TITLE:
Hydrological Processes and Climate Change in Hydrographic Regions of Brazil
AUTHORS:
Alfredo Ribeiro Neto, Adriano Rolim da Paz, José Antonio Marengo, Sin Chan Chou
KEYWORDS:
Hydrological Modelling, IPCC Scenarios, Climate Change, Impacts
JOURNAL NAME:
Journal of Water Resource and Protection,
Vol.8 No.12,
November
7,
2016
ABSTRACT: The
objective of this work is to assess the impacts of IPCC AR5 climate change
scenarios on water resources and hydrological processes across the entire
Brazilian territory. Hydrological simulations are carried out in total drainage
area of about 11,535,645 km2 and average stream flow of about
272,460 m3/s. The study area consists of different climates and land
covers such as the Amazon Forest, Northeast Semiarid, Brazilian Savannah,
Pantanal wetlands and temperate climate in the South. The atmospheric forcing
to drive the large-scale hydrological model MGB-IPH is derived from the
downscaling of two global climate models, HadGEM2-ES and MIROC5, by the Eta
Regional Climate Model, at 20 km resolution. The Eta model provided the
downscaling of the baseline (1961-1990) and three time-slices (2011-2040,
2041-2070 and 2071-2099). These projections adopted two emission scenarios, the
RCP 4.5 and RCP 8.5. The change in the average and extremes of precipitation,
evapotranspiration, rates of river discharge and soil moisture were assessed.
The simulations showed the response of the hydrographic regions due to change
of precipitation and potential evapotranspiration in the scenarios. Water
availability decreases in almost the entire study area (exception for the
South) and the major basins for hydroelectric power generation are affected.
The Northwest, Amazon and a small area along the Northeast Atlantic coast
exhibited intensification of the extremes discharges, where the anomaly is
positive for high-flow (Q10)
and negative for low-flow (Q95).
The results highlight the most climatic sensitive regions in Brazil in terms of
hydrological variables and water resources.