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Brasília, Brazil

Coelho A.C.,Agencia Nacional de Aguas | Labadie J.W.,Colorado State University | Fontane D.G.,Colorado State University
Water Resources Management | Year: 2012

Successful implementation of integrated water resources planning and management (IWRM) requires delineation of regions that are relatively homogeneous with respect to multiple criteria, including hydrographic, physical-environmental, socioeconomic, and political-administrative aspects. The water resources planning and management (WARPLAM) DSS is presented as tool for regionalization in support of IWRM through: (1) GIS processing of spatial data related to multiple criteria for defining the homogeneity of clustered base units (e.g., catchments) with respect to multiple criteria; (2) application of fuzzy set theory to development of composite measures of homogeneity over all criteria for alternative clustering of adjacent base units; and (3) development of a modified dynamic programming clustering algorithm that guarantees consistent optimal solutions based on user preferences on the relative importance of the suite of criteria considered for regionalization. The viability of WARPLAM DSS as a tool for regional delineation in support of IWRM is demonstrated through a case study application to the Tocantins-Araguaia River Basin, the second largest in Brazil. © 2012 Springer Science+Business Media B.V. Source

de Souza F.A.O.,Agencia Nacional de Aguas | da Silva C.L.,University of Brasilia | Maggiotto S.R.,University of Brasilia | de Oliveira Junior M.P.,University of Brasilia
Revista Brasileira de Engenharia Agricola e Ambiental | Year: 2012

In Brazil, Distrito Federal region is characterized by the presence of streamlets and small rivers, which explains the importance of the discharge characterization in watersheds. This study used 13 years of hydrological data of the Capetinga watershed to analyze: the stationarity of hydrological parameters; the statistical distributions that best represent the discharge; the comparison of using short and medium series to calculate discharge; and the requirement for water rights concession according to the current legislation. The Lognormal 3 and Pearson 3 distributions best represented the maximum discharge, while Logpearson 3 distribution was best indicated for minimum discharge. Total annual precipitation, long duration mean discharge and seven-day minimum flow presented stationary series, but maximum instantaneous discharge did not. The use of short series to calculate discharge in this watershed was not reasonable, since it resulted in overestimation of the minimum discharge and underestimation of the maximum discharge. According to the legislation, the water capturing from the stream Capetinga requires a concession from the regulatory agency, in spite of the minimum discharge has a small value, which reflects its low potential of use. Source

Paz A.R.,Federal University of Paraiba | Serra L.S.,Federal University of Paraiba | Silva M.R.F.,Federal University of Paraiba | Meller A.,Agencia Nacional de Aguas
Journal of Hydrologic Engineering | Year: 2016

Coupling rainfall-runoff and one-dimensional (1D)/two-dimensional (2D) hydrologic models provides the current state-of-the-art approach for predicting the extent of urban inundation, although the computational cost for running 2D models is still a major concern. This paper presents a procedure to dynamically reshape 2D numeric domain according to flooding extent evolution. The numeric domain is updated at each selected time step for reshaping (TSR) and includes grid elements directly connected to the 1D stormwater network, flooded grid elements, or grid elements within a buffer distance threshold (BDT) identified in both previous criteria. Results for an urban catchment in South Brazil are presented considering two spatial resolutions and three return-period rainfall events. An optimal relation between TSR and BDT was found and resulted in runtime savings greater than 86% in comparison to adopting a fixed boundary as catchment limits, and greater than 69% in comparison to using a fixed boundary below the 70-m elevation (which represents the maximum elevation reached by the 100-year flood). The major concepts of the proposed algorithm are straightforward and could be tested in similar 2D models. © ASCE. Source

Espinoza Villar R.,University of Brasilia | Martinez J.-M.,University of Brasilia | Martinez J.-M.,University Paul Sabatier | Martinez J.-M.,Brazilian Radiological Protection and Dosimetry Institute (IRD) | And 8 more authors.
Journal of South American Earth Sciences | Year: 2013

The Madeira River may contribute nearly half of the Amazon River sediment discharge to the Atlantic Ocean, showing the highest erosion rates in the Amazon Basin. However, few studies have assessed the Madeira River sediment budget and the transport processes occurring in the main stem of the river. In this study, MODIS space-borne sensors were used to analyze the suspended sediment transport processes along the main stem of the Madeira River. Field measurements of suspended sediment concentration, spectral radiometry and granulometry were performed during 10 cruises from 2007 to 2011. The relationship between the spectral reflectance and the surface suspended sediment concentration (SSSC) was analyzed using both field radiometric measurements and satellite data. Ten-day SSSC samples acquired by the HYBAM monitoring network were used to match satellite observations with field measurements performed from 2000 to 2011. Over 900 MODIS images of 6 different locations were processed to monitor the SSSC dynamics in space and time. Satellite reflectance was found to be significantly correlated with the SSSC. However, a seasonal dependency was demonstrated, most likely caused by a variable granulometric distribution along the annual cycle. The ratio between the red and near-infrared bands was found to be free of the seasonal dependency (r = 0.79, N = 282), and a SSSC retrieval model was built from the satellite data using a bootstrap resampling technique. The satellite-retrieved SSSC time series showed excellent accuracy over the 11-year period and at two different stations located 800 km from each other. The satellite data were averaged to analyze the SSSC pattern temporally and spatially along the entire Madeira River, which provided evidence of significant sedimentation and resuspension. The backwater effect caused by the two-to-three-month lag between peak water in the Madeira and Amazon Rivers was used to predict local sedimentation near the Madeira River mouth. Our results facilitated a precise assessment of such sedimentation, which demonstrated an SSSC decrease 400 km upstream from the Madeira-Amazon confluence. © 2013 Elsevier Ltd. Source

The development of aquifer artificial recharge projects brings two main concerns: the groundwater contamination risk and, in the case of thermal systems, the risk of water cooling. The present study presents, from a semi-quantitative perspective, an analysis of the risk of temperature reduction of the thermal aquifer at the Caldas Novas region, state of Goiás, Brazil. The local groundwater reservoirs are classified as thermal artesian fractured aquifer systems. Three different aquifer systems are individualized: Intergranular, Paranoá and Araxá. The permanent reserves of the Paranoá and Araxá Aquifers Systems were estimated in 1,8 × 108 m3 and 4,5 × 107 m3, respectively, and the renewable reserves as 2,25 × 106 m 3/year, for Araxá, and 9,0 × 106 m 3/year, for Paranoá. These were compared to different volumes of artificial recharge water, and showed that, on a global view, there is no risk of temperature reduction for these waters, since the volumes of recharge are insignificant when compared to the reservoir. However, it is possible to find some heat loss in the surroundings of the wells that were used for the water injection, because the mixture of waters is not instantaneous and the water injected in each well affects a restricted volume of the aquifer. It had also been proposed the delimitation of the hydrogeological basin associated to the control of the hydrothermal system present in the central region of Caldas Novas. The set of available information shows that, regarding the temperature issue, the artificial recharge of the thermal aquifers is viable. Source

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