of sediment rating curves in the Ca river basin, Vietnam using the daily data of suspended sediment concentration (SSC) and water discharge (Q) collected in the period from 2009 to 2019. Linear, non-linear, and log-linear regressions between SSC and Q are tested for three studied locations. Coefficients in each type of regression are carefully determined based on five statistical indices. The results showed that all three regressions represented acceptably observed values of SSC. The magnitude of Pearson's correlation coefficient was about 0.82, while the coefficient of determination of SSC equaled 0.64. The dimensional statistical errors of estimated values of SSC were less than 5.25% of the observed magnitude of SSC at locations. The correlation between SSC and Q at considered locations indicated that the magnitude of the wavelet coefficient for the SSC time series showed the main periodicity at two months and seasonal timescales.