Rachel Bardy Prado

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.

Priority areas for watershed service conservation in the Guapi-Macacu region of Rio de Janeiro, Atlantic Forest, Brazil

IntroductionLand use intensification and urbanisation processes are degrading hydrological ecosystem services in the Guapi-Macacu watershed of Rio de Janeiro. A proposal to pay farmers to restore natural watershed services might be an alternative to securing the water supply in the long-term for the around 2.5 million urban water users in the study region. This study quantifies the costs of changing current land use patterns to enhance watershed services and compares these costs to the avoided costs associated with water treatment for public supply.MethodsWe use farm-household data to estimate the opportunity costs of abandoning current land uses for the recovery of natural vegetation; a process that is very likely to improve water quality in terms of turbidity due to reduced inputs from erosion. Opportunity cost estimates are extrapolated to the watershed scale based on remote sensing land use classifications and vulnerability analysis to identify priority zones for watershed management interventions. To assess the potential demand for watershed services, we analyse water quality and treatment cost data from the main local water treatment plant.ResultsChanging agricultural land uses for watershed services provision generally comes at high opportunity costs in our study area near to the metropolis of Rio de Janeiro. Alternative low cost watershed conservation options do exist in the livestock production sector. These options have the potential to directly reduce the amount of sediments and nutrients reaching the water bodies, and in turn decrease the costs of treatment needed for drinking water. Land cover changes at the scale needed to improve water quality will, nonetheless, likely exceed the cost of additional investments in water treatment.ConclusionsThe state water utility companys willingness to pay for watershed services alone will not be enough to induce provision of additional watershed services. We conclude that monetary incentives conditioned on specific adjustments to existing production systems could still have a complementary role to play in improving watershed services. However, we note that our willingness to pay analysis focusses on only one of the potentially wide range of ecosystem services provided by natural vegetation in the Guapi-Macacu watershed. Factoring these ecosystem services into the willingness to pay equation is likely to change our assessment in favour of additional conservation action, be it through PES or other policy instruments.

Evaluating the Potential of Landscape Metrics in Supporting Landscape Planning in Atlantic Forest: Rio de Janeiro, Brazil

The landscapes are highly dependent on the dynamics of local land use and land cover, which directly affects landscape structure and determines the spatial patterns of forest patches, as well as to the major land uses within a specific region. The calculation of landscape metrics can support the understanding of such spatial distribution. In this study, 16 landscape metrics were analyzed in a drainage watershed in a high relief region in the Rio de Janeiro state, Southeastern Brazil, with the aim to evaluate the use of landscape metrics as indicators for agricultural management. Metrics calculation was followed by a Principal Component Analysis, which indicated the metrics that were most effective in evidencing the landscape structure in analysis. The results showed that the late-succession forest is the dominant component in the landscape. This class also presented the highest MPS metric value, related to the mean patch size by class. Some PCA results suggest that the metrics association was less effective in clustering the overgrown pasture, clean pasture, and annual crops classes, but this could result from the intrinsic association among those classes, by crop rotation, meaning the abandon of a site formerly occupied by an annual crop. Some metrics better suggested an interaction among land use classes and have potential to be use in the analyses of agricultural landscapes in high relief sites.

Uma abordagem para avaliar o potencial de agroecossistemas em prover serviços ambientais

The objective of this work was to present an approach to evaluate soil functions in agroecosystems and their impact on environmental services (ES). An approach with case studies was proposed to assess the relationship between the establishment and management of agroecosystems, in three Brazilian biomes (Atlantic Forest, Cerrado, and Caatinga), and their environmental services provision, considering the specificities of each area. A set of soil parameters that can be used as indicators to monitor changes in the agroecosystem was also proposed. The environmental services types most affected by the establishment and management of the agroecosystems were the supporting and provisioning services, showing the potential of agricultural management in providing multiple services, besides food, fiber, and energy. “No fire use” and “agricultural consortium” were the criteria for the establishment and management of agroecosystems with greater potential to increase environmental services provision, whereas biomass stock in soil and litter was the most appropriate soil parameter to be used as an indicator to monitor the impact of agroecosystems in environmental services provision.

Avaliação espaço-temporal da relação entre o estado trófico do reservatório de Barra Bonita (SP) e o potencial poluidor de sua bacia hidrográfica

Esta pesquisa foi proposta devido ao processo de acelerada degradacao da qualidade da agua em regioes bastante populosas, o qual resulta, em grande parte, do uso e ocupacao da terra inadequados. Assim sendo, este objetiva avaliar a relacao entre o estado trofico do reservatorio de Barra Bonita (SP) e o potencial poluidor da bacia hidrografica de contribuicao no espaco e no tempo. A determinacao do estado trofico do reservatorio de Barra Bonita baseou-se em amostras coletados em 30 estacoes distribuidas homogeneamente na superficie do lago em duas datas: 1990 e 2002. Com base nessas amostras foram determinados os parâmetros necessarios a aplicacao do Indice de Estado Trofico (IET), cujos resultados foram espacializados utilizando-se o ArcView 3.2 da ESRI. Para determinar o potencial poluidor da bacia foram obtidas imagens do satelite Landsat referentes tambem a 1990 e 2002. Essas imagens foram submetidas a classificacao (dizer o tipo) de modo a se obter mapas de uso e cobertura da terra. Foram tambem obtidos dados sobre o crescimento populacional da bacia e dados para o calculo da carga de nitrogenio e fosforo lancada pela populacao, via esgoto sanitario, nos corpos hidricos da bacia. Os resultados mostraram que ocorreu um incremento significativo do nivel trofico da agua, entre 1990 e 2002 de forma diferenciada para cada compartimento do reservatorio em questao. A degradacao da qualidade da agua, expressa pelo nivel trofico foi muito mais intensa no braco do rio Tiete, cujos pontos apresentaram como eutroficos tanto em 1990 como para 2002 devido a contribuicao de fontes de poluicao da cidade de Sao Paulo. A avaliacao integrada dos sistemas aquatico e terrestre, no espaco e no tempo, permitiu concluir que a degradacao da qualidade da agua possui forte relacao com as alteracoes no uso e cobertura da terra e com o aumento populacional, traduzidos em fontes difusas e pontuais de poluicao e que estas alteracoes podem ser detectadas aplicando-se geotecnologias. Outro aspecto relevante dos resultados foi o de verificar que o potencial poluidor da bacia hidrografica nao e espacialmente homogeneo, e que portanto, as medidas de controle de poluicao precisam ser focadas nas areas mais criticas, onde a degradacao e mais intensa.

Development, validation, and application of a method for selected avermectin determination in rural waters using high performance liquid chromatography and fluorescence detection.

Avermectins (AVM) are macrocyclic lactones used in livestock and agriculture. A quantitative method of high performance liquid chromatography with fluorescence detection for the determination of eprinomectin, abamectin, doramectin and ivermectin in rural water samples was developed and validated. The method was employed to study samples collected in the Pito Aceso River microbasin, located in the Bom Jardim municipality, Rio de Janeiro State, Brazil. Samples were extracted by solid phase extraction using a polymeric stationary phase, the eluted fraction was re-concentrated under a gentle N2 flow and derivatized to allow AVM determination using liquid chromatography with fluorescence detection. The excitation and emission wavelengths of the derivatives were 365 and 470nm, respectively, and a total chromatographic run of 12min was achieved. Very low limits of quantification (22-58ngL(-1)) were found after re-concentration using N2. Recovery values varied from 85.7% to 119.2% with standard deviations between 1.2% and 10.2%. The validated method was applied in the determination of AVM in 15 water samples collected in the Pito Aceso River microbasin, but most of them were free of AVM or showed only trace levels of these compounds, except for a sample that contained doramectin (9.11µgL(-1)). The method is suitable for routine analysis with satisfactory recovery, sensitivity, and selectivity.

Soil and Water Management for Ecosystem Services Provision in Agricultural Landscapes: The Challenge of Monitoring

Soil and water conservation management includes practices that help to preserve the quality of soil, water, and biodiversity, to promote sustainable agriculture and to provide ecosystem services (ES). In the state of Rio de Janeiro, some agriculture conservation practices such as minimal tillage, crop rotation, agroforestry systems, rotational grazing, and fallow can contribute to value and provide ES and also increase productivity and income of the family farmers. However, it is necessary to identify the impacts of these practices on the provision of ES, and monitoring is an important means of analysis. This chapter presents a review of studies on the conservation management practices in the state of Rio de Janeiro and their impacts on ES. Moreover, it highlights aspects to be considered in monitoring of ecosystem service indicators. The main challenges of the monitoring approach include participatory efforts and multidisciplinary criteria used at appropriate scales in order to provide adequate and useful answers to society.

A Tool to Assess Land Use Impacts on Surface Water Quality: Case Study from the Guapi-Macacu River Basin in Rio de Janeiro

Impacts of human activities, mainly land use and land cover (LULC) changes, on hydrology and water quality are manifold and need to be ascertained. In order to understand and assess such impacts, water quality monitoring programs are crucial for collecting the required data. Transforming data into information is an important step, and water quality indices (WQIs) can be a useful and concise method for aggregating several parameters and measurements into a single number to facilitate problem identification and decision-making. For this study, a monitoring program was designed and implemented to measure water quality in a rural river basin in Rio de Janeiro (Guapi-Macacu). Three sub-watersheds, together with other relevant sampling points, were selected to assess the influence of the most relevant LULC classes on water quality. The monitored parameters were used to calculate the Canadian water quality index (CCME-WQI). This index was able to capture the impacts of water quality impairments such as untreated sewage and agricultural activities. The index calculation and resultant map, used to depict the spatial distribution, aim at becoming tools for practitioners and decision-makers in the basin.

Comparison Between the Water Quality Indexes Cetesb and Bascarán Applied to the Hydrographic Basin of the São Domingos River, Northwest of Rio de Janeiro

A agua e um bem essencial a vida e para muitas atividades economicas. Contudo, sua degradacao ocorre de forma acelerada, tornando-a inutilizavel para os multiplos usos da sociedade. Os municipios fluminenses de Sao Jose de Uba e Itaperuna abrigam a bacia hidrografica do rio Sao Domingos (BHRSD) no Rio de Janeiro, que apresenta elevados indices de desflorestamento, presenca extensiva de agropecuaria, centros urbanos com baixos indices de saneamento basico e intensiva extracao de agua subterrânea para uso domestico e irrigacao. Diante dessa situacao, o presente trabalho tem como objetivo analisar a qualidade da agua superficial da BHRSD a partir de dois Indices de Qualidade de Agua (IQA): o IQACETESB e o IQABASCARAN. Para tal, amostras de aguas superficiais foram obtidas em 19 pontos da bacia nos anos de 2004 e 2005. Os parâmetros avaliados e utilizados para compor os indices foram: oxigenio dissolvido, coliformes termotolerantes, pH, demanda bioquimica de oxigenio, nitrato, fosfato, turbidez, temperatura, solidos totais e aspecto visual da agua. Os resultados da aplicacao dos indices foram espacializados para a area da BHRSD. O indice da Cetesb apresentou resultados mais positivos, na maioria das amostras, a agua foi classificada como “Boa”. Enquanto que, pelo indice de Bascaran, a qualidade da agua da BHRSD apresentou pior qualidade, com amostras predominantemente classificadas como “Media” e “Ruim” e, em menor numero, como “Muito Ruim”. Quando nao aplicada a constante K presente no IQABASCARAN, os resultados desse indice apresentaramse similares ao do IQACETESB. Ja quando utilizada esta constante, as classificacoes foram mais distintas entre os indices. Os resultados gerais mostram que do ano de 2004 para 2005 a qualidade da agua piorou. Recomenda-se o IQABASCARAN para o monitoramento da qualidade da agua superficial nesta bacia por descrever mais severamente a qualidade da agua, garantindo, assim, maior seguranca hidrica a saude da populacao.