*5.2. Calculation of Sediment Transport in Estuaries*

SWE models for the free-surface flow and sediment transport may be divided into three kinds, which are the Level-1 (the so-called "coupled" model), Level-2 (decoupled model with timely riverbed update, which is used in this paper), and Level-3 (decoupled model using a morphological scale factor) models. These models are compared as follows.
