Gerson Cardoso da Silva Júnior

Water resource management: a comparative evaluation of Brazil, Rio de Janeiro, the European Union, and Portugal.

This paper presents an overview of water resource management in Brazil, in particular the state of Rio de Janeiro, and in the European Union, with an emphasis on member country Portugal. The study examines the primary laws, governing bodies and water resource plans. The paper describes the concerns and interests of the scientific community and other sectors of society with regard to water resource management. The paper also draws attention to challenges and opportunities concerning the main objective of water resource management, which is to ensure the availability of water of high quality and sustainable quantity. Additionally, it also mentions good and poor management practices. Among the concerns highlighted are integrated water resource management and water resource monitoring. The objective of this study was to contribute to water resource management processes. The primary reasons for this study are the growing scarcity of freshwater in the world, recurrent problems in managing this resource and a desire to contribute to the improvement of the current situation. The study of water management in different contexts allows for a greater understanding of the subject, thereby assisting the decision-making of managers and society in general with regard to environmental quality and ecological and human health. There is an increasing interest in efficient water resource management, which creates a demand for information on the subject. Both Brazil and the European Union are facing problems related to quantity and quality of water. Problems like scarcity of freshwater, contamination, salinization, and floods. This makes the realities of them quite close, despite the physical distance between them. In general, Brazil, Rio de Janeiro, the European Union and Portugal have similar water resource management requirements. If these regions are to supply a consistent quantity of high-quality water to present and future generations, then they need effective laws and plans, efficient managing agencies, political interest and economic resources. Investments in research and developing water resource management plans are inefficient measures if they are not implemented with special emphasis on monitoring and inspection.

Water quality and its spatial relation with sources of natural and human contamination: São Domingos river basin, Rio de Janeiro state, Brazil

The purpose of this article is the evaluation of Sao Domingos River Basin (SDRB) water quality and tentative correlations with natural and anthropic polluting sources. In order to achieve it, physicochemical parameters were analyzed in 65 surface and groundwater sampling points, in accordance to standards established by the Brazilian Environmental Authority, CONAMA 357/05, Class 2, for surface water and CONAMA 396/08, Class human, consumption for groundwater. The analyzed parameters include major cations and anions, temperature, pH, electric conductivity, total dissolved solids (TDS), alkalinity, dissolved oxygen (DO), biochemical oxygen demand (BOD), thermotolerant coliforms, organochlorides and organophosphorus compounds. Parameters with concentrations more frequently in unconformity with regulations are: aluminum, boron, iron, manganese, nitrates, DO, BOD and some organochlorides and organophosphorus compounds. Results show that distribution of contamination is strongly influenced by the human presence, such as rural and urban population and tomato culture. Natural aspects also play a major role, since availability of aluminum, iron, and manganese in near-surface waters in tropical environment depends on input from processes taking place in leaf litter and topsoil.

Aspectos Hidrodinâmicos, Balanço Hídrico e Simulação de Fluxo no Aquífero Costeiro de Itaipuaçu, Maricá - Rio de Janeiro, Brasil

This research was conducted in the coastal aquifer of Itaipuacu district, Marica, Rio de Janeiro in Brazil. This is an aquifer of great importance for the region, as it is still the only autochthonous means of water supply for a growing population. The use of this water resource without control is a big problem, because quality can be impaired by contamination coming from the surface and, as a coastal aquifer, overexploitation can generate migration of saltwater / freshwater interface towards mainland and can salinize it. The paper aims to present the hydrodynamic characteristics of the shallow aquifer of the study area, by assessing local flow, flow parameters of the aquifer, acquisition and processing of meteorological data and water balance of the aquifer system, with the application of Visual Balan V.2.0 code. Other calculation methodologies were employed, as hydrometeorological simplified balance (Easybal v.4 computer code) and water balance with use of Darcy’s Law. Wells were drilled in the shallow aquifer of the study area to assess local stratigraphy, and interference tests were performed to obtain physical parameters of the aquifer (permeability and storage coefficient). In situ measurements of water levels in wells were performed in the region to map the shallow aquifer head distribution. The data indicate a low hydraulic gradient and equipotential lines subparallel to the shoreline. Based on the hydraulic parameters, flow simulations were performed with the software Visual Modflow 4.2. The results obtained to date indicate a recharge of about 36% of the precipitation and hydraulic gradient less than 1%. Obtaining in situ parameters of the aquifer was crucial for the proper model fit and evaluation of the local aquifer properties.