Claudio José Cavalcante Blanco

Decision support system for micro-hydro power plants in the Amazon region under a sustainable development perspective

One of the main obstacles to the socio-economic development of the Brazilian Amazon is the lack of electric energy in the numerous small isolated communities of the region that hampers value-added agricultural production, revenue growth and creation of jobs. One way to solve this problem is by setting up micro-hydro power (MHP) plants under a sustainable development perspective. This paper presents a decision support system (DSS) that analyzes this solution. The system considers the hydrological, topographical, geotechnical, environmental, energy, economic and social aspects of the target site. A detailed analysis is made of the hydrological model that employs a rainfall run-off model for small catchment analysis; the energy planning favors a two-turbine method to determine the maximum energy production during demand peaks, and the economic aspects show that the costs of energy generated by MHP plants are comparable to those from rural grid systems and lower than those from from diesel generators. Thus, the use of the hydro-power resources of the small catchments of Amazonia combined with the minimization of the environmental impacts caused by MHP not only fulfills the energy demand of the small communities of region, but is also viable economically along with job creation and revenue generation, and it supports the perspective of sustainable development.

A water flow pattern analysis of Guajará Bay: Amazon Estuary - Brazil

This work describes the steps required to construct a hydrodynamic model of the Guajara Bay, using Geographic Information Systems and the Finite Element Method. An overview of the problem that motivates this modelling procedure, i.e., the pollutant dispersion, is presented. The computer software used is then discussed, stressing the links between the data model entities. The calibration procedure is described. The methods used to obtain field data and the results obtained are presented, alongside the main flow patterns of the water. The simulations and applications of the model are discussed at the end of the paper.

Hydrodynamic modeling and morphological analysis of Lake Água Preta: one of the water sources of Belém-PA-Brazil

The main contribution from this paper includes the hydrodynamic modeling and morphological analysis of Lake Agua Preta in Belem city, Para State, Brazil. The lake bathymetry was taken through the data provided by COSANPA (the local sanitation and water supply company) dating back to 1975, and from a 2009 field study. Both bathymetries produced two terrain elevation models, which were used for morphological analysis and hydrodynamic simulations. The morphological analysis has revealed that, from 1975 to 2009, the annual mean rate of sedimentation varies between 23,065 and 29,081 m3/year. Through this result, the sedimentation time of Lake Agua Preta, from 2009, has been calculated, which varies between 295 and 381 years, maintaining the same rate of sedimentation, water consumption and pumping. The hydrodynamic model simulated the depths and velocities, showing a slight flow with velocities ranging from 0 to 33 cm/s. This flow is established between water input and output of the lake, which is used as reservoir of Belem city.

Modelagem Sísmica via métodos das diferenças finitas: caso da bacia do Amazonas

Este trabalho tem por objetivo apresentar os resultados da modelagem sismica em meios com fortes descontinuidades de propriedades fisicas, com enfase na existencia de difracoes e multiplas reflexoes, tendo a Bacia do Amazonas como referencia a modelagem. As condicoes de estabilidade e de fronteiras utilizadas no calculo do campo de ondas sismicas foram analisadas numericamente pelo metodo das diferencas finitas, visando melhor compreensao e controle da interpretacao de dados sismicos. A geologia da Bacia do Amazonas e constituida por rochas sedimentares depositadas desde o Ordoviciano ate o Recente que atingem espessuras da ordem de 5 km. Os corpos de diabasio, presentes entre os sedimentos paleozoicos, estao dispostos na forma de soleiras, alcancam espessuras de centenas de metros e perfazem um volume total de aproximadamente 90000 Km³. A ocorrencia de tais estruturas e responsavel pela existencia de reflexoes multiplas durante a propagacao da onda sismica o que impossibilita melhor interpretacao dos horizontes refletores que se encontram abaixo destas soleiras. Para representar situacoes geologicas desse tipo foram usados um modelo (sintetico) acustico de velocidades e um codigo computacional elaborado via metodo das diferencas finitas com aproximacao de quarta ordem no espaco e no tempo da equacao da onda. A aplicacao dos metodos de diferencas finitas para o estudo de propagacao de ondas sismicas melhorou a compreensao sobre a propagacao em meios onde existem heterogeneidades significativas, tendo como resultado boa resolucao na interpretacao dos eventos de reflexao sismica em areas de interesse. Como resultado dos experimentos numericos realizados em meio de geologia complexa, foi observada a influencia significativa das reflexoes multiplas devido a camada de alta velocidade, isto provocou maior perda de energia e dificultou a interpretacao dos alvos. Por esta razao recomenda-se a integracao de dados de superficie com os de poco, com o objetivo de obter melhor imagem dos alvos abaixo das soleiras de diabasio.

Transférabilité d’un modèle pluie–débit pour la simulation de courbes de débits classés sur des petits bassins non jaugés de l’Amazonie

In Amazonia, because the small catchments are ungauged, it is not possible to analyse them, for example, for hydroelectric power production. Thus, the objective of this paper is to study the transferability of a rainfall–runoff model to simulate flow duration curves for the production of hydroelectric power. The approach is based on the transfer of the impulse response of a model calibrated on two gauged catchments, allowing the evaluation approach permutation between these two catchments. We have, respectively, 7 years and 2 years and 2 months of rainfall and runoff data for these catchments. A sensitivity analysis of the transferability calibration to the sample size is carried out to determine the shortest flow period gauged on the receptor catchment, which produces results comparable to those calibrated with the maximum samples size. This analysis evaluates fieldwork on the ungauged sites of the region.

An Analysis of Total Phosphorus Dispersion in Lake Used As a Municipal Water Supply

In Belém city is located the potable water supply system of its metropolitan area, which includes, in addition to this city, four more municipalities. In this water supply complex is the Água Preta lake, which serves as a reservoir for the water pumped from the Guamá river. Due to the great importance of this lake for this system, several works have been devoted to its study, from the monitoring of the quality of its waters to its hydrodynamic modeling. This paper presents the results obtained by computer simulation of the phosphorus dispersion within this reservoir by the numerical solution of two-dimensional equation of advection-diffusion-reaction by the method θ/SUPG. Comparing these results with data concentration of total phosphorus collected from November 2008 to October 2009 and from satellite photos show that the biggest polluters of the water of this lake are the domestic sewage dumps from the population living in its vicinity. The results obtained indicate the need for more information for more precise quantitative analysis. However, they show that the phosphorus brought by the Guamá river water is consumed in an area adjacent to the canal that carries this water into the lake. Phosphorus deposits in the lake bottom should be monitored to verify their behavior, thus preventing the quality of water maintained therein.

Contribution to hydrological modelling of small Amazonian catchments: application of rainfall–runoff models to simulate flow duration curves

Abstract The objective of this study is to analyse three rainfall–runoff hydrological models applied in two small catchments in the Amazon region to simulate flow duration curves (FDCs). The simple linear model (SLM) considers the rainfall–runoff process as an input–output time-invariant system. However, the rainfall–runoff process is nonlinear; thus, a modification is applied to the SLM based on the residual relationship between the simulated and observed discharges, generating the modified linear model (MLM). In the third model (SVM), the nonlinearity due to infiltration and evapotranspiration is incorporated into the system through the sigmoid variable gain factor. The performance criteria adopted were a distance metric (δ) and the Nash-Sutcliffe coefficient (R2) determined between simulated and observed flows. The good results of the models, mainly the MLM and SVM, showed that they could be applied to simulate FDCs in small catchments in the Amazon region. Editor D. Koutsoyiannis; Associate editor A. Montanari Citation Blanco, C.J.C., Santos, S.S.M., Quintas, M.C., Vinagre, M.V.A., and Mesquita, A.L.A., 2013. Contribution to hydrological modelling of small Amazonian catchments: application of rainfall–runoff models to simulate flow duration curves. Hydrological Sciences Journal, 58 (7), 1–11.

Simulation and optimization of thrust circular bearings with planes sector-shaped

Purpose – The purpose of this paper is to analyze journal thrust bearings geometries, used in household refrigerators, using a modified version of the Reynolds equation which includes the inertial terms. Design/methodology/approach – The Reynolds equation was solved through the finite volume method, thus providing the pressure field in the lubricant film and, consequently, the load and the power used by the bearing. Such parameters depend on bearing geometry, which was optimized through the method of Lagrange multipliers, to support a given load and use the lowest power possible. The optimized geometries included the Rayleigh pad with 4, 8 and 16 steps, and a milled geometry with 4 steps. Findings – For the Rayleigh pad, the number of steps was varied and a decrease in the power consumed with the increase in the number of steps was observed. The milled pad performance was better than that Rayleigh pad with 4 steps and comparable to the pad with 8 steps. Originality/value – The manufacture of pads, with a ...

Influência da Variabilidade Climática sobre a Erosividade em Belém (PA)

The Universal Soil Loss Equation (USLE) is a model in which soil loss is the product of several indices, including rainfall erosivity (R). This factor identifies when the greatest risk of water erosion occurs. The objective of this study was to analyze the influence of ENOS (El Niño Southern Oscillation) and Atlantic Dipole on the R factor in Belém (PA). Erosivities from 1986 to 2015 were classified according to intensity. ENSO events were also classified to evaluate a possible influence of their amplitude. The Niño Oscillation Index (ION) was used to verify the occurrence of ENSO. In order to analyze the Atlantic Dipole, the TNA (Tropical Northern Atlantic) and TSA (Tropical Southern Atlantic) indices were used, because this phenomenon directly interferes in the region’s main atmospheric system, the Intertropical Convergence Zone (ZCIT). Pearson correlation analysis and linear regression were determined between R and climatic indexes. Thus, lower erosivities were observed in years of intense El Niño, obtaining higher correlation coefficients. Coincidence of intense La Niña with Negative Dipole also represented higher correlation coefficients, meaning the increase of erosivity. There was a weak correlation of erosivity during Positive Dipole.

Proposal of rainwater harvesting coefficient (RWHC) for determination of effectively usable rainfall depth, relevant to rainwater harvesting systems design

The study measures rainfall data to determine a rainwater harvesting coefficient revelant to rainwater harvesting and catchment projects assisted by non-parametric statistics tests, based on assumption that part of the total rainfall depth is discarded. The analyses of historical rainfall series shows that the city of Belem presents large potential to promote rainwater harvesting, with a rainy season and a less rainy season during the year. The results present an average of one rainfall event per day, from January 2001 to December 2011, and of which around 38% is used only for washing the rainwater harvesting system. The Anderson-Darling test revealed a non-adherence of the rainfall series to a normal distribution and according to the Mann-Kendall test, there was no significant trend in the evaluated series. After the calculation of the effective rainfall, determination of coefficients, application of the Anderson-Darling normality test and the Kruskal-Wallis variance test, it was proposed a rainwater harvesting coefficient of 0.78 for the city of Belém, Brasil.