EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Agricultural colonization of dynamic riverine islands in a tropical wandering river

Livia Serrao1, Luz Elita Balcázar Terrones2,3, Hugo Alfredo Huamaní Yupanqui2, Juan Pablo Rengifo Trigozo4, and Guido Zolezzi1
Livia Serrao et al.
  • 1University of Trento, Department of Civil, Environmental and Mechanical Engineering - DICAM, Italy
  • 2Universidad Nacional Agraria de la Selva - UNAS, Departamento de Ciencias Agrarias, Peru
  • 3Instituto de Investigación de la Amazonía Peruana - IIAP, Peru
  • 4Universidad Nacional Agraria de la Selva - UNAS, Departamento de Conservación de Suelos y Agua, Peru

We investigate the interplay between riverine islands dynamics in a large tropical wandering river and their use by local communities for agricultural production. The study focuses on a piedmont reach of the Huallaga river, which drains the Peruvian Amazon. Riverine islands are characterized by a high space-time variability in active wandering river systems like the Huallaga, which results from biophysical interactions among flow, sediment transport and riparian vegetation. Despite the rapid rates of planform changes, islands in the Huallaga are extensively used by local farmers who mainly rely on rainfed, low tech agriculture. Thanks to the high nutrient availability in their soil, dynamic riverine islands are offering a natural solution to the advancing degradation of soils due to the progressive increase of intensive monoculture in nearby floodplain areas. The possibility of using intact fields, rich in organic matter, pushes the local populations to colonize riverine islands, challenging their dynamism and high erosion. Through a combination of participatory surveys, field measurements and remote sensing analysis of the recent (30 years) reach-scale island dynamics we investigate whether the benefits of cropping in a riverine island are more relevant than the damages related to their intense morpho-dynamics. Challenges to such biophysical-social system are posed by planned and ongoing infrastructural development in the catchment, affecting the flow and sediment supply regimes.

How to cite: Serrao, L., Balcázar Terrones, L. E., Huamaní Yupanqui, H. A., Rengifo Trigozo, J. P., and Zolezzi, G.: Agricultural colonization of dynamic riverine islands in a tropical wandering river, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-20579,, 2020

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Display material version 1 – uploaded on 02 May 2020
  • CC1: Comment on EGU2020-20579, R.Valli Divya, 08 May 2020

    What are the main bio-physical/chemical factors influencing the Huallaga riverine islands?

    • AC1: Reply to CC1, Livia Serrao, 08 May 2020

      We investigated the main chemical and physical soil factors which can impact the agricultural suitability: texture (sand, clay, silt), pH, Organic Matter, N, available P, K, Cation-Interchange Capacity, exchangeable Ca, Mg, K, Na, penetrability, and infiltration capacity.

      We cannot state which ones are the most important, yet. We used them as parameters to understand if the river morphodynamics history can be intended as a positive driver for agricultural suitability in fluvial islands. So far, we observed a likely correlation between river morphodynamics and available P, CEC and pH.