Author(s): Stevaux, Jose Cândido ; Macedo, Hudson de Azevedo ; Assine, Mario Luis [UNESP] ; Silva, Aguinaldo
Date: 2020
Persistent ID: http://hdl.handle.net/11449/201297
Origin: Oasisbr
Subject(s): Alluvial plain; Backwater flooding; Flood wave; Pantanal wetland; Wetland hydrology; Alluvial plain; Alluvial plain; Backwater flooding; Backwater flooding; Flood wave; Flood wave; Pantanal wetland; Pantanal wetland; Wetland hydrology; Wetland hydrology
Made available in DSpace on 2020-12-12T02:29:00Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-02-01
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
The channel-floodplain relationship is used to understand flooding dynamics in the Pantanal wetland. To understand how different fluvial styles along the Upper Paraguay River (UPR) control the hydrology of the Pantanal wetland, we used a database including 11 gauge stations from the Brazilian National Agency of Waters, Landsat series satellite data, GeoCover images circa 1990 and 2000, the SRTM 90 m digital elevation model (DEM) and 34 acoustic Doppler current profiler (ADCP) sections. We defined eight very distinct fluvial zones in the UPR within the Pantanal based on the channel-floodplain morphology, channel pattern, hydrologic function, and channel slope. Three zones are narrowing plains (Amolar, Urucum and Fecho dos Morros) constrained by geological features on the western border of the Pantanal sedimentary basin, which act as bottlenecks for flood runoff and produce backwater effects that delay flood wave transmission. In each of these narrow zones, the flood wave is delayed by flow velocity reduction, generating huge water bodies upstream that store flood water and affect the duration and amplitude of floods. The existence of three bottlenecks and the occurrence of a backwater effect constrain flood waves along the river, conditioning the hydrological regime of the entire wetland and resulting in unusual rating curves at some gauge stations along the UPR. This peculiar hydrological regime is responsible for the functioning of the wetland, including the undesirable “dequada” phenomena (natural fish mortality events). The backwater effect is enhanced by the existence of large flood basins upstream of the bottlenecks, where waters can be temporarily retained for periods of months, delaying the surface runoff and prolonging the flood season, which contributes to the maintenance of the wetland and its rich ecosystem.
Universidade Federal de Mato Grosso do Sul (UFMS) Avenida Ranulpho Marques Leal, 3484
Universidade Estadual de Maringá (UEM), Avenida Colombo 5790, Maringá
Universidade Estadual Paulista (UNESP), Avenida 24A 1515
Universidade Federal de Mato Grosso do Sul (UFMS), Avenida Rio Branco 1.270, Corumbá
Universidade Estadual Paulista (UNESP), Avenida 24A 1515
