Modelling the climate change impacts on river discharge and inundation extent in the Magdalena River basin – Colombia

ABSTRACT

Climate change may have significant impacts on water balance and may considerably influence flooding dynamics of river systems by increasing extreme precipitation. This study evaluates the potential effects of climate change on river discharge and inundation in the Magdalena River basin, the main river in Colombia, using the synergy between the MGB (Modelo de Grandes Bacias) hydrological–hydrodynamic model and downscaled Eta-regional climate model (RCM) projections based on four global climate models (GCMs): BESM (Brazilian Earth System Model), CanESM2 (Canadian Earth System Model), MIROC5 (Model for Interdisciplinary Research on Climate Version Five), and HadGEM2-ES (Hadley Centre Global Environment Model version 2). We used two different greenhouse gas scenarios (RCP4.5 and RCP8.5 (Representative Concentration Pathway)) for the “historical” (1986–2005) and “mid-term prospective” (2046–2065) periods. Model results for the “mid-term prospective” period under scenarios RCP4.5 and RCP8.5 indicate increase in mean river discharges in the east portion of the basin, decreased river discharges (mainly in the dry season) in the upper Magdalena basin, and increased inundation extent. By coupling hydrological–hydrodynamic and GCMs/RCMs models, modelling frameworks like the one used in this study provide an effective management tool for stakeholders interested in potential climate change impacts on tropical river basins.

KEYWORDS:

• water resources
• flood hazard
• Colombia
• Mompós depression
• MGB model

Editor S. Archfield Associate Editor M. Batalini de Macedo

Editor S. Archfield Associate Editor M. Batalini de Macedo

Acknowledgements

The research was conducted thanks to the support of Ministerio de Ciencia Tecnología e Innovación Minciencias: Fondo Nacional de Financiamiento para la Ciencia, la Tecnología y la Innovación “Francisco José de Caldas” (Convocatoria 848 de 2019 Programa Estancias Postdoctorales) developed at the Corporación Centro de Desarrollo Tecnológico de las Pasifloras de Colombia - CEPASS. This study is derived from the Postdoctoral Research: “Potential impacts of climate change on the hydrological dynamics and the distribution patterns of Passion Fruit in the upper Magdalena River Basin, from hydrological modelling and species distribution modelling, using in-situ data, remote sensing techniques and CMIP5 projections”. The authors also acknowledge the Instituto Nacional de Pesquisas Espaciais (INPE: www.inpe.br) for freely providing the climate change projections used as input data to the model.

Disclosure statement

No potential conflict of interest was reported by the authors.