Vu Gia - Thu Bon River bank erosion assessment (Quang Nam province) based on MIKE 21c model

Abstract

Riverbank erosion is increasingly causing negative impacts on the socio-economic development of Quang Nam province. The riverbank accretion-erosion is a natural phenomenon, reflecting the certain relationship between the flow and the channel’s characteristics through the sediment balance. Forecasting the evolution of erosion and accretion plays an important role in the sustainable development of the communities, agricultural sector as well as other sectors on both sides of the river in particular and the whole region in general. This paper presents the results of applying a set of MIKE models (MIKE11RR, HD, ST, and MIKE 21C) to simulate river bank evolution (erosion, accretion) under scenarios with 1%, 2%, 5%, and 10% flood frequencies. Comparison with the river’s bank changes in reality has shown that the simulation ability of the model is reliable enough, and suitable for the specific conditions of the Vu Gia - Thu Bon River basin. Calculation results have been mapped on the risk of riverbank erosion corresponding to flood frequency levels, and the model set also allows to extraction of accompanying information, which is the scientific basis for proposing adaptive solutions and damage reduction.