Location: Southwest Watershed Research CenterTitle: Trends in water balance components across the Brazilian Cerrado
|SANCHES OLIVEIRA, P. - Universidad De Sao Paulo|
|Goodrich, David - Dave|
|WENDLAND, E. - Universidad De Sao Paulo|
|GUPTA, H.V. - University Of Arizona|
Submitted to: Water Resources Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/15/2014
Publication Date: 12/1/2014
Citation: Sanches Oliveira, P., Nearing, M.A., Moran, M.S., Goodrich, D.C., Wendland, E., Gupta, H. 2014. Trends in water balance components across the Brazilian Cerrado. Water Resources Research. 50:7100-7114. https://doi.org/10.1002/2013WR015202.
Interpretive Summary: The tropical forests, savannas, biological diversity and freshwater resources of Brazil are among the world’s largest. The Brazilian Cerrado is considered one of the most important Brazilian biomes, covering an area of 2 million km2 (~22% of the total area of Brazil) and is the second largest biome in South America. The physiognomies of the Cerrado vary from grassland to savanna to forest. Because of its endemic plant and vertebrate species, this biome has been classified as one of the 25 global biodiversity hotspots. Despite the importance of the Brazilian Cerrado, knowledge of the water balance dynamics associated with the change from native cover to grassland and cropland is still limited. In this study, we review the available literature on the components of the water balance in the Brazilian Cerrado to obtain a better understanding of the consequences of deforestation for the water balance in the Cerrado. Results indicated that deforestation and streamflow, erosion processes and sediment yield have tended to increase. We detected no statistically significant decrease in the overall annual average evapotranspiration in the Cerrado biome in the 2000 to 2010 period, but we did detect significant decreases in some states with rapid deforestation.
Technical Abstract: The Brazilian Cerrado (Savanna) is considered one of the most important biomes for Brazilian water resources; however, little is known about the components of the water balance in this biome. In this study, we reviewed the available literature on the water balance components in the Brazilian Cerrado to obtain a better understanding of the consequences of deforestation for the water balance in the Cerrado. We reviewed papers published through 2012, and we used TRMM and MOD16 data for the period from 2000 to 2010 to evaluate the water balance dynamics of the Cerrado. We found several gaps in the information available about various components of water balance in the Cerrado, including interception, runoff, infiltration, percolation, shallow throughflow and groundwater recharge. Although there was no statistically significant decrease in the overall annual average evapotranspiration (~2% or 24.57 km3 yr-1) in the Cerrado biome between 2000 and 2010 period, we detected significant decreases in some states with high deforestation index values, such as Maranhão-MA(~4% or 10.80 km3 yr-1), Piauí-PI (~9% or 9.15 km3 yr-1) and Bahia-BA (~10% or 13.05 km3 yr-1). These states accounted for ~36% of the deforestation in the Cerrado during the study period. We can infer that deforestation in the Cerrado has reduced annual evapotranspiration (ET) and may contribute to increased streamflow. The findings of this study can be used to develop new research studies to fill in the information gaps that exist and address the challenges that have been identified concerning the water balance in the Cerrado.