WATER BALANCE BASED ON REMOTE SENSING DATA IN PANTANAL/BALANCO HIDRICO NO PANTANAL USANDO DADOS DE SENSORIAMENTO REMOTO

• Published in: Ra'e ga Vol. 46; no. 3; p. 20
• Main Authors: Moreira, Adriana Aparecida, Fassoni-Andrade, Alice Cesar, Ruhoff, Anderson Luis, Cauduro, Rodrigo, de Paiva, Dias
• Format: Journal Article
• Language: Spanish
• Published: Editora da UFPR 01.09.2019
• Subjects: Analysis; Remote sensing; Water balance (Hydrology); Wetlands
• ISSN: 1516-4136
• DOI: 10.5380/raega

Pantanal, located in the Upper Paraguay basin, is the world's largest tropical wetland. The maintenance of this ecosystem depends on the water balance since precipitation is seasonal and high losses of water occur due to the high evapotranspiration. Water balance assessment using in situ data is still a challenge due to the large extension of the area and the complexity to be represented. In this study, the water balance in the Upper Paraguay basin was investigated based on hydrological variables derived from remote sensing data. Precipitation, evapotranspiration, and water storage change data were estimated with accuracy by the water balance, but the same was not possible for the discharge. However, high uncertainties in the estimates were verified, mainly during the rainy season. The remote sensing data allowed the identification of the seasonality of hydrological variables in the Pantanal system and in the different regions of the basin: Chaco, Pantanal and Planalto. Water deficit in the basin was observed from March/April to September as well as a positive water balance due to precipitation during the rest of the year. The spatial analysis of the basin showed that in the northern region, the precipitation, the evapotranspiration, and the water storage variation are higher than in the southern region. Results demonstrated that remote sensing data can help in the comprehension of hydrological systems operation, especially in large wetland regions. Keywords: Evapotranspiration; GRACE; Wetlands; Water regime. O Pantanal, localizado na bacia do Alto Paraguai, e a maior area de wetlands do mundo. A manutencao desse ecossistema depende do balanco hfdrico uma vez que a precipitacao e sazonal e altas perdas de agua ocorrem devido as elevadas taxas de evapotranspiracao. Analisar o balanco hfdrico utilizando dados in situ ainda e um desafio devido a grande extensao da area e toda sua complexidade a ser representada. Neste estudo o balanco hfdrico na bacia do Alto Paraguai foi investigado utilizando variaveis hidrologicas baseadas em sensoriamento remoto. Dados de precipitacao, evapotranspiracao e variacao do armazenamento da agua foram estimados com boa acuracia pelo balanco hfdrico, entretanto, o mesmo nao foi possfvel para a estimativa da vazao. Altas incertezas nas estimativas foram verificadas, principalmente durante o perfodo chuvoso. Estimativas de sensoriamento remoto demonstram a sazonalidade das variaveis hidrologicas no sistema Pantanal e nas diferentes regioes da bacia: Chaco, Pantanal e Planalto. Foi observado deficit de agua na bacia de marco/abril ate setembro e um saldo positivo nos meses restantes do ano devido a precipitacao. A analise espacial da bacia mostrou que na regiao norte a precipitacao, a evapotranspiracao e a variacao do armazenamento da agua sao maiores que na regiao sul. Os resultados deste estudo demonstraram que os dados de sensoriamento remoto podem ajudar na compreensao do funcionamento de sistemas hidrologicos, principalmente em regioes de grandes areas umidas. Palavras chave: Evapotranspiracao; GRACE; Areas umidas; Regime hfdrico.