Dynamic modeling of the interaction of riparian vegetation with floods and application to vegetation management

Abstract Various types of numerical models have been developed to evaluate the colonization and succession of riparian vegetation. Two types of models are applied for this purpose: one type analyzes the succession of the vegetation phase in accordance with flooding conditions; the other analyzes the vegetation dynamically. Both types of models are based on evaluations of the influence of physical factors such as the quantity of flow, the water level, the shear-stress and riverbed shape, etc. While the condition of the vegetation is important for simulating the channel morphology, it cannot be suitably evaluated without a dynamic growth model that considers the mortality of the vegetation and the effect of the vegetation on the roughness during floods. In this study we developed a new riparian vegetation model by combining the Dynamic Riparian Vegetation Model (DRIPVEM) with models to simulate river-bed deformation and changes in resistance during flood events. The modified DRIPVEM was applied to predict the phenomena expected to come with global warming, such as the effects stemming from the increased growth rates of woody plants, flow rates in river channels, and eutrophication of river water. The model was also used to evaluate the maintenance cost of vegetation management. Our results indicated that the cost of vegetation harvesting performed every 5 years was 2.5 times higher than the cost of yearly harvesting. The dynamic model was found to be extremely useful, and requisite for the effective and efficient management of the riparian vegetation.