Hydrologic variability and sediment supply of the Xingu and Tapajós rivers: Climate change and anthropogenic impacts in eastern Amazon rivers during Holocene

• Grant number: 16/11141-2
• Support type: Scholarships in Brazil - Doctorate
• Effective date (Start): January 01, 2017
• Effective date (End): September 30, 2019
• Field of knowledge: Physical Sciences and Mathematics - Geosciences - Geology
• Principal researcher: André Oliveira Sawakuchi
• Grantee: Dailson José Bertassoli Junior
• Home Institution: Instituto de Geociências (IGC). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 13/50180-5 - Xingu: integrating land use planning and water governance in Amazonia: towards improved freshwater security, AP.PFPMCG.TEM
• Associated scholarship(s): 17/25735-4 - Organic geochemistry analysis to reconstruct hydroclimate changes across eastern and western Amazon during the last 4,000 years, BE.EP.DR

Abstract

The Amazon Rainforest and the Amazon River System are unique ecosystemssupporting the world´s largest terrestrial and aquatic biodiversity. Those ecosystemsalso have an important role for the global climate system and precipitation distributionin South America. The Xingu and Tapajós Rivers are the largest clear water tributariesof the Amazon River. Both rivers stand out due to their specific biodiversity, uniquelandscape and as the main sources of surface water for agriculture and energygeneration in eastern Amazon. Due to their socioeconomic importance, the Xingu andTapajós basins are threatened by the increasing anthropogenic impacts associatedwith the planning or building of hydropower dams and expansion of agropastoralactivities. Future climate scenarios projected for eastern Amazon indicate increasingfrequency of severe droughts and reduction of water availability. Thus, thereconstruction of Holocene hydroclimate in the Xingu and Tapajós basins is a criticalissue to understand the response of clear water Amazon rivers to future climate andanthropogenic changes. Severe hydroclimate and vegetation changes can threatsurface water availability as well as promote shifts in sedimentation and carbon cycling,affecting ecosystems. This project will use sediment cores to reconstruct the Holocenehydroclimate in the Xingu and Tapajós watersheds through the application of proxiesbased on isotope analysis of organic specific-compounds, luminescence of mineralsand inorganic geochemistry (major elements). These proxies will allow reconstructingchanges in precipitation, vegetation and sediment supply. Age models will beconstrained by radiocarbon and luminescence ages. Changes in precipitation,vegetation and sediment supply will be compared to global climate events and changesin the South American Monsoon System recorded by other climate records. Changes inthe last century will be compared to deforestation rates in the Xingu and TapajósBasins.

Scientific publications

(4)

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

HAGGI, CHRISTOPH; SCHEFUSS, ENNO; SAWAKUCHI, ANDRE O.; CHIESSI, CRISTIANO M.; MULITZA, STEFAN; BERTASSOLI JR, DAILSON J.; HEFTER, JENS; ZABEL, MATTHIAS; BAKER, PAUL A.; SCHOUTEN, STEFAN. Modern and late Pleistocene particulate organic carbon transport by the Amazon River: Insights from long-chain alkyl diols. GEOCHIMICA ET COSMOCHIMICA ACTA, v. 262, p. 1-19, OCT 1 2019. Web of Science Citations: 0.

DE ARAUJO, KLEITON R.; SAWAKUCHI, HENRIQUE O.; BERTASSOLI, JR., DAILSON J.; SAWAKUCHI, ANDRE O.; DA SILVA, KARINA D.; VIEIRA, THIAGO B.; WARD, NICHOLAS D.; PEREIRA, TATIANA S. Carbon dioxide (CO2) concentrations and emission in the newly constructed Belo Monte hydropower complex in the Xingu River, Amazonia. BIOGEOSCIENCES, v. 16, n. 18, p. 3527-3542, SEP 18 2019. Web of Science Citations: 1.

BERTASSOLI, JR., D. J.; SAWAKUCHI, A. O.; CHIESSI, C. M.; SCHEFUSS, E.; HARTMANN, G. A.; HAEGGI, C.; CRUZ, F. W.; ZABEL, M.; MCGLUE, M. M.; SANTOS, R. A.; PUPIM, F. N. Spatiotemporal Variations of Riverine Discharge Within the Amazon Basin During the Late Holocene Coincide With Extratropical Temperature Anomalies. Geophysical Research Letters, v. 46, n. 15, p. 9013-9022, AUG 16 2019. Web of Science Citations: 0.

PUPIM, F. N.; SAWAKUCHI, A. O.; ALMEIDA, R. P.; RIBAS, C. C.; KERN, A. K.; HARTMANN, G. A.; CHIESSI, C. M.; TAMURA, L. N.; MINELI, T. D.; SAVIAN, J. F.; GROHMANN, C. H.; BERTASSOLI, JR., D. J.; STERN, A. G.; CRUZ, F. W.; CRACRAFT, J. Chronology of Terra Firme formation in Amazonian lowlands reveals a dynamic Quaternary landscape. QUATERNARY SCIENCE REVIEWS, v. 210, p. 154-163, APR 15 2019. Web of Science Citations: 3.