Simulação hidrológica em uma bacia hidrográfica andina sob cenários de mudanças climáticas

• Ano de defesa: 2013
• Autor(a) principal: Fernando Mauricio Castro Barrios
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; UFMG
• Palavras-chave em Português: SANEAMENTO MEIO AMB RECURSOS HÍDRICOS; Saneamento
• Link de acesso: http://hdl.handle.net/1843/BUBD-A7LJJ8

Among the great challenges of water management for the twenty-first century, the impacts of climate changes are issues that certainly affect directly human life because two of their most known effects: the lack and the excess of water. The objective of this research is to evaluate the potential effects of climate change on hydrology in a watershed by combining hydrological models and scenarios of greenhouse gases arising from the disposal of general circulation models (GCM) and regional circulation models (RCM); besides detailing the proceedings or chains of these models, the component of innovation is the implementation of this set of systems modeling for an Andean mountain watershed. Rainfall and streamflow simulations were developed for present and future climates for the period from 1988 to 2007 and from 2011 to 2030 with the global atmospheric model HadCM3-Scenario A1B proposed by the Intergovernmental Panel on Climate Change (IPCC). The simulation results served as boundary conditions for the regional circulation model PRECIS (Providing Regional Climates for Impact Studies) with 19 vertical levels and 25 km horizontal resolution; the numerical weather forecasts resulting from the nesting of regional circulation model (PRECIS) in a general circulation model of the atmosphere (HadCM3-A1B) were used to predict flows in an Andean basin. The Coello River basin, chosen as a case study, is located in the eastern slope of central Andes, at the Tolima Department, Colombia, with a drainage area of 1,817 km2. In order to correct the systematic errors in the precipitation forecasts, it was applied a transformation of the rainfall probability distribution curve, which has the advantage of handling inter-annual variability; the corrected rainfall was used as input to run the distributed hydrological model SWAT (Soil and Water Assessment Tool). Regarding the current period, the following scenarios forecasts in the Coello River basin for the 2011-2030 period were obtained: reduction of 3.5% of the average annual flow, reduction of 1.6% and 3.8% of the Q10 and Q90 values, respectively, from the flow-duration curve; increase of 4.0% in actual evapotranspiration. The proposed methodological approach is promising for the analysis of potential impacts of climate change on water resources in Colombian river basins located in the Andean regions. Given the uncertainties of the methodology, due to simplifications and limitations of the mathematical models used, the results should be used with caution. In any case, there is a concern with the finding that the estimated values of monthly average flow in the Coello River basin for the 2011-2030 period were lower than those observed in the 1988-2007 one.