A new approach for estimation suspended sediment yield

Abstract

Abstract. A semi-distributed conceptual model, HBV-SED, for estimation of total suspended sediment concentration and yield at the outlet of a catchment was developed and tested through a case study. The base of the suspended sediment model is a dynamic hydrological model, which produces daily series of areal runoff and rainfall for each sub-basin as input to the sediment routine. A lumped measure of available sediment is accumulated continuously based on a linear relationship between log-transformed values of rainfall and erosion, while discharge of suspended sediment at the sub-basin outlet is dependent on runoff and amount of stored available sediment. Four model parameter are empirically determined through calibration against observed records of suspended sediment concentration. The model was applied to a 200 km2 catchment with high altitude differences in the tropical parts of Bolivia, where recorded suspended sediment concentrations were available during a two-year period. 10,000 parameter sets were generated through a Monte Carlo procedure to evaluate the parameter sensitivity and interdependence. The predictability of the model was assessed through dividing the data record into a calibration and an independent period for which the model was validated and compared to the sediment rating curve technique. The results showed that the slope coefficients of the log-transformed model equations for accumulation and release were much stronger than the intercept coefficients. Despite and existing interdependence between the model parameters, the HBV-SED model gave clearly better results than the sediment rating curve technique for the validation period, indication that the supply-based approached has a promising future as a tool for basic engineering applications.

Hydrological modelling of fine sediments in the Odzi River, Zimbabwe

“…The results obtained by Lidén (1999), who applied the model to a small (200 km 2 ) tropical mountainous catchment in South America, were satisfactory despite this crude model approach. However, for the semi-arid conditions in Zimbabwe and the large scale, this simplification was judged to be too crude and the following developments were suggested:…”

“…Gregory and Walling, 1973) or by the aid of empirical models. An empirically-based approach was recently suggested by Lidén (1999), who used a catchment-scale hydrological model combined with a supply-based sediment model which was calibrated against observed data to simulate riverine sediment transport. Empirically-based models usually meet the limited data availability often experienced in developing countries, but include uncertainties because of the adopted simplifications of the natural transport processes.…”

“…The HBV-SED model (Lidén, 1999) is based on the latest variant of the Hydrologiska Byråns Vattenbalansmodell (HBV-96) rainfallrunoff model , which can be classified as a semi-distributed conceptual hydrological model. It uses sub-basins as primary hydrological units in which an area-elevation distribution and a crude classification of land use (dense vegetation, open areas, and lakes) are made.…”

“…The model parameters are determined through calibration against observed riverine fine sediment concentrations. For further details about the HBV-SED the reader is referred to Lidén (1999).…”

Large-Scale Hydrological and Sediment Modeling in Nested Domains under Current and Changing Climate

“…The default option used in S-HYPE is based on the Morgan-Morgan-Finney erosion model (Morgan et al 1984) and calculates particles mobilized by rainfall energy and surface runoff, taking into account the impact of vegetation or snow on the energy. The second model is based on the Hydrologiska Byråns Vattenbalansavdelning Sediment (HBV-SED) model (Lidén 1999;Lidén et al 2001) and calculates particles mobilized by rain using a simpler index-based approach. Both WW-HYPE and E-HYPE use the HBV-SED sediment module.…”