Groundwater/surface-water interaction is receiving increasing focus in Africa due to its importance to ecologic systems and sustainability. In South Africa’s 1998 National Water Act (NWA), water-use licenses, including groundwater, are granted only after defining the Reserve, the amount of water needed to supply basic human needs and preserve some ecological integrity. Accurate quantification of groundwater contributions to ecosystems for successful implementation of the NWA proves challenging; many of South Africa’s aquifers are in heterogeneous and anisotropic fractured-rock settings. This paper reviews the current conceptualizations and investigative approaches regarding groundwater/surface-water interactions in the context of South African policies. Some selected pitfall experiences are emphasized. The most common approach in South Africa is estimation of average annual fluxes at the scale of fourth-order catchments (∼500 km2) with baseflow separation techniques and then subtracting the groundwater discharge rate from the recharge rate. This approach might be a good start, but it ignores spatial and temporal variability, potentially missing local impacts associated with production-well placement. As South Africa’s NWA has already been emulated in many countries including Zambia, Zimbabwe and Kenya, the successes and failures of the South African experience dealing with the groundwater/surface-water interaction will be analyzed to guide future policy directions.

Entre os instrumentos da Política Nacional de Recursos Hídricos, a outorga de direito de uso dos recursos hídricos e o sistema de informações se destacam como os mais importantes. Enquanto a outorga visa assegurar o controle quantitativo e qualitativo das águas, o sistema de informações tem por objetivos: armazenar e divulgar informações sobre a situação qualitativa e quantitativa dos recursos hídricos; e atualizar permanentemente as informações sobre disponibilidade e demanda. A proposta de um sistema on-line para controle em tempo real dos usos múltiplos da água se traduz na operacionalização conjunta destes dois instrumentos. Confrontado a demanda por gerenciamento de grandes volumes de informação com a necessidade de análises espaciais complexas, uma nova era para a gestão de recursos hídricos torna-se possível com os avanços da hidrologia e a integração dos Sistemas de Informação Geográfica - SIG com a Tecnologia da Informação e Comunicação TIC. Neste contexto, o desenvolvimento do SIGWeb AQUORA aliou os avanços da hidrologia, do geoprocessamento e da gestão da informação com o objetivo de criar um sistema fundamentado na democratização da informação, na unificação dos cadastros de usuários e na automação dos processos de outorga, respeitando os critérios definidos por cada órgão gestor. Inicialmente aplicado à bacia do rio Doce, com 83.400 km2 e três dominialidades de gestão, o trabalho foi dividido em quatro etapas: a) construção da base de dados geográficos; b) regionalização de vazões características considerando a variabilidade do regime hidrológico; c) modelagem do banco de dados para gestão dos usos múltiplos da água; e d) desenvolvimento e avaliação da aplicação SIG na Web. A base geográfica foi construída a partir do Modelo Digital de Elevação Hidrograficamente Consistente (MDEHC) e operações matriciais e espaciais envolvendo regras topológicas e redes geométricas. Após consistidas as séries históricas de 61 estações fluviométricas da bacia do rio Doce, foram ajustadas equações de regressão para as regiões hidrologicamente homogêneas e, em seguida, as vazões características sazonais foram espacializadas e ajustadas utilizando as estações como pontos de controle. O modelo de geodatabase Arc Hydro foi reformulado para adequar-se às rotinas operacionais das entidades reguladoras. O sistema cliente-servidor utiliza o SGBDR OracleXE® e o gerenciador espacial ESRI® ArcGIS Server 9.3.1. As rotinas automatizadas para análise espacial dos processos de outorga e atualização da disponibilidade hídrica foram desenvolvidas com o Web ADF para Java no Eclipse IDE. Como resultado, a base de informações geográficas caracteriza as relações espaciais entre as microbacias e a rede de drenagem, possibilitando a navegação a jusante e a montante. A base de informações hidrológicas incorporou a sazonalidade da disponibilidade hídrica às vazões de referência, flexibilizando a disponibilidade outorgável nos períodos seco, normal e chuvoso. O modelo do banco de dados garante a versatilidade do sistema de informações, pois além de permitir análises espaciais e estudos hidrológicos com o auxílio de SIG, realiza a gestão administrativa dos processos de outorga e ainda serve de base para a aplicação na internet, disponível no endereço: http://agua.dea.ufv.br/Aquora. Com as funcionalidades de consulta, cadastro de usuários, solicitação de outorga e controle dos processos, o SIGWeb AQUORA não só tem a capacidade de gerenciar os processos administrativos relativos à outorga e divulgar informações hidrológicas na Internet, mas também analisa o impacto de captações superficiais e de lançamentos de efluentes, atualizando, em tempo real a disponibilidade hídrica em toda a hidrografia. Assim, o sistema constitui uma valiosa ferramenta de gestão para harmonizar a gestão entre as agências reguladoras, padronizar as rotinas operacionais, agilizar os pareceres técnicos e ampliar a participação da sociedade na gestão dos recursos hídricos. | Among the instruments of the National Policy of Water Resources, established in Brazil in 1997, the water rights of use and information system stand out as the most important. While the permits for water rights and withdrawal work to ensure the quantitative and qualitative control and the effective rights of access, the information system aims to: collect, validate and distribute information about water resources conditions, and continuously update data about water availability and demand. Faced with the increased demand for managing large volumes of information and the need for complex spatial analysis, a new hydrology combined with Information Technology (IT) provides the integration of Geographic Information Systems (GIS) and Relational Database Management System (RDBMS) functionality, through online platforms for the management of concurrent uses of water. In this context, the development of the multi-user system was based on designing a model and loading the essential hydrological and administrative information for water resources management in a simple, online geodatabase. This geodatabase is available through a Web Service with specific routines to analyze permits processes and permanently update the water availability in river systems. Initially applied to the river Doce basin, with 83,400 skm and located in southeastern Brazil, the work was divided into four stages: a) construction of the geographic datasets; b) regionalization of seasonal streamflow and accurate GIS spatial interpolation; c)) geodatabase design and loading hydrological and administrative data and information; d) development and evaluation of the GisWeb Service. After validating streamflow records of 61 gauged stations, the average, low and high flows were regionalized with regression equations applied to hydrologic homogeneous regions. The ArcHydro Data Model was reshaped for a geodatabase designed on water management laws and operational routines from environmental agencies that permit multiple uses of water. The multi-user system called SIGWeb AQUORA uses the RDBMS Oracle® XE and the ESRI® ArcGIS 9.3 Server and manager. The automated routines for spatial analysis of procedures for granting and updating water availability have been developed with the Web ADF for Java in Eclipse IDE. As a result, the base of geographic information characterizes the spatial relationships between watershed and drainage network, allowing the upstream and downstream navigation. The hydrological database incorporated the seasonality of low stream flows to the criteria for licensing through flexible bestowable availability during the diferent periods: dry, normal and wet. The format of the database ensures the versatility of the system information, as well as allows spatial analysis and hydrologic studies with GIS, performs the administrative procedures for granting water rights and still serves as the basis for the application on the Internet, available at address: http://agua.dea.ufv.br/Aquora. With the functionalities for user registration, requests for water rights and processes control, the SIGWeb AQUORA, not only has the capability of managing the administrative procedures for the permits and provide hydrological information on the Internet, but also provides the analysis of water withdrawal or discharge impacts, updating water availability throughout the river system. Thus, the AQUORA is a potential water management tool, able to standardize operating routines and expand the society participation on the integrated water management in Brazil. | Conselho Nacional de Desenvolvimento Científico e Tecnológico

Water quality monitoring is used to determine the impact of human activities on the environment. We evaluated water quality in the Água Boa stream, located within the municipality of Dourados, State of Mato Grosso do Sul, Brazil, by analyzing physico-chemical, chemical, and microbiological parameters, as well as chlorophyll concentrations. Five sets of water samples were collected between December 2012 and November 2013 from three locations within the stream. The results showed the presence of Escherichia coli and antibiotic-resistant Pseudomonas spp. strains and high concentrations of organic matter (total dissolved solids), inorganic species (Mg, Ca, and Fe), and agrochemical residues (thiamethoxam). The main stream water contaminants are derived from urban, industrial, and agricultural activities within the watershed. Given the presence of contaminants, it is important that such findings are disseminated in order to highlight the risks that contact with this water may pose to human health. To preserve the environment and improve site conditions, people would need to participate by demanding that normative national and international standards be respected and that the situation be supervised by the competent governmental agencies; this would make it possible to reverse or minimize contamination problems within the Água Boa stream.