Introduction:

Although Colombia has been recognized as a country of high biodiversity, it has limited studies about the interaction of biological variables with water bodies hydrodynamics of strategic ecosystems such as mountain rivers. Mathematical modeling has been widely used worldwide in order to understand rivers auto-purification dynamics.

Objective:

Formulate a mathematical model that couples biological and hydraulic variables to assess self-purification capacity of mountain rivers.

Materials and Methods:

An eco-hydraulic model is formulated based on the leaf litter retention and conservative dye tracer techniques. The formulation is validated using field measurements in a mountain river. It is presumed that the travel time estimated by the conservative dye tracer method can be used for the litter retention.

Results:

An eco-hydraulic formulation is obtained that would allow to know the hydrodynamics of the water body through variables such as flow, flow velocity and travel time in order to evaluate the river capacity to retain and degrade organic matter by action microorganisms (auto-purification).

Conclusion.

The integration of the experimental hydraulic travel time to a biological retentivity model makes possible to comprehensively evaluate the real auto-purification dynamics of a mountain river given for specific spatial and temporal hydrodynamic conditions.