ABSTRACT
Comprehensive hydraulic analysis of Sediment Retention Ponds (SRPs) is commonly achieved through interpretation of residence time distribution curves and derivation of indices associated with short circuiting and mixing. However, the availability of various indices indicates the uncertainty in this field. This study compares some of the most commonly used hydraulic performance indices for five different flow regimes in a model SRP. The results show that the time for 5% of the total tracer quantity to exit the system more accurately shows the degree of short circuiting. Among the mixing indices, only the Morill index correctly presents the physical behaviour of the experiments. In addition, two hydraulic efficiency indices, λ and the moment index, were assessed and show a good correlation with the short circuiting and mixing indices. This study concludes that an analysis based on a combination of hydraulic indices could be more robust than relying on a single index.
