Evaluación de la Metodología Ifim-Phabsim para la Determinación de Caudales Ambientales en un Tramo de la Subcuenca Río Neusa

Abstract

Ecological water flow is a determining factor in the conservation of the species that inhabit a water body. However, intervention of human activities affects the natural conditions of the watercourses and thus the ability of the species that shelter those waters to survive. In this project the simulation of the physical habitat of a 12,5 m long section at the southwestern outlet of the Neusa dam, in order to determine the Weighted Usable Area (WUA) and with these the ecological water flow required for the survival of the species Eremophilus mutisii (Capitán de la Sabana) endemic of the Colombian high mountain ecosystem, in its young and adult life stages. For this, the IFIM methodology and the software PHABSIM (Physical Habitat Simulation System) was used. In this system, the WUA modeling is done keeping in mind the hydrometric variables of the section or channel under study and habitat preference curves for the target species; having as a result the WUA relations with the section flows. In the generated graphs, it was possible to determine that the necessary flow for the conservation of the young community is between 0,2 and 0,5 m3/s and for the adult stage it is between 0,5 and 1,2 m3/s. Flows above or below these values cause alterations on the community and can lead to the decrease of individuals of this species. This project made it possible to determine the possibility of using this methodology for the determination of ecological water flows and thus a flow regime associated with the characteristics of an objective species.