APPLICATION OF 2-D EFA MODEL TO MOBILE-BED RIVER SIMULATION

摘要

The purpose of this paper is to present the practicability of a 2-D explicit finite analytic (EFA) mobile-bed model. In the proposed model, the EFA method was used to calculate the convective terms in the flow equations, while the other terms were discretized by finite difference method. The sediment transport mode in this model was divided into bedload and suspended-load and the interaction between these two loads was considered. To show the practical applicability of this model, simulation of the aggradation and degradation of Ah-Gong-Diann Creek, Taiwan after the rehabilitation of Ah-Gong-Diann Reservoir was executed. Because most of the sediments in the watershed are fine and will flow into Ah-Gong-Diann Reservoir during floods, these fine particles will then flush into downstream Ah-Gong-Diann Creek in the suspended-load mode through desilting operation. Hence, separate calculations of bedload and suspended-load are necessary. From the case study, the degradation and aggradation tendency of the downstream Ah-Gong-Diann Creek before and after the rehabilitation, under 100-yr flood condition, can be reasonably evaluated.