Proposal for the Characterization of Torrential Behavior of Colombian Andean Basins

The present work proposes the definition of geomorphological indicators that allow the identification of basins with higher susceptibility to torrential behavior within the Magdalena - Cauca hydrographic area (Colombia), area that is highly monitored (sediment measurement for more than 40 years) due to its great morphological and climatic diversity. This area has hydro-sedimentological modeling studies carried out by IDEAM (Instituto de Hidrología, Meteorología y estudios Ambientales), which have demonstrated the underestimation of sediment transport records during the occurrence of extreme events in small mountain basins.

The indicators will be found analyzing statistical patterns of the flow and sediment transport regime registered with the historical series. Additionally, watersheds are classified according to spatial scale and basin and channel geomorphology, with the aim of find which classification criterion explains underestimation. The error is calculated by downstream mass balance, where stations report less uncertain data. When the error by underestimation is higher than an acceptable threshold the basins are torrential and the current method of measurement must be reconsidered.