Neck cutoffs may affect the town of Jenaro Herrera in the Ucayali River (Peru)
Cover figure: Potential neck cutoff mechanisms for the Ucayali River near Jenaro Herrera town. Figure from Abad et al. (2022)
In our publication, “Planform Dynamics and Cut-Off Processes in the Lower Ucayali River, Peruvian Amazon”, we describe two potential mechanisms for the occurrence of neck cutoffs near the town of Jenaro Herrera in the Ucayali River. These two mechanisms are:
- the continuous migration of the bend upstream near Santa Rosa town, which could recover the paleochannels (Vainilla, Sahua, and Supay lakes), and
- the migration of the bend that has been constantly reducing the distance between them, near Nuevo Progreso town.
Credits: Hernan Gonzales and Marco Paredes (SENAMHI-Peru).
Methodology
We used a combination of remote sensing techniques, hydrogeomorphological measurements (water flows and sediment characterization [suspended, bottom, and banks], morphology), and morphodynamic models, to describe the physical processes in the Ucayali River near the town of Jenaro Herrera. For more information about the methods used, see the references below:
- Characterization of modern river dynamics: Abad et al (2022), Abad et al (2023), Valverde et al. (2024)
- Characterization of ancient fluvial dynamics: Rojas et al (2023)
- Mathematical modeling in large rivers: Frias et al. (2015), Mendoza et al. (2016), Li et al. (2023)
Results
Two potential mechanisms for a meander cutoff that would affect the town of Jenaro Herrera were identified. If one of these mechanisms occurs, important changes would be observed in the planform dynamics of the Ucayali River, with direct impacts on Jenaro Herrera. The town of Jenaro Herrera is located in an elevated area along the right bank of the Ucayali River and, potentially, it may not suffer direct erosion from the river. Still, it might be subject to river isolation (especially if the second mechanism occurs). The smaller towns in this area may require relocation considering the mechanism to be developed and how the Ucayali River might adapt after the meander cutoff. Therefore, we recommend carrying out constant monitoring (measurements and modeling) and developing adaptation planning and activities in response to this natural process regarding river transportation and sanitation services.
Citation
Abad, J. D., Mendoza, A., Arceo, K., Torres, Z., Valverde, H., Medina, G., Frias, C., Berezowsky, M. (2022). Planform Dynamics and cut-off processes in the Lower Ucayali River, Peruvian Amazon. Water, 11, 3059. https://doi.org/10.3390/w14193059