Hidden in plain sight: How finding a lake in the Brazilian Pantanal improves understanding of wetland hydrogeomorphology

Autor(es)

Merino, Eder Renato ^[1] ; Assine, Mario Luis ^[2]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, NUPEGEL, Inst Energy & Environm, Av Prof Luciano Gualberto 1289, BR-05508010 Sao Paulo, SP - Brazil

^[2] Sao Paulo State Univ, UNESP, Inst Geosci & Exact Sci, Rio Claro - Brazil

• Tipo de documento: Artigo Científico
• Fonte: EARTH SURFACE PROCESSES AND LANDFORMS; v. 45, n. 2 DEC 2019.
• Citações Web of Science: 0

Resumo

Wetlands are permanently or seasonally flooded areas which support countless species of plants and animals. The Pantanal, in central-west Brazil is one of the largest freshwater wetlands in the world covering an area of similar to 150 000 km(2). The relationships between geomorphology, hydrology, sedimentation, and vegetation cover are critical for understanding how the landscape constrains the dynamics of wetlands. We provide a detailed study of the geomorphology and surface hydrology of the Negro River Interfan System (NRIS), in the southern Pantanal, by applying multiple approaches (i.e. remote sensing analysis, geomorphological zonation and hydrosedimentological surveys). A multitemporal analysis of Landsat imagery produced an inundation frequency map (2000-2011 period) that revealed a permanently flooded area in the central portion of the NRIS. A hidden fluvial lake was previously undetected due to the accumulation of floating mats and floating meadows of macrophytes. The Negro and Aquidauana feeder rivers exhibit remarkable differences in channel planform, water discharge, and sediment load. The Negro River presents a distributary pattern with marginal levees with decreasing elevation as it progrades into the lake and remains as a subaqueous landform conditioning the water flow downstream. The lake outflow to the Paraguay River occurs mainly by sheet flow during flood seasons and through small tributary channels during dry months. The lake's geometry is outlined by east-northeast and west-northwest straight borders, suggesting that the area is tectonically controlled. A cloud-based worldwide water surface database (1984-2015) revealed frequent channel changes within the NRIS. Recent channel avulsions in the lower course of the Negro River are noteworthy mainly because the former river channel at the confluence with the Paraguay River is no longer connected with the Negro River channel. (c) 2019 John Wiley \& Sons, Ltd. (AU)

• Processo FAPESP: 17/26318-8 - Mapeamento das lagoas salinas e cristalinas do Pantanal de Nhecolândia por meio de sensoriamento remoto ótico e interferométrico
• Beneficiário: Eder Renato Merino
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 16/14227-5 - Mudanças climáticas e impactos ambientais em áreas alagadas (wetlands) do Pantanal (Brasil): quantificação, fatores de controle e previsão em longo prazo
• Beneficiário: Adolpho José Melfi
• Modalidade de apoio: Auxílio à Pesquisa - Programa de Pesquisa sobre Mudanças Climáticas Globais - Temático
• Processo FAPESP: 14/06889-2 - Mudanças paleo-hidrológicas, cronologia de eventos e dinâmica sedimentar no quaternário da Bacia do Pantanal
• Beneficiário: Mario Luis Assine
• Modalidade de apoio: Auxílio à Pesquisa - Programa de Pesquisa sobre Mudanças Climáticas Globais - Regular