UBC Theses and Dissertations
Statistical modelling of sediment concentration Thompson, Mai Phuong
One technique that is commonly used to replace the costly daily sampling of sedimentconcentration in assessing sediment discharge is the "rating curve" technique. This technique relies on the form of the relationship between sediment concentration and water discharge to estimate long-term sediment loads. In this study, a regression/time-series approach to modelling the relationship between sediment concentration and water discharge is developed. The model comprises of a linear regression of the natural logarithm of sediment concentration on the natural logarithm of water discharge and an autoregressive time-series of order one or two for the errors of the regression equation. The main inferences from the model are the estimation of annual sediment loads and the calculation of their standard errors. Bias correction factors for the bias resulted from the inverse transformation of the natural logarithm of sediment concentration are studied. The accuracy of the load estimates is checked by comparing them to figures published by Water Survey of Canada.