Author(s): Naoki Kuroda; Shoji Hirao; Takashi Asaeda
Linked Author(s): Takashi Asaeda
Keywords: No Keywords
Abstract: Vegetation of a river channel has an extremely large effect on the channel morphology. In order to secure and improve the safety level of flood control of rivers, and conservation and restoration of river environments, the river channel management based on the growth and succession of vegetation and trees is important. In this paper, the authors propose a vegetation growth model (DRIPVEM: Dynamic Riparian Vegetation Model) that considers nutrient cycling in the growth process of herbaceous plants and trees, as a tool to contribute to the effective maintenance and management of river channels. Also, this model is aimed to predict the morphological changes of river channels associated with growth and expansion of herbaceous plants and trees. The model verification was done by simulating the flow condition and river bed deformation at the time of large-scale flooding and the growth situation of vegetation and trees against the long-term flow condition on the sandbars in the Arakawa Kumagaya area（Japan） where the authors continuously studied (Fig. 1). A prediction model was developed based on the nutrient budget to analyse the influence of growth and expansion of herbaceous plants and trees caused by flood flow and river bed deformation. In order to simply grasp the influence of eutrophication induced by the developments within the river basin (livestock, agriculture etc. ), the sensitivity analysis was conducted to understand soil nitrogen in the sandbar. According to the analysis, it was confirmed that the growing area of robinia decreases as the initial nitrogen content of soil increases (Fig. 2). This study indicated that in the management of vegetation and woody plants growth in river channel, the vegetation control not only by the physical environment such as hydraulic quantity and river bed deformation, but also by the water quality management is possible and necessary.
Year: 2018