NUMERICAL MODEL FOR MOVABLE BED AS A TOOL FOR THE SIMULATION OF THE RIVER EROSION A CASE STUDY
Keywords:numerical movable bed model, bed load transport, dredging, erosion.
A serious erosion problem takes place in Cipamingkis River in west Java, Indonesia. As a consequence, river protection works are frequently damaged. The process is probably caused by sand and gravel dredging activities in the river downstream. This problem has not been treated until now. In an attempt to find an appropriate solution, a numerical model to simulate th interaction between bed load transport and bed stability has been developed. At first, the fixed bed model was developed and calibrated using measured water level data from the Rhein river in Germany. By means of this model, a movable bed model has then been developed. The rate of the bed load transport in Cipamingkis river was calculated using Meyer-Peter and Müller formula. For this, the monthly average flood event was chosen as boundary conditions. In order to forecast the effects of existing weir and dredging, the movable bed model has been applied for three different conditions: river without weir and dredging, river with weir and without dredging, an river with weir and dredging. The result shows that the developed model is capable to predict the interaction between bed load transport and bed stability.