Evolución geomorfológica de canales distributarios en el frente sudoriental del delta del Paraná (Tigre, Buenos Aires, Argentina)

Geomorphological evolution of distributary channels in the southeastern front of the Paraná delta (Tigre, Buenos Aires, Argentina)

Agustín Quesada1,2,*, Silvia C. Marcomini1,2

1 Departamento de Ciencias Geológicas, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires. Intendente Güiraldes 2160 Buenos Aires, 1428, Argentina.

2 Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad de Buenos Aires. Intendente Güiraldes 2160 Buenos Aires, 1428, Argentina.

* Autor para correspondencia: (A. Quesada) This email address is being protected from spambots. You need JavaScript enabled to view it.  

How to cite this article:

Quesada, A., Marcomini, S.C., 2025, Evolución geomorfológica de canales distributarios en el frente sudoriental del delta del Paraná (Tigre, Buenos Aires, Argentina): Boletín de la Sociedad Geológica Mexicana, 77(3), A110925. http://dx.doi.org/10.18268/BSGM2025v77n3a110925  

Manuscript received: December 10, 2024. Corrected manuscript received: July 27, 2025. Manuscript accepted: August 4, 2025.

ABSTRACT

The geomorphological evolution of the distributary channels in the southeastern front of the Paraná Delta ( first section of islands, Tigre District) results from the interaction between fluvial and coastal processes. This region is characterized by a drainage network composed of a main trunk distributary channel (the Paraná de las Palmas River, the main navigable route of the Paraná–Emilio Mitre waterway), secondary and terminal distributary channels, as well as smaller tidal and erosional channels that drain the interdistributary islands. More than ten landforms associated with active dynamics of the delta front and the lower delta plain were identified. Based on the analysis of aerial and historical images, a two-phase evolutionary model is proposed: a first phase of channel formation at the advancing front, where the attachment of mouth bars follows three stages—channel bifurcation, accretion and coastal stabilization, and partial infilling—and a second phase involving the evolution of these channels on the delta plain through lateral migration, narrowing, and mouth closure. The complete cycle of mouth bar incorporation into the system is estimated to take approximately 30 years. The model suggests a general trend toward channel infilling, with localized erosional processes, with maximum rates of 0.5 m/year. These results contribute to understanding the key sedimentary processes that control deltaic dynamics in this section and provide a basis for guiding hydro-sedimentological research, redefining the shoreline, optimizing  dredging management, and improving wetland management in areas of high morphological dynamism.

Keywords: bifurcation, lateral migration, sinuosity, mouthbar