336 results on '"Collischonn, Walter"'
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152. Simulação Hidrológica de Rios com Grandes Planícies de Inundação
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Paz, Adriano, primary, Collischonn, Walter, additional, and TUCCI, CARLOS, additional
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- 2010
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153. DESEMPENHO DO SATÉLITE TRMM NA ESTIMATIVA DE PRECIPITAÇÃO SOBRE A BACIA DO PARAGUAI SUPERIOR
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Collischonn, Bruno, primary, Allasia, Daniel, additional, Collischonn, Walter, additional, and Tucci, Carlos Eduardo Morelli, additional
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- 2009
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154. Verificação da Eficiência e Eficácia de um Algoritmo Evolucionário Multi-objetivo na Calibração Automática do Modelo Hidrológico IPH II
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TUCCI, CARLOS, primary, Bravo, Juan, additional, and Collischonn, Walter, additional
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- 2009
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155. Comparação de Métodos para Definir Direções de Escoamento a partir de Modelos Digitais de Elevação
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Paz, Adriano, primary, Collischonn, Walter, additional, and FAN, FERNANDO, additional
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- 2009
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156. Análise Multivariada do Processo de Evapotranspiração em Áreas de Cerrado e Cana-de-Açúcar
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RUHOFF, ANDERSON, primary, Saldanha, Claudineia, additional, Collischonn, Walter, additional, Uvo, Cintia, additional, Rocha, Humberto, additional, and CABRAL, OSVALDO, additional
- Published
- 2009
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157. Modelling spatial heterogeneity of phytoplankton in Lake Mangueira, a large shallow subtropical lake in South Brazil
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Fragoso, Carlos R., primary, Marques, David M.L. Motta, additional, Collischonn, Walter, additional, Tucci, Carlos E.M., additional, and van Nes, Egbert H., additional
- Published
- 2008
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158. AVALIAÇÃO DO DESEMPENHO DE UM ALGORITMO BASEADO NO COMPORTAMENTO DE FORMIGAS EM PROBLEMAS DE CAMINHO DE MÍNIMO CUSTO EM AMBIENTES RASTER
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Bravo, Juan Martín, primary, Collischonn, Walter, additional, Pilar, Jorge Víctor, additional, and Gonçalves, Alexandre, additional
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- 2008
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159. Short‐ and long‐term flow forecasting in the Rio Grande watershed (Brazil)
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Tucci, Carlos E. M., primary, Collischonn, Walter, additional, Clarke, Robin T., additional, Paz, Adriano R., additional, and Allasia, Daniel, additional
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- 2008
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160. Otimização de Regras de Operação de Reservatórios com Incorporação da Previsão de Vazão
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TUCCI, CARLOS, primary, PILAR, JORGE, additional, Bravo, Juan, additional, and Collischonn, Walter, additional
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- 2008
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161. Ecohydrology towards the sustainable development: An approach based on South American case studies
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Freire Souza, Christopher, primary, Tassi, Rutinéia, additional, Motta Marques, David da, additional, Collischonn, Walter, additional, and Antonio Agostinho, Angelo, additional
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- 2008
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162. Simulação da Qualidade de Água em Grandes Bacias: Rio Taquari-Antas, RS
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TUCCI, CARLOS, primary, Collischonn, Walter, additional, and LARENTIS, DANTE, additional
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- 2008
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163. Avaliação dos Benefícios de Previsões de Vazão na Operação de Reservatórios
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Silva, Benedito, primary, PILAR, JORGE, additional, TUCCI, CARLOS, additional, Bravo, Juan, additional, and Collischonn, Walter, additional
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- 2008
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164. Simulação na Bacia Amazônica com Dados Limitados: Rio Madeira
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NETO, ALFREDO, primary, TUCCI, CARLOS, additional, SILVA, RUI, additional, and Collischonn, Walter, additional
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- 2008
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165. The MGB-IPH model for large-scale rainfall—runoff modelling
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COLLISCHONN, WALTER, primary, ALLASIA, DANIEL, additional, DA SILVA, BENEDITO C., additional, and TUCCI, CARLOS E. M., additional
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- 2007
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166. Modelo Hidrológico Distribuído para Previsão de Vazões Incrementais na Bacia do Rio Paranaíba entre Itumbiara e São Simão
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Paz, Adriano, primary, Silva, Benedito, additional, COLLISCHONN, BRUNO, additional, TUCCI, CARLOS, additional, Piccilli, Daniel, additional, CORBO, MARTIN, additional, CLARKE, ROBIN, additional, and Collischonn, Walter, additional
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- 2007
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167. Simulação de Eutrofização em Lagos Rasos II: Sistema do Taim (RS)
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TUCCI, CARLOS, primary, Marques, David, additional, Collischonn, Walter, additional, and Júnior, Carlos, additional
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- 2007
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168. Simulação de Eutrofização em Lagos Rasos: I - Modelo e Precisão Numérica
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TUCCI, CARLOS, primary, Júnior, Carlos, additional, Marques, David, additional, and Collischonn, Walter, additional
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- 2007
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169. Previsão Hidroclimática de Vazão de Curto Prazo na Bacia do Rio São Francisco
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Silva, Benedito, primary, TUCCI, CARLOS, additional, CLARKE, ROBIN, additional, Collischonn, Walter, additional, and CORBO, MARTIN, additional
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- 2007
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170. Improvements in large-scale drainage networks derived from digital elevation models
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Paz, Adriano Rolim, primary, Collischonn, Walter, additional, and Lopes da Silveira, André Luiz, additional
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- 2006
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171. Análise da Rede de Postos de Chuva na Previsão em Tempo Real na Bacia do Rio Uruguai
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TUCCI, CARLOS, primary, ANDREOLLI, IVANILTO, additional, and Collischonn, Walter, additional
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- 2006
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172. Previsão de Vazão Afluente a um Reservatório Utilizando Previsão Quantitativa de Chuva
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TUCCI, CARLOS, primary, ANDREOLLI, IVANILTO, additional, REGINA, JOSE, additional, HAAS, REINALDO, additional, and Collischonn, Walter, additional
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- 2006
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173. Previsão de Vazão com Modelos Hidroclimáticos
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Silva, Benedito, primary, TUCCI, CARLOS, additional, and Collischonn, Walter, additional
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- 2006
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174. Previsão Sazonal de Vazão na Bacia do Rio Uruguai 1: Ajuste e Verificação do Modelo Hidrológico Distribuído
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TUCCI, CARLOS, primary and Collischonn, Walter, additional
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- 2005
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175. Previsão Sazonal de Vazão na Bacia do Rio Uruguai 2: Previsão Climática-Hidrológica
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TUCCI, CARLOS, primary, OLIVEIRA, GILVAN, additional, DIAS, PEDRO, additional, CLARKE, ROBIN, additional, and Collischonn, Walter, additional
- Published
- 2005
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176. Long‐term flow forecasts based on climate and hydrologic modeling: Uruguay River basin
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Tucci, Carlos Eduardo Morelli, primary, Clarke, Robin Thomas, additional, Collischonn, Walter, additional, da Silva Dias, Pedro Leite, additional, and de Oliveira, Gilvan Sampaio, additional
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- 2003
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177. Ajuste Multiobjetivo dos Parâmetros de um Modelo Hidrológico
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TUCCI, CARLOS, primary and Collischonn, Walter, additional
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- 2003
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178. Variabilidade Temporal no Regime Hidrológico da Bacia do Rio Paraguai
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TUCCI, CARLOS, primary, CLARKE, ROBIN, additional, and Collischonn, Walter, additional
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- 2003
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179. Simulação Hidrológica de grandes Bacias
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TUCCI, CARLOS, primary and Collischonn, Walter, additional
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- 2001
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180. Simulação Numérica de Canais de Irrigação controlados por comportas automáticas
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MEIRELLES, FERNANDO, primary, ENDRES, LUIZ, additional, and Collischonn, Walter, additional
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- 2001
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181. A direction dependent least-cost-path algorithm for roads and canals
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Collischonn, Walter, primary and Pilar, Jorge Victor, additional
- Published
- 2000
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182. The influence of vertical water balance on modelling Pantanal (Brazil) spatio-temporal inundation dynamics.
- Author
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Paz, Adriano Rolim, Collischonn, Walter, Bravo, Juan Martín, Bates, Paul D., and Baugh, Calum
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WATER ,SPATIO-temporal variation ,FLOODS ,EVAPOTRANSPIRATION - Abstract
The current benchmark approach for mathematical modelling of floodplain hydrologic regime consists of dynamically coupling one-dimensional (1D) and two-dimensional (2D) models for flow routing along the main channel and the floodplain, respectively. For large-scale sites, floodplain inundation may spread over hundreds of square kilometres and may last for many months and even influence seasonal floods in following years. This paper aims at evaluating the effect of vertical water balance representation on modelling a large-scale floodplain. The Pantanal wetland (140 000 km
2 ; Brazil) is simulated using a 1D/2D coupled model approach, which also considers the representation of vertical water processes over the floodplain. Four scenarios are simulated: Baseline (the reference scenario), NoVertBal (in which the vertical water balance over floodplain is turned off) and ETp+1 and ETp−1 scenarios, characterized by artificially increasing or decreasing daily potential evapotranspiration (ETp) by 1 mm, respectively. The results showed that the effect of the vertical water processes scenarios on channel flow is directly dependent on the lateral exchange of water between the channel and floodplain in the upstream river reach. This influence is stronger when there is a gain of water from the floodplain to the channel. The inclusion of these vertical water processes into floodplain modelling was essential to represent the process of wetting and drying, this effect being more relevant for areas not directly connected to main channels, which is a characteristic of the Pantanal region. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]- Published
- 2014
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183. Análise do rompimento hipotético da barragem de Ernestina
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TUCCI, CARLOS, primary and Collischonn, Walter, additional
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- 1997
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184. Defining parameters for Eckhardt's digital baseflow filter.
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Collischonn, Walter and Fan, Fernando Mainardi
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DIGITAL electric filters ,GROUNDWATER ,STREAMFLOW ,PARAMETERS (Statistics) ,WATERSHEDS - Abstract
Digital filters are useful tools for assessing the contribution of groundwater to total river flow. Several of those filters have been proposed in the last decades. One of the last contributions on this subject was given by Ekchardt (2005) who proposed a more general form of a digital baseflow filter and showed that some of the most used filters are special cases of this general form. This new filter has the inconvenience of having two parameters, one of them may be obtained directly from recession analysis, but the other (maximum baseflow index (BFImax)) is routinely estimated by a priori defined values according to the predominant geological characteristics of the drainage basin. In this short communication, we propose a method to estimate BFImax by a backwards filtering operation. The method was applied using data from 15 gauging stations in Brazil, with a varied range of groundwater contribution to streamflow. Results of the new estimation method for the BFImax parameter are coherent with the values which would be adopted by considering geological characteristics of the river basins. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]
- Published
- 2013
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185. Validation of a full hydrodynamic model for large-scale hydrologic modelling in the Amazon.
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Paiva, Rodrigo C. D., Collischonn, Walter, and Buarque, Diogo Costa
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HYDRODYNAMICS ,FLUID dynamics ,WATERSHEDS ,LANDFORMS - Abstract
A key aspect of large river basins partially neglected in large-scale hydrological models is river hydrodynamics. Large-scale hydrologic models normally simulate river hydrodynamics using simplified models that do not represent aspects such as backwater effects and flood inundation, key factors for some of the largest rivers of the world, such as the Amazon. In a previous paper, we have described a large-scale hydrodynamic approach resultant from an improvement of the MGB-IPH hydrological model. It uses full Saint Venant equations, a simple storage model for flood inundation and GIS-based algorithms to extract model parameters from digital elevation models. In the present paper, we evaluate this model in the Solimões River basin. Discharge results were validated using 18 stream gauges showing that the model is accurate. It represents the large delay and attenuation of flood waves in the Solimões basin, while simplified models, represented here by Muskingum Cunge, provide hydrographs are wrongly noisy and in advance. Validation against 35 stream gauges shows that the model is able to simulate observed water levels with accuracy, representing their amplitude of variation and timing. The model performs better in large rivers, and errors concentrate in small rivers possibly due to uncertainty in river geometry. The validation of flood extent results using remote sensing estimates also shows that the model accuracy is comparable to other flood inundation modelling studies. Results show that (i) river-floodplain water exchange and storage, and (ii) backwater effects play an important role for the Amazon River basin hydrodynamics. Copyright © 2011 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]
- Published
- 2013
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186. Large-scale modelling of channel flow and floodplain inundation dynamics and its application to the Pantanal (Brazil).
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Paz, Adriano Rolim da, Collischonn, Walter, Tucci, Carlos E. M., and Padovani, Carlos R.
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FLOODPLAIN management ,WETLAND co-management ,FLOOD control channels ,SIMULATION methods & models - Abstract
For large-scale sites, difficulties for applying coupled one-dimensional (1D)/2D models for simulating floodplain inundation may be encountered related to data scarcity, complexity for establishing channel-floodplain connections, computational cost, long duration of floods and the need to represent precipitation and evapotranspiration processes. This paper presents a hydrologic simulation system, named SIRIPLAN, developed to accomplish this aim. This system is composed by a 1D hydrodynamic model coupled to a 2D raster-based model, and by two modules to compute the vertical water balance over floodplain and the water exchanges between channel and floodplain. Results are presented for the Upper Paraguay River Basin (UPRB), including the Pantanal, one of the world's largest wetlands. A total of 3965 km of river channels and 140 000 km of floodplains are simulated for a period of 11 years. Comparison of observed and calculated hydrographs at 15 gauging stations showed that the model was capable to simulate distinct, complex flow regimes along main channels, including channel-floodplain interactions. The proposed system was also able to reproduce the Pantanal seasonal flood pulse, with estimated inundated areas ranging from 35 000 km (dry period) to more than 120 000 km (wet period). Floodplain inundation maps obtained with SIRIPLAN were consistent with previous knowledge of Pantanal dynamics, but comparison with inundation extent provided by a previous satellite-based study indicates that permanently flooded areas may have been underestimated. The results obtained are promising, and further work will focus on improving vertical processes representation over floodplains and analysing model sensitivity to floodplain parameters, time step and precipitation estimates uncertainty. Copyright © 2010 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]
- Published
- 2011
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187. Development of a Flood Forecasting System for the State of Rio Grande do Sul, Brazil.
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Fan, Fernando Mainardi, Fleischmann, Ayan dos Santos, Siqueira, Vinicius Alencar, Nectoux, Marcela, Giacomelli, Lucas, and Collischonn, Walter
- Published
- 2019
188. Improving reliability and skill of medium-range hydrological ensemble forecasts over South America using EMOS.
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Siqueira, Vinícius, Weerts, Albrecht, Verkade, Jan, Klein, Bastian, Fan, Fernando, Paiva, Rodrigo, and Collischonn, Walter
- Published
- 2019
189. Hydrological Reanalysis Across the 20th Century: A Case Study of the Amazon Basin.
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Wongchuig, Sly, Paiva, Rodrigo, Siqueira, Vinícius, and Collischonn, Walter
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- 2019
190. Hydrological reanalysis across the 20th century: A case study of the Amazon Basin.
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Wongchuig, Sly Correa, de Paiva, Rodrigo Cauduro Dias, Siqueira, Vinícius, and Collischonn, Walter
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HYDROLOGIC models , *HYDROLOGY , *WATER supply , *WATER levels - Abstract
Highlights • Hydrological Reanalysis HR is proposed using hydrologic model and data assimilation of in-situ observations. • Unbiased large dataset of climate reanalysis is used as forcing for the hydrologic model. • Local data assimilation technique is used to improve hydrologic spatio-temporal fields. • HR is used in the Amazon to validate and study their hydrology along the 20th century. Abstract Adequate and accurate hydrological data is necessary to manage water resources, which are critical in developing countries where such information is limited. In recent years, global reanalysis datasets have been developed to provide this information in climatic fields and, more recently, in hydrologic fields. Nevertheless, these latest efforts have been limited to temporal coverage (∼30 years) and mostly simplified hydraulic scheme routing in rivers, which can be inadequate for regional and long term scale objectives. In this article, a dataset (called hydrological reanalysis across the 20th century [HRXX] in the Amazon Basin) was developed as a case study spanning back to the year 1900 through the use of: 1) a large-scale hydrologic-hydrodynamic model (MGB) forced by a long-term climatic reanalysis of rainfall (ERA-20CM) with bias removed; and 2) a data assimilation (DA) technique coupled with a localization method (LEnKF) to use several ground observations of daily discharge within a radius of influence. Several tests were assessed to find the best bias removal method, the optimal radius of influence for the localization method and the final HRXX dataset. A total of 114 hydrological ground observations of daily information were used for assimilation and validation purposes, and several statistics indexes were employed to assess their performance. Results indicate that both bias correction and the DA with localization method greatly improved the simulations. Overestimations of the peaks in the open-loop (OL) (free run) simulation, mainly in the southern and northern regions of the Amazon Basin, were removed, and recession timing in the east-central region, as seen at the Óbidos gauge station, were corrected. An average performance of ∼0.6 and ∼0.7 of the Nash–Sutcliffe and Kling–Gupta indexes was reached, even when only a few of the longest ground observations were used, which can be representative of the oldest periods (since ∼1930). To assess extreme events, the Pearson correlation coefficient was used for maximum and minimum annual water level anomaly values, reaching 0.6 and 0.7, respectively, at the Manaus gauge station, which is remarkable considering that the analysis covers approximately 110 years. Considering the results of this case study and the global coverage of rainfall datasets, this methodology can be transferred to other regions in order to better estimate and create a hydrological reanalysis that adequately represents the hydrologic and hydraulic spatio-temporal fields. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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191. A first integrated modelling of a river-lagoon large-scale hydrological system for forecasting purposes.
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Lopes, Vitória Ache Rocha, Fan, Fernando Mainardi, Pontes, Paulo Rógenes Monteiro, Siqueira, Vinicius Alencar, Collischonn, Walter, and Motta Marques, David da
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HYDROLOGY , *HYDRODYNAMICS , *LAGOONS , *RIVERS , *HYDRAULIC models - Abstract
Highlights • First single hydrologic-hydrodynamic modeling of an integrated river-lagoon system. • Approach for large-scale river-lagoon forecasting systems of discharges and levels. • Implementation of wind shear effects on local inertial one-dimensional equations. • Sensitivity testing of wind shear coefficients, input wind data and tide effects. • First known complete Patos Lagoon watershed system modelling study. Abstract Hydrological-hydrodynamic modelling of basins, rivers and large bodies of water, such as lakes and lagoons, is usually performed by external coupling of hydrological-hydraulic models and 2D or 3D hydrodynamic models. Therefore, the river discharges into the lake are calculated by using the hydrologic model. The data is used then as an input to the hydrodynamic model. This approach allows for a detailed simulation of lake or lagoon hydrodynamics and circulation. However, when the objective is solely to simulate water levels and flooded areas, this approach may become too costly, making it difficult to establish operational systems such as those for flood forecasting. Therefore, in the present study, we propose a first integrated approach using one single hydrologic-hydraulic model, the MGB-IPH model, to simulate complex systems such as wind shear influence. This model was applied to simulate the Patos Lagoon (PL) basin located in Brazil and Uruguay countries. Results showed that it was possible to use the single model to simulate hydrographs, flooded areas and water levels in the PL basin. Results of performance indicators in the lakes and lagoons were within the range of results available in the literature. Improvements of model performance metrics were verified with the inclusion of wind effect in the flow routing algorithm, thus encouraging the use of the proposed model for the establishment of flood forecasting systems or for the simulation of other similar hydrological systems. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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192. Modelling hydrologic and hydrodynamic processes in basins with large semi-arid wetlands.
- Author
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Fleischmann, Ayan, Siqueira, Vinícius, Paris, Adrien, Collischonn, Walter, Paiva, Rodrigo, Pontes, Paulo, Crétaux, Jean-François, Bergé-Nguyen, Muriel, Biancamaria, Sylvain, Gosset, Marielle, Calmant, Stephane, and Tanimoun, Bachir
- Subjects
- *
WATERSHEDS , *WETLANDS , *HYDROLOGY , *HYDRODYNAMICS , *ARID regions - Abstract
Hydrological and hydrodynamic models are core tools for simulation of large basins and complex river systems associated to wetlands. Recent studies have pointed towards the importance of online coupling strategies, representing feedbacks between floodplain inundation and vertical hydrology. Especially across semi-arid regions, soil-floodplain interactions can be strong. In this study, we included a two-way coupling scheme in a large scale hydrological-hydrodynamic model (MGB) and tested different model structures, in order to assess which processes are important to be simulated in large semi-arid wetlands and how these processes interact with water budget components. To demonstrate benefits from this coupling over a validation case, the model was applied to the Upper Niger River basin encompassing the Niger Inner Delta, a vast semi-arid wetland in the Sahel Desert. Simulation was carried out from 1999 to 2014 with daily TMPA 3B42 precipitation as forcing, using both in-situ and remotely sensed data for calibration and validation. Model outputs were in good agreement with discharge and water levels at stations both upstream and downstream of the Inner Delta (Nash-Sutcliffe Efficiency (NSE) >0.6 for most gauges), as well as for flooded areas within the Delta region (NSE = 0.6; r = 0.85). Model estimates of annual water losses across the Delta varied between 20.1 and 30.6 km 3 /yr, while annual evapotranspiration ranged between 760 mm/yr and 1130 mm/yr. Evaluation of model structure indicated that representation of both floodplain channels hydrodynamics (storage, bifurcations, lateral connections) and vertical hydrological processes (floodplain water infiltration into soil column; evapotranspiration from soil and vegetation and evaporation of open water) are necessary to correctly simulate flood wave attenuation and evapotranspiration along the basin. Two-way coupled models are necessary to better understand processes in large semi-arid wetlands. Finally, such coupled hydrologic and hydrodynamic modelling proves to be an important tool for integrated evaluation of hydrological processes in such poorly gauged, large scale basins. We hope that this model application provides new ways forward for large scale model development in such systems, involving semi-arid regions and complex floodplains. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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193. Assessing climate change impact on flood discharge in South America and the influence of its main drivers.
- Author
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Brêda, João Paulo L.F., Cauduro Dias de Paiva, Rodrigo, Siqueira, Vinicius Alencar, and Collischonn, Walter
- Subjects
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CLIMATE change models , *FLOODS , *CLIMATE change , *CLIMATE extremes , *RAINFALL , *HYDROLOGIC cycle , *EXTREME environments - Abstract
• Extreme rainfall events that lead to floods in large rivers are expected to decrease. • Antecedent soil moisture is expected to be reduced in most of South America. • Soil moisture seems more impactful than precipitation regarding ordinary floods. A warmer atmosphere is able to hold more water which consequently intensifies the hydrological cycle. The projected increase in extreme precipitation has been associated with greater floods; however, most recent studies have argued that the reduced soil moisture could be causing the opposite effect. We aim to understand how the hydrometeorological variables affect flood discharge and what the projections are for South America, a vulnerable continent that has been barely studied regarding flood trends. We used climate data from Eta simulations nested in 4 global climate models (BESM, CanESM2, HadGEM2-ES, MIROC5) as input for the MGB-SA hydrological model to yield flood discharge estimates. Then we were able to project the climate impacts on extreme precipitation, antecedent soil moisture, and flood discharge for large rivers (>1,000 km2) and understand how these variables are related. Our results showed a strong sign that antecedent soil moisture is expected to be reduced in most of the continent except in Southeastern South America (SESA). On the other hand, there are mixed signs for rarer precipitation and a clear spatial pattern for 2-year precipitations (RP2), which is expected to increase on the SESA and west Amazon and decrease on Central South America (CSA). For basins>100,000 km2, results indicate a negative change sign for 2-year precipitations, meaning that rainfall events that generate ordinary floods in large South American rivers are expected to decrease in the XXI century due to climate change. The change signs for flood discharge and extreme precipitation are spatially similar but more basins show a decrease for flooding than for rainfall. While only half of the South American basins are expected to present reduced 2-year precipitations, nearly 70 % of the rivers present a negative sign for 2-year floods, which can be attributed to the reduced antecedent soil moisture. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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194. Modelagem e previsão hidrológica em escala continental para a América do Sul
- Author
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Siqueira, Vinícius Alencar, Collischonn, Walter, and Paiva, Rodrigo Cauduro Dias de
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Bacia hidrográfica ,Geoprocessamento ,Modelagem hidrológica ,Previsão de vazões ,South America ,Recursos hídricos ,Hydrological modeling ,Ensemble ,MGB model ,América do Sul ,Forecasting - Abstract
A América do Sul (AS) possui uma área de ~17,8 milhões de km² e contribui com cerca de 30 % do volume total de água escoado para os oceanos. Gerenciar os recursos hídricos continentais na AS é uma tarefa desafiadora devido à heterogeneidade das características climáticas, suscetibilidade a cheias e secas, complexidade dos sistemas de rios e existência de usos múltiplos da água, em particular a produção de energia onde a hidroeletricidade corresponde por ~50 % da capacidade instalada na AS. Previsões de vazão, por exemplo, são essenciais para a operação de reservatórios e para melhorar a preparação contra eventos extremos, os quais podem ocorrer em múltiplas escalas espaciais e afetar extensas áreas inclusive para além de fronteiras políticas. Neste sentido, há necessidade de ferramentas que possibilitem quantificar fluxos hidrológicos com consistência espaço-temporal na AS, bem como prever a condição futura dos rios com estimativa de incerteza para dar suporte à tomada de decisão. O objetivo desta tese foi estabelecer uma base técnica para modelagem hidrológica com abrangência da América do Sul e dar contribuições para previsão de vazões em escala continental, no horizonte de médio prazo (até 15 dias). O modelo hidrológico MGB foi adaptado para simulação hidrológica–hidrodinâmica em múltiplas bacias sul americanas a partir de técnicas de geoprocessamento, produtos de sensoriamento remoto e outras bases de dados globais. O modelo desenvolvido, denominado MGB–SA, teve representação satisfatória de vazões em intervalo de tempo diário, apresentando acurácia superior à de modelos globais estado-da-arte. Também foram representados de forma adequada padrões de sazonalidade e magnitude de evapotranspiração e armazenamento terrestre de água nas principais bacias da AS, com desempenho razoável para os níveis simulados. Através de um experimento de previsão que assume o modelo hidrológico como livre de erros, foi identificado que previsões de chuva por conjunto (ensemble) com horizonte de médio prazo podem contribuir para a destreza das previsões de vazão com até 15 dias à frente. Na avaliação de desempenho geral das previsões de vazão, observou-se maior destreza para regiões situadas ao leste e sudeste da América do Sul, incluindo bacias como Uruguai, Alto Paraná, São Francisco, Parnaíba e Tocantins-Araguaia. Em relação à discriminação entre ocorrência e não ocorrência de eventos de vazão elevada, a destreza da previsão foi maior nos rios do sul do Brasil. Além disso, as previsões exibiram maior destreza para acurácia geral e discriminação em regiões de clima temperado e úmido (sub-tropical). Quando considerados ambos os erros do modelo hidrológico e da precipitação prevista, as previsões de vazão com horizonte de médio prazo demonstraram baixa ou nenhuma destreza na maioria das localidades analisadas além de um grande viés probabilístico, com a maior parte das observações situando-se fora dos limites do conjunto mesmo para antecedências mais longas após 1 semana à frente. Com aplicação de pós-processamento estatístico a destreza das previsões de vazão aumentou substancialmente, melhorando a consistência estatística e proporcionando largura de incerteza geralmente inferior ao da climatologia das vazões observadas. O desempenho de séries temporais de previsão por conjunto obtidas de distribuições preditivas pós-processadas também foi avaliado, demonstrando limitações principalmente em condições de baixo espalhamento do conjunto bruto. Por fim, os resultados deste trabalho sugerem que o modelo desenvolvido pode servir como uma ferramenta para dar suporte a pesquisas que contemplem os recursos hídricos da AS de forma integrada, e que previsões de vazão com destreza no horizonte de médio prazo podem ser obtidas na escala continental mesmo com dados in situ limitados. South America (SA) has an area of ~17.8 million km² and contributes around 30 % of the global runoff to the oceans. Managing the continental waters in SA is a challenge given the wide range of climatic characteristics, susceptibility to floods and droughts, complexity of river systems and existence of multiple water uses, in particular the energy production where hydropower accounts for ~50 % of the total installed capacity. Streamflow forecasts, for instance, are essential for reservoir operation and to improve preparedness against extreme hydrometeorological events, which can occur on multiple spatial scales and affect extensive regions including areas beyond the political boundaries. In this context, there is a need for tools that enable to quantify hydrological fluxes in SA with spatiotemporal consistency, as well as to predict future river conditions with uncertainty estimates to support decision making. The objective of this thesis was to establish a technical basis for hydrological modeling in the South America domain and contribute to medium-range (up to 15 days) streamflow forecasting at the continental scale. The MGB hydrological model was adapted for simulation of multiple South American basins by using hydrologic–hydrodynamic methods, geoprocessing techniques, remote sensing products and other global scale datasets. The developed model, named MGB–SA, showed a satisfactory representation of daily discharges and exhibited higher accuracy compared with state-of-the-art global models. Seasonality and magnitude of both evapotranspiration and terrestrial water storage were adequately represented at the scale of main SA basins, with a reasonable performance regarding the simulated water levels. Through a forecasting experiment that assumes the hydrological model as error-free, it was found that medium-range ensemble precipitation forecasts can contribute to the skill of streamflow forecasts up to 15 days ahead. Overall skill was higher in the eastern and southeastern SA regions, which include large basins such as Uruguay, Upper Paraná, São Francisco, Parnaíba and Tocantins-Araguaia. Skill in discrimination between the occurrence and non-occurrence of high flow events was mainly observed in rivers of southern Brazil. In addition, forecasts showed better skill in terms of overall quality and discrimination in warm temperate, fully humid regions. When the errors of both hydrological model and predicted precipitation were taken into account, medium-range streamflow forecasts exhibited low or no skill in most of the analyzed locations in addition to a large probabilistic bias, with most of the observations falling outside the ensemble limits even at longer lead times, after 1 week ahead. Statistical postprocessing substantially improved streamflow forecast skill, enhancing statistical consistency and generally providing lower uncertainty width compared with that of observed climatology. The performance of streamflow ensemble traces derived from postprocessed predictive distributions was also evaluated, showing limitations mainly in conditions for which the raw ensemble spread is low. Finally, the results of this work suggest that the developed model can be used to simulate the South American water resources in an integrated manner, and that skillful, medium-range streamflow forecasts could be obtained at the continental scale of SA even with limited in situ data.
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- 2022
195. Simulação hidrológica de grandes bacias semiáridas com densas redes de açudes e poucos dados
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Andrade Neto, Julio Vitorino and Collischonn, Walter
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Reservatórios ,Bacia hidrográfica ,Semi-arid ,Semi-Árido, Região ,Modelo MGB-IPH ,Dados hidrológicos ,Hydrological model ,Modelos hidrológicos ,Reservoir - Abstract
A região semiárida do Brasil apresenta um regime de precipitação com alta variabilidade espacial e temporal, além de elevada evaporação potencial, o que limita a disponibilidade de água para as atividades econômicas. Uma solução historicamente adotada para este problema, tanto pelo Estado como por empreendedores individuais, foi a construção de reservatórios, estruturas capazes de transpor a disponibilidade hídrica no tempo, de um período chuvoso para um seco. No Nordeste brasileiro, o processo de construção de açudes se iniciou ainda no século XIX e hoje há mais de 105.000 barramentos apenas no estado do Ceará, com predominância dos de pequeno porte. Essa densa rede de reservatórios é de difícil gestão, pois pouco se sabe sobre as características de cada estrutura e sobre as interações e efeitos sobre a hidrologia local. Modelos hidrológicos surgem como uma solução para este problema, porém, em sua maioria, não são idealizados para incorporar estruturas antrópicas em seu escopo, a exemplo do Modelo de Grandes Bacias (MGB-IPH). Assim, este trabalho tem o objetivo de desenvolver um módulo de reservatórios para incorporação ao MGB-IPH visando à modelagem de bacias hidrográficas de grande escala considerando densas redes de pequenos reservatórios sobre as quais existe pouco ou nenhum dado. Para isso, foram desenvolvidas metodologias de análise e geração de dados sobre pequenos reservatórios distribuídos sobre a sub-bacia do Banabuiú, bacia adotada para estudo de caso. Primeiramente, foram investigadas as relações e a influência de diferentes formas de representação dos açudes dentro do modelo, variando-se a quantidade de açudes representados explicitamente (on-grid) e a quantidade utilizada para gerar os açudes equivalentes (aqueles em sub-grid) através da utilização de diferentes densidades de drenagem. Em relação ao reservatório equivalente, foi feita uma comparação entre a metodologia proposta da tabela incremental que considera as respectivas áreas de contribuição de cada açude, bem como as interações entre eles; com uma versão alternativa que considerava os reservatórios equivalentes no exutório de cada minibacia. Por fim, foram analisados diferentes cenários de interação entre pequenos e grandes reservatórios através de curvas de permanência de atendimento a demandas. A partir dos resultados obtidos, pode-se inferir que a utilização de maiores densidades de drenagem foi a abordagem mais adequada, apresentando os melhores resultados globais do coeficiente de Nash-Sutcliffe (NS) para a bacia. Por sua vez, na comparação entre os reservatórios equivalentes, a metodologia proposta apresentou-se a mais adequada, sendo capaz de melhorar globalmente os coeficientes do modelo. Quanto às curvas de permanência, observou-se que a presença dos pequenos reservatórios reduz a entrada de água nos reservatórios estratégicos, diminuindo a capacidade destes açudes de atender às demandas da bacia. Dessa forma, embora existam limitações quanto aos resultados apresentados, observa-se que houve um considerável avanço na modelagem desses tipos de bacias dentro do modelo MGB-IPH. The semi-arid region of Brazil presents a precipitation regime with high spatial and temporal variability, in addition to high potential evaporation ratings, which limits the availability of water for economic activities. A historical solution adopted to solve this problem, both by the State and by individual entrepreneurs, was the construction of reservoirs. These structures are capable of transferring water availability over time, from a wet period to a dry one. In the Brazilian Northeast, the process of construction of these dams date back to the 19th century and nowadays there are more than 105.000 dams in the state of Ceará alone, being the small ones predominant. This dense network of reservoirs is difficult to manage, as little is known about the characteristics of each structure and the interactions and effects on local hydrology. Hydrological models emerge as a solution to this problem. However, for the most part, they are not designed to incorporate anthropic structures in their scope, such as the Modelo de Grandes Bacias (MGB-IPH). Hence, the goal of this paper is to develop a reservoir module for incorporation into the MGB-IPH aiming at modeling large-scale hydrographic basins considering dense networks of small reservoirs on which little or no data exists. On this context, a methodology for analysis and data generation was developed and applied on the group of small reservoirs distributed over the Banabuiú sub-basin, adopted as a case study. Firstly, the relationships and influence of different forms of representation of the dams within the model were investigated, varying the amount of dams represented explicitly (on-grid) and the amount used to generate the equivalent dams (those in sub-grid). These analyses were made by using different drainage densities. In relation to the equivalent reservoir, an incremental table methodology was proposed, considering the respective areas of contribution of each dam, as well as the interactions between them. Then, a comparison was made between this methodology and an alternative version that considered equivalent reservoirs at the outlet of each mini-basin. Finally, different scenarios of interaction between small and large reservoirs were analyzed through demand permanence curves. From the results obtained, it can be inferred that the use of higher drainage densities was the most appropriate approach, presenting the best overall results of the Nash-Sutcliffe coefficient. In the comparison between equivalent reservoirs, the proposed methodology was the most adequate, being able to globally improve the coefficients of the model. As for the permanence curves, it was observed that the presence of small reservoirs reduces the entry of water into strategic reservoirs, reducing their capacity to supply the basin needs. Thus, although there are limitations regarding the results presented, it is observed that there has been a considerable advance in the modeling of these types of basins within the MGB-IPH model.
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- 2022
196. Large-scale assessment of groundwater reserves and processes in Brazil, South America
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Melati, Maurício Dambrós, Fan, Fernando Mainardi, and Collischonn, Walter
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Recarga aquífera ,GRACE Mascon ,Bacias hidrográficas brasileiras ,RIMAS network ,Hidrogeologia ,Groundwater Recharge ,Serra Geral, Sistema Aquífero ,Caiuá, Aquífero (PR) ,MGB model ,GRACE ,Sensoriamento remoto ,Clima ,Aquifer-river Interactions ,Modelos hidrológicos - Abstract
As reservas de água subterrânea estão entre os componentes do balanço hídrico com maior incerteza de quantificação. O entendimento da sua disponibilidade ainda é limitado em comparação com outras reservas hídricas como rios, atmosfera, solo e lagos. A busca por esse recurso tem aumentado tanto nas áreas úmidas quanto nas áreas secas. Explorar os processos de interação entre as águas subterrâneas e os rios em aquíferos de grande escala (como o comportamento das reservas em períodos secos, eventos de recarga episódica e variabilidade anual), é de grande interesse para a indústria, a economia e a qualidade de vida da população. O desenvolvimento e a avaliação de ferramentas é um passo inicial para o uso sustentável das águas subterrâneas. O objetivo desta tese é avançar no entendimento de processos hidrogeológicos de grande escala que ocorrem no Brasil em diferentes climas e formações aquíferas a partir de ferramentas inovadoras e complementares de monitoramento in situ, dados de sensoriamento remoto e modelagem hidrológica. Verificou-se que o uso do GRACE para detectar variações nas reservas de água subterrânea para um aquífero sedimentar no semiárido brasileiro apresentou resultados adequados. As reservas de água subterrânea estão entre os componentes do balanço hídrico com maior incerteza de quantificação. O entendimento da sua disponibilidade ainda é limitado em comparação com outras reservas hídricas como rios, atmosfera, solo e lagos. A busca por esse recurso tem aumentado tanto nas áreas úmidas quanto nas áreas secas. Explorar os processos de interação entre as águas subterrâneas e os rios em aquíferos de grande escala (como o comportamento das reservas em períodos secos, eventos de recarga episódica e variabilidade anual), é de grande interesse para a indústria, a economia e a qualidade de vida da população. O desenvolvimento e a avaliação de ferramentas é um passo inicial para o uso sustentável das águas subterrâneas. O objetivo desta tese é avançar no entendimento de processos hidrogeológicos de grande escala que ocorrem no Brasil em diferentes climas e formações aquíferas a partir de ferramentas inovadoras e complementares de monitoramento in situ, dados de sensoriamento remoto e modelagem hidrológica. Verificou-se que o uso do GRACE para detectar variações nas reservas de água subterrânea para um aquífero sedimentar no semiárido brasileiro apresentou resultados adequados. Groundwater volumes are among the water balance components with the greatest uncertainty of quantification, the understanding of its availability is still limited compared to other water reserves such as rivers, atmosphere, soil, and lakes. The search for this continuous supply resource throughout the year has increased in wet and dry areas. Exploring hydrological, hydrogeological, and surface-groundwater interaction processes among these large-scale South American aquifers, such as the dynamics associated with dry periods response, recharge events, and interannual variability, is of great interest to the industry, the economy, and the quality of life of the regional population. And the development and testing of tools for researching these aspects is a primer step for sustainable usage of groundwaters in the South American domain. The main objective of this thesis is to advance in the determination of large-scale hydrogeological process in Brazil, South America in different climates and aquifer formations from innovative and complementary tooling of intensive field monitoring, remote sensing data, and hydrological modeling. We found that the use of GRACE to detect variations in groundwater reserves showed adequate results for a small-scale sedimentary aquifer in the Brazilian semi-arid region. The findings were promising to improve the understanding of droughts at different scales in those areas. GRACE data also showed itself as an essential tool for monitoring groundwater volumes in the other two aquifers in humid subtropical areas and investigated in this thesis (Caiuá Aquifer and SASG). We also found that in those humid subtropical areas, the high soil moisture storage has an important role in the occurrence of large episodic recharge events. Atypical rainfall in winter periods was responsible for the increase in soil moisture that explains the larger events. The changes in aquifer storage caused by episodic recharge events are long-lasting and directly affect low flows in rivers with implications on hydro-climatic variability. We also brought important findings related to groundwater variations in fractured aquifer systems, which are complex to predict. Significant contributions related to groundwater level variations, transit times, regional trends, and interaction with the rivers in the SASG were presented.
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- 2022
197. MGB-IPH model for hydrological and hydraulic simulation of large floodplain river systems coupled with open source GIS.
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Pontes, Paulo Rógenes Monteiro, Fan, Fernando Mainardi, Fleischmann, Ayan Santos, de Paiva, Rodrigo Cauduro Dias, Buarque, Diogo Costa, Siqueira, Vinícius Alencar, Jardim, Pedro Frediani, Sorribas, Mino Viana, and Collischonn, Walter
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FLOODPLAINS , *COMPUTER simulation , *MATHEMATICAL models , *WATERSHEDS , *GEOGRAPHIC information system software - Abstract
Large-scale hydrological models are useful tools for water resources studies, however, river network flow routing is generally represented using simplified methods, which may lead to simulation errors in flat regions. We present recent improvements to the large-scale hydrological model MGB-IPH to improve its capability of simulating large river basins with extensive floodplains. We also describe the coupling of MGB-IPH to an open source GIS and a large set of developed pre-processing tools with a user-friendly interface for remote sensing data preparation and output visualization. The new features implemented are demonstrated applying the model to the whole Araguaia river basin (380,000 km 2 ). Results are compared to the previous MGB-IPH routing method, observed flow and water level data and remote sensing imagery, showing improvement in the representation of floodplain inundation dynamics. The test case also shows that the proposed model software framework amplifies possibilities of large-scale simulation of ungauged basins. [ABSTRACT FROM AUTHOR]
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- 2017
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198. Multi-decadal Hydrological Retrospective: Case study of Amazon floods and droughts.
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Wongchuig Correa, Sly, Paiva, Rodrigo Cauduro Dias de, Espinoza, Jhan Carlo, and Collischonn, Walter
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FLOODS , *DROUGHTS , *CLIMATE change , *RAINFALL , *HYDROLOGY - Abstract
Recently developed methodologies such as climate reanalysis make it possible to create a historical record of climate systems. This paper proposes a methodology called Hydrological Retrospective (HR), which essentially simulates large rainfall datasets, using this as input into hydrological models to develop a record of past hydrology, making it possible to analyze past floods and droughts. We developed a methodology for the Amazon basin, where studies have shown an increase in the intensity and frequency of hydrological extreme events in recent decades. We used eight large precipitation datasets (more than 30 years) as input for a large scale hydrological and hydrodynamic model (MGB-IPH). HR products were then validated against several in situ discharge gauges controlling the main Amazon sub-basins, focusing on maximum and minimum events. For the most accurate HR, based on performance metrics, we performed a forecast skill of HR to detect floods and droughts, comparing the results with in-situ observations. A statistical temporal series trend was performed for intensity of seasonal floods and droughts in the entire Amazon basin. Results indicate that HR could represent most past extreme events well, compared with in-situ observed data, and was consistent with many events reported in literature. Because of their flow duration, some minor regional events were not reported in literature but were captured by HR. To represent past regional hydrology and seasonal hydrological extreme events, we believe it is feasible to use some large precipitation datasets such as i) climate reanalysis, which is mainly based on a land surface component, and ii) datasets based on merged products. A significant upward trend in intensity was seen in maximum annual discharge (related to floods) in western and northwestern regions and for minimum annual discharge (related to droughts) in south and central-south regions of the Amazon basin. Because of the global coverage of rainfall datasets, this methodology can be transferred to other regions for better estimation of future hydrological behavior and its impact on society. [ABSTRACT FROM AUTHOR]
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- 2017
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199. A comprehensive strategy for modeling watershed restoration priority areas under epistemic uncertainty: A case study in the Atlantic Forest, Brazil.
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Possantti, Iporã, Barbedo, Rafael, Kronbauer, Marcelo, Collischonn, Walter, and Marques, Guilherme
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EPISTEMIC uncertainty , *WATERSHED restoration , *LAND cover , *PAYMENTS for ecosystem services , *COST allocation , *ECOSYSTEM services - Abstract
Hydrological models are useful to support ecosystem services restoration. However, when planning the expansion of Nature-based Solutions and Payments for Ecosystem Services, there are requirements including the principle of additionality, representation of multiple runoff mechanisms and calculation of farm-scale spatial outputs and epistemic uncertainty. While addressing these aspects is important to make future planning more effective (investment costs and water benefits) it is also challenging. This paper integrates, in a single modeling framework, the main requirements highlighted. This allows an improved selection of top priority areas with farm-scale spatial resolution and a deeper understanding of how epistemic modeling uncertainty affects the results, which is relevant to evaluate the risks of overestimating ecosystem services benefits. The modeling approach is demonstrated in a case study watershed in the Atlantic Forest biome (Brazil). The PLANS model is introduced, which uses the design of TOPMODEL to simulate both simulates both saturation-excess and infiltration-excess runoff at the farm-scale resolution. Also, it uses a novel saturation index based in a composition of Height Above the Nearest Drainage and Topographical Wetness Index terrain descriptors. We applied the Generalized Likelihood Uncertainty Estimation method, aided by an evolutionary algorithm, to estimate output epistemic uncertainty. Results show that uncertainty substantially affects priority definition (97% ranking change), and that simulated topographic effects can overcome local effects of land cover and soil type. With better data, uncertainty evaluation indicates that the restoration program in the study case could have the cost of its allocation policy reduced by up to 27%, showing that it can be made more cost- effective with the methods proposed. [Display omitted] [ABSTRACT FROM AUTHOR]
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- 2023
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200. Inundações em múltiplas escalas na América do Sul : de áreas úmidas a áreas de risco
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Fleischmann, Ayan Santos, Collischonn, Walter, Paiva, Rodrigo Cauduro Dias de, and Papa, Fabrice
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Amazônia ,Interfluvial wetlandsl ,Planície de inundação ,Inundation ,Modelo MGB-IPH ,Sensoriamento remoto ,Banhados ,River floodplains ,Modelos hidrológicos ,América do Sul - Abstract
A América do Sul abriga alguns dos maiores sistemas hídricos do planeta, frequentemente associados a grandes planícies de inundação, como o Pantanal e várias áreas da Amazônia. Áreas úmidas (AU’s) interfluviais são também encontrados no continente, com características geomorfológicas particulares, e vegetações de savana e gramíneas únicas. As AU’s da América do Sul provêm diversos serviços ecossistêmicos, como suporte à biodiversidade, provisão de alimento e atenuação de cheias. Humanos têm se estabelecido ao redor de AU’s por milênios, se beneficiando dos recursos providos por elas. Eles se adaptaram ao seu regime de inundação, e adaptaram sua paisagem, definindo o que tem sido chamado de sistemas sociedade-água. Por outro lado, um número crescente de pessoas têm sido negativamente afetado por cheias extremas. Da escala continental à local, esta tese convida o leitor a uma jornada através de importantes AU’s da América do Sul e suas particulares dinâmicas de inundação, sob a luz da era dos satélites e dos grandes avanços em modelagem hidrológica-hidrodinâmica das últimas décadas. Este trabalho é baseado na proposta de uma escala continental de pesquisa sobre AU’s, e é baseado em uma abordagem de hidrologia comparativa. Inundações são estudadas em múltiplas dimensões, de processos de AU’s naturais à questão do perigo para humanos. A primeira parte apresenta uma série de estudos sobre as AU’s da bacia amazônica, desde o desenvolvimento de modelos 1D e 2D para simular processos hidrológicos em tipos contrastantes de AU’s na bacia do Rio Negro, até a intercomparação de 29 produtos de inundação e avaliação de tendências de inundações de longo prazo para a escala da bacia amazônica. Enquanto a maioria dos estudos de AU’s foi conduzida nas várzeas do rio Amazonas, importantes lacunas do conhecimento permanecem para a compreensão da dinâmica hidrológica de áreas interfluviais como Llanos de Moxos e as savanas do rio Negro, onde a inundação é menos previsível e mais rasa. A segunda parte da tese utiliza dados oriundos de satélites relacionados a múltiplas variáveis hidrológicas (níveis d’água, armazenamento total de água, extensão de áreas inundadas, precipitação e evapotranspiração) para estudar a hidrologia de 12 grandes sistemas de AU’s do continente. São destacadas as grandes diferenças entre planícies de inundação e AU’s interfluviais em termos de amplitude anual de níveis d’água, defasagem entre precipitação e inundação, e dinâmica de evapotranspiração. Por fim, a última parte da tese aborda o componente de perigo de inundação das interações sociedade-água através de avaliações em grande escala da dinâmica de inundação e dos efeitos de infraestruturas construídas (como barragens) na atenuação de cheias. A dinâmica das grandes cheias de 1983, um dos anos mais extremos já registrados no continente, é avaliada com um modelo hidrológico continental. Depois, a capacidade de modelos continentais para simular o continuum entre rios, planícies de inundação e reservatórios que existe em grandes bacias hidrográficas é avaliada com estudos de casos para importantes bacias afetadas pela intervenção humana (bacia dos rios Paraná e Itajaí-Açu). Enquanto esta tese avança a compreensão de relevantes processos hidrológicos relacionados a inundações na América do Sul em múltiplas escalas, bem como seus efeitos positivos e negativos nas sociedades humanas e ecossistemas em geral, importantes lacunas do conhecimento persistem e fomentam importantes oportunidades de pesquisa futuras. O lançamento de várias missões satelitais orientadas a hidrologia, e uma cada vez mais crescente capacidade computacional, faz da agenda continental de hidrologia relacionada a AU’s e inundações um grande tópico de pesquisa para os próximos anos. South America hosts some of the major river systems on Earth, often associated with large floodplains that are inundated every year, such as the Pantanal and many Amazon wetlands. Interfluvial wetland complexes are also found across the continent, with particular geomorphic settings and unique savanna or grassland vegetation. South American wetlands can provide distinctive ecosystem services such as biodiversity supporting, food provision and flood attenuation. On the other hand, humans have settled around wetlands for millennia, benefiting from all resources they provide, and have adapted to its flood regime as well adapted its landscape, defining what has been called human-water systems. Yet, an increasing number of South American people have been negatively affected by extreme floods. Moving from continental to local scales, this thesis invites the readers to a journey across major South American wetland systems and their unique hydrological dynamics, under the light of the satellite era and the breakthrough advances on hydrologic-hydrodynamic modeling in the last decades. This work is founded on the proposition of a continental wetland research agenda, and based on a comparative hydrology approach. Floods are studied through both natural wetland processes and hazard dimensions. The first part presents a set of studies on the Amazon basin wetlands, from the development of 1D and 2D models to simulate hydrological processes in contrasting wetland types in the Negro river basin to the basin-wide intercomparison of 29 inundation products and assessment of long-term inundation trends. While most wetland studies have been conducted over the central Amazon floodplains, major knowledge gaps remain for understanding the hydrological dynamics of interfluvial areas such as the Llanos de Moxos and Negro savannas, where the inundation is less predictable and shallower. The second part of the thesis leverages satellite-based datasets of multiple hydrological variables (water levels, total water storage, inundation extent, precipitation and evapotranspiration) to address the hydrology of 12 large wetland systems in the continent. It shows the major differences among river floodplains and interfluvial wetlands on the water level annual amplitude, time lag between precipitation and inundation, and evapotranspiration dynamics. Finally, the third part addresses the flood hazard component of human-wetland interactions through large-scale assessments of flood hazard dynamics and effects of built infrastructure (dams) on flood attenuation. The dynamics of the great 1983 floods, one of the most extreme years ever recorded in the continent, is assessed with a continental hydrological model. Then, the capabilities of continental models to simulate the river-floodplain-reservoir continuum that exists across large river basins are assessed with case studies for major river basins affected by human intervention (Itajaí-Açu and upper Paraná river basins in Brazil). While this thesis enlightens some relevant hydrological processes regarding South American floods and their positive and negative effects to human societies and ecosystems in general, major knowledge gaps persist and provide great research opportunities for the near future. The launching of many hydrology-oriented satellite missions, and an ever-growing computational capacity, make the continental hydrology agenda related to wetlands and floods a great research topic for the upcoming years.
- Published
- 2021
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