Flooding dynamics on the lower Amazon floodplain: 2. Seasonal and interannual hydrological variability

Autor(es)

Rudorff, Conrado M. ^[1] ; Melack, John M. ^[1] ; Bates, Paul D. ^[2]

Afiliação do(s) autor(es)

^[1] Univ Calif Santa Barbara, Bren Sch Environm Sci & Management, Santa Barbara, CA 93106 - USA

^[2] Univ Bristol, Sch Geog Sci, Bristol, Avon - England

• Tipo de documento: Artigo Científico
• Fonte: WATER RESOURCES RESEARCH; v. 50, n. 1, p. 635-649, JAN 2014.
• Citações Web of Science: 26

Resumo

We analyzed seasonal and interannual variability in hydrological fluxes and inundation dynamics of a large floodplain unit (2440 km(2)) along the lower Amazon River over a period of 15 years (1995-2010). Floodplain inundation was simulated using LISFLOOD-FP, which combines one-dimensional river routing with two-dimensional overland flow, and a local hydrological model. Dominant sources of inflow varied seasonally among direct rain and local runoff (November), Amazon River (December to August) and seepage (September and October). Shifts in timing of dominance among the water balance components occurred conform variations in annual peak stage. The period of dominance of river inflow over total floodplain influxes began about 1 month earlier and ended 1 month later in the 2009 high flood year compared to the 1998 low flood year. On average, river to floodplain discharge represented 0.75% of the Amazon River discharge at bidos and 82% of the annual hydrological influxes to the floodplain. We observed an up to ninefold variation in river-floodplain annual discharge. Relatively small increments in main stem peak discharge cause disproportionately large changes in the flow routed through the floodplain. Despite the higher frequency of years with lower minimum stages, the intensification of the hydrological cycle of the Amazon Basin is causing substantially greater amounts of riverine water to flow across floodplain environments. Key Points <list list-type={''}bulleted{''}> Floodplain hydrological fluxes were analyzed with an inundation model Proportion of water supplied from river and local sources varied seasonally Up to ninefold interannual variation in river-floodplain exchange was observed (AU)

• Processo FAPESP: 02/09911-1 - Monitoramento automático de variáveis limnológicas em sistemas aquáticos amazônicos sujeitos a diferentes graus de interferência antrópica
• Beneficiário: José Luiz Stech
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 03/06999-8 - Estudo da dinâmica de circulação da água entre sistemas lóticos, lênticos e a planície de inundação
• Beneficiário: Evlyn Márcia Leão de Moraes Novo
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 11/23594-8 - Sensoriamento remoto aplicado à modelagem de impactos antropogênicos sobre propriedades ecológicas de ambientes alagáveis e aquáticos da planície do Solimões/Amazonas
• Beneficiário: Evlyn Márcia Leão de Moraes Novo
• Modalidade de apoio: Auxílio à Pesquisa - Regular