SEDIMENT TRANSPORT MODEL IN SEWER NETWORKS - A NEW UTILIZATION OF THEVELIKANOV MODEL

This paper presents the application of the conceptual total load model of Velikanov through a description of the solids behaviour, its calib ration using numerical optimisation and the results on real sites. In order to take into account the full scale measurements, the Velikanov' s model has been included in a global model for solid production and t ransport in sewer system which is divided into four modules: hydrologi c, hydraulic (Muskingum model), pollution (build-up, wash off and tota l load) and calibration functions. The calibration of Velikanov parame ters has been made using a procedure of numerical optimisation based o n the Powell method. The solids behaviour is characterised by settling velocity (omega(s)) and density (a) which varies between fine particl es (omega(s)=5.4m/h and s=2.00) essentially transported in suspension and coarse particles (omega(s)=4.5m/h and s=2.65). The results of the calibration phase on three real French sites which presented dry weath er sediments and the validation phase can be considered of good qualit y. Simultaneous measurements of rainfall, hydraulic and TSS concentrat ion allowed a large range of calibration and validation. This model pr ovides a satisfying fitting of the real TSS pollutographs and this, co nsidering the global form, maximal value and the temporal position. (C ) 1998 IAWQ. Published by Elsevier Science Ltd.