Author(s): Kensuke Naito; Toshiki Iwasaki; Leo Guerrero; Henry Valverde; Yulissa Estrada; Jorge D. Abad
Linked Author(s): Jorge D. Abad
Keywords: Meander cutoff; Channel degradation; Dredging; Numerical modeling
Abstract: In this study, an anticipated meander cutoff in the Huallaga River, a meandering river in Peruvian Amazon, is investigated. Approximately 80 km of the study reach includes several sites where channel dredging is planned to improve navigability. All these sites are located upstream of the anticipated meander cutoff point, which is approximately 75 km downstream from Yurimaguas. Due to the increasing concern about negative environmental impacts, alternative measure is sought. Natural channel degradation due to the meander cutoff is hence expected to replace the artificial river modification. In this study we study progradation of the upstream bed degradation and the downstream bed aggradation triggered by the cutoff. A simple two-dimensional numerical model is developed to achieve the objective. Prior to the model development, field measurements are conducted in order to obtain model input parameters such as channel geometry, water discharge, suspended load, bed load, bed material size and hydraulic resistance. Based on the model results, discussions are made in terms of the possibility to replace the artificial channel modification (i.e. dredging) with natural channel modification due to the meander cutoff to improve the channel navigability.
Year: 2020