Research
Water Resource Conflict in the Amazon Region: The Case of Hydropower Generation and Multiple Water uses in the Tocantins and Araguaia River Basins
The guarantee of multiple water use is one of the main objectives of the Brazilian system of managing water resources. However, it is still unclear how to reach these objectives regarding hydropower plants. This paper introduces a method for support of hydropower plants taking into account the compatibility with multiple water uses. It also introduces a computational tool based on the proposed method, which assesses energy generation and possible losses associated with meeting upstream water demand. A case study of the Tocantins and Araguaia basins (Amazon region) is presented. The results obtained corroborate the applicability of the proposed method.
Simulation of Floods with 1d And 2d Hydraulic Models in the GUAPI-AAU River Basin, Based on GIS Integration
With a focus on water sustainability, Fluminense Federal University developed the Macacu Project, which included the integrated management of water resources in the basin of the Guapi-Açu River. One component of the project was the simulation of the rivers’ flow patterns, supported by topographic and bathymetric surveys conducted in 2008. New surveying services were provided in 2012. From the data generated, new simulations with HEC-RAS (1D) and IBER (2D) models were performed by combining the use GIS. Hydrographs with return periods of 2, 10, 20 and 50 years were simulated and the results showed that areas potentially most affected by flooding are pasture and forest, but flooded spots were observed also in some constructed areas. The 2D model produced results more compatible with what would occur naturally in floodplains, but it requires a large amount of data and lengthy processing time.
Estimated Ecological Flow of the PRETO River by the Wetted Perimeter Method
The ecological flow is the minimum flow of a river necessary to maintain its aquatic fauna. In the present study, this flow was estimated for the Preto River, which belongs to the Piabanha River Basin, located in the state of Rio de Janeiro, Brazil. Because the Preto River’s entire length is within the state, its management is under the responsibility of the Rio de Janeiro State Environmental Institute (INEA). The INEA adopts the value of 50% of Q7,10 as the minimum ecological flow for rivers in the state. Hydrological data were obtained from a stage gauge located on the river, allowing estimation of the ecological flow. The results were satisfactory, because the two ecological flow values calculated were lower than the lowest flow observed during the historic discharge series of the river.
Comparison of Crisp and Fuzzy Logics on the Location of a Gauging Station
The traditional logic (crisp) is based on the dichotomy of true and false, what is not true is false and what is not false is true. Half term does not exist. However, the real world presents some situations where the answers true and false are not enough to represent the reality. Using this idea, it was applied, in this paper, the logics crisp and fuzzy to a problem of choose of place for the implantation of a gauge station in a watershed. COPPETEC-COSENZA model for crisp logic and operation with triangular numbers in electronic spread sheet (fuzzy) were adopted. The same results had been presented with regard to the adequateness to the implantation of the gauge station.
Sisvaznat: Natural Flows Reconstitution System as a Support for Water Resources Management
This paper presents a general system for the reconstitution of natural flows series to support the SNIRH (Brazilian acronym for National Water Resources Information System). There is a need for system structuring due to the fact that streamflows may suffer human modifications which difficult to carry out water resources management. In order to make a reliable assessment, it is essential to determine the socalled “natural flow series†i.e. the flows that would have occurred prior to human action. The SisVazNat system was applied in the Tocantins watershed, located in the Amazon Region, and in order to validate the proposed methodology, the results were compared with those published by the Electric System National Operator (ONS). The mean percent differences obtained in each hydropower plant were, respectively: UHE Serra da Mesa (3.2%); UHE Cana Brava (5.6%); UHE Lajeado (4.2%) and UHE Tucuruà (4.4%), allowing the validation of the tool.
