Eliana Bohórquez Bedoya

• Tropical reservoirs are recognized as globally important sources of greenhouse gases (GHG). Tropical mountainous areas of high hydroelectric development have been poorly studied. The objective of this study is to understand GHG dynamics in tropical mountain reservoirs. Data on seasonal and diurnal GHG dynamics were collected during six field campaigns in the Porce III reservoir in the Colombian Andes, where the importance of oxic CH4 production in the variability of dissolved gas at the surface, as well as the variation of water levels as an incident factor in GHG fluxes on a seasonal scale, was evidenced. CO2 flux at the reservoir water-atmosphere interface were monitored with a high-resolution technique over periods of several weeks, where the importance of primary productivity in the diurnal cycling of CO2 flux was inferred, showing alternation as sink-source, and pulses of synoptic-scale CO2 flux were observed as a consequence of the simultaneous occurrence of increases in surface concentrations and high wind speed. In laboratory experiments, a relationship was found between rain rate, turbulent kinetic energy dissipation rate and gas transfer rate, contributing to the modeling of this phenomenon with applicability in inland waters. In general, the results obtained contribute to the understanding of GHG dynamics in eutrophic tropical reservoirs.