Analysis of Sediment Dynamics in a River Basin Using a Process-based Approach

Modelling of sediment dynamics for developing best management practices of soil erosion and sediment control has become inevitable for sustainable management of watersheds. Different hydrological processes govern sediment dynamics in a river basin which are highly variable in spatial and temporal scales. The study aims to develop a process-based sediment dynamic model at river basin scale by integrating sediment processes (soil erosion, transport and deposition) with an existing process-based distributed hydrological model. Water flow and sediment transport at different surface grids and river nodes are modelled using one dimensional kinematic wave approximation of Saint-Venant equations. The mechanics of sediment dynamics are considered by adopting suitable physical equations representing different processes after a comprehensive review. The model has been tested on Abukuma river basin, Japan. Results indicate that the model simulates basin hydrology and its associated sediment dynamics reasonably well through relevant statistical checks (Nash-Sutcliffe efficiency and R-squared value). The paper presents the model including description of different steps and the results of its application on case study area.