Groundwater quality comparison between rural farms and riparian wells in the western Amazon, Brazil

Leite, Nei Kavaguichi; Krusche, Alex V.; Cabianchi, Giovana Mendonça; Ballester, Maria Victória Ramos; Victória, Reynaldo Luiz; Marchetto, Margarida; Santos, J. G.

doi:10.1590/s0100-40422011000100003

Cited by 7 publications

(6 citation statements)

References 24 publications

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“…These values are in the range of the observations made in previous works (0.04-2.8 mgN-NO3.L -1 ; McClain et al, 1994;Leite et al, 2011). Concerning the Garonne basin, the SWAT model simulated average nitrate concentrations of 8.6 ± 5.8 mgN-NO3.L -1 in aquifers while past research measured concentrations between 3.86 and 17.95 mgN-NO3.L -1 (Jégo et al, 2012;Sun et al, 2018).…”

Section: Temporal and Spatial Validity Of The Resulting Floodplains Denitrification Ratessupporting

confidence: 77%

Daily denitrification rates in floodplains under contrasting pedo-climatic and anthropogenic contexts: modelling at the watershed scale

et al. 2020

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Floodplains play a crucial role in water quality regulation via denitrification. This biogeochemical process reduces nitrate (NO3 -), with aquifer saturation, organic carbon (OC) and N availability as the main drivers. To accurately describe the denitrification in the floodplain, it is necessary to better understand nitrate fluxes that reach these natural bioreactors and the transformation that occurs in these surface areas at the watershed scale.At this scale, several approaches tried to simulate denitrification contribution to nitrogen dynamics in study sites. However, these studies did not consider OC fluxes influences, hydrological dynamics and temperature variations at a daily time step. This paper focuses on a new model that allows insights on nitrate, OC, discharge and temperature influences on daily denitrification for each water body. We used a process-based deterministic model to estimate daily alluvial denitrification in different watersheds showing various pedo-climatic conditions.To better understand global alluvial denitrification variability, we applied the method to three contrasting catchments: The Amazon for tropical zones, the Garonne as representative of the temperate climate and the Yenisei for cold rivers. The Amazon with a high discharge, frequent 2 flooding and warm temperature, leads to aquifers saturation, and stable OC concentrations.Those conditions favour a significant loss of N by denitrification. In the Garonne River, the low OC delivery limits the denitrification process. While Arctic rivers have high OC exports, the low nitrate concentrations and cold temperature in the Yenisei River hinder denitrification. We found daily alluvial denitrification rates of 119.4 ± 47.5, 7.6 ± 5.4 and 0.1 ± 0.5 kgN.ha -1 .yr -1 during the 2000-2010 period for the Amazon, the Garonne and the Yenisei respectively. This study quantifies the floodplains influence in the water quality regulation service, their contribution to rivers geochemical processes facing global changes and their role on nitrate and OC fluxes to the oceans.

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Section: Temporal and Spatial Validity Of The Resulting Floodplains Denitrification Ratessupporting

confidence: 77%

Daily denitrification rates in floodplains under contrasting pedo-climatic and anthropogenic contexts: modelling at the watershed scale

et al. 2020

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“…A faixa de valores apresentados expressa ser de baixa salinidade a água dos poços, conforme define o autor citado. Leite et al (2010) explica que os ecossistemas florestais da região amazônica, pouco antropizados, apresentam baixos valores de condutividade e reforça que valores mais elevados de condutividade estão associados a áreas onde predominam atividades agrícolas, semelhante a área estudada em que os maiores valores de CE foram observados nos poços próximo à horta. Os valores de nitrato (NO 3 -) nos pontos estudados variaram entre 3,4 a 15,1, com média de 9,36 mg/L, ao período chuvoso.…”

Section: Qualidade Da áGua Subterrâneaunclassified

Comprometimento Da Qualidade Da Água Subterrânea Por Nitratos

Nunes

Gomes

Webler

et al. 2012

Nucleus

Self Cite

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Uma parcela considerável da população de Ji-Paraná supre suas necessidades diárias de água em sistemas alternativos de abastecimento, com água proveniente do manancial subterrâneo. Estudos evidenciam que este recurso é suscetível à contaminação e/ou poluição por fontes de poluição pontual, como as fossas, amplamente utilizadas na área urbana deste município. Áreas de plantio de hortaliças são potenciais fontes difusas de contaminação da água e informações sobre o seu efeito na qualidade da água subterrânea ainda são incipientes. Sendo assim, esse estudo propõe avaliar a qualidade da água em localidades próximas a horta, na cidade de Ji-Paraná -RO, a fim de elucidar o impacto que as práticas de fertilização têm na qualidade da água. Desta forma, avaliou-se as concentrações dos íons nitrato e nitrito, além dos parâmetros pH, condutividade elétrica e oxigênio dissolvido, nos períodos de maior e menor precipitação. Ao analisar os resultados da pesquisa, comparando os pontos amostrais à montante e próximos à horta, percebe-se que as maiores concentrações de nitratos quanto de nitrito ocorrem nos pontos adjacentes à área de cultivo. As maiores concentrações para ambos os parâmetros ocorrem na estação seca, valores médios superiores ao período chuvoso em 52,77% para o nitrato e 158,86% para o nitrito. Quanto aos demais parâmetros, não há uma correlação clara entre área de plantio de hortaliças e seus valores.

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“…Analyzing data of 10 small watersheds throughout the Amazon, Neill et al [29] concluded that the contribution of overland flow as a source of stream flow was greater in pasture watersheds than in forest watersheds of comparable size. Large pasture areas, with narrow or nonexistent riparian forests, can alter the chemical composition of rivers, particularly for streamwater cation concentrations and alkalinity [30,31]. As a result of increased root and microbial respiration during the wet season, generated CO 2 in soils drives cation-bicarbonate leaching from the landscape to streams and stream water.…”

Section: Watershed Biogeochemistry Affected By Large Crops and Pasturementioning

confidence: 99%

“…As a result of increased root and microbial respiration during the wet season, generated CO 2 in soils drives cation-bicarbonate leaching from the landscape to streams and stream water. It is assumed that cations (derived from ashes of forest burning for pasture conversion) and bicarbonates are mainly flushed from surface soil layers by rainfall rather than as the products of deep soil weathering carried by groundwater, with cation concentrations increasing during larger discharge periods [30,31].…”

Section: Watershed Biogeochemistry Affected By Large Crops and Pasturementioning

confidence: 99%

Agricultural Impacts on Hydrobiogeochemical Cycling in the Amazon: Is There Any Solution?

Figueiredo

Cak

Markewitz

2020

Water

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Expansion of agriculture in the Brazilian Amazon has been driven not just by demands from traditional, rural producers, but also large agriculture and cattle producers, both of whom have put considerable pressure on remaining forests and their watersheds. Monitoring of these watersheds has been a focus of intensive study for the past 20 years and although this work has greatly increased our understanding, considerable gaps still remain in our ability to provide adequate recommendations for land management and associated public policies. In this study we present a summary of findings from these previous results. For small properties, the use of fire to prepare land for cultivation remains controversial, while in large properties, forest conversion to pasture and/or crop production has had a meaningful and adverse effect on water quality. Riparian forest conservation can make a significant difference in reducing impacts of land-use change. Secondary vegetation can also play an important role in mitigating these impacts. New types of sustainable agricultural production systems, together with incentives such as payments for ecosystem service can also contribute. Continued monitoring of these changes, together with robust sustainable development plans, can help to preserve forest while still addressing the social and economic needs of Amazonian riverine inhabitants.

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Groundwater quality comparison between rural farms and riparian wells in the western Amazon, Brazil

Cited by 7 publications

References 24 publications

Daily denitrification rates in floodplains under contrasting pedo-climatic and anthropogenic contexts: modelling at the watershed scale

Daily denitrification rates in floodplains under contrasting pedo-climatic and anthropogenic contexts: modelling at the watershed scale

Comprometimento Da Qualidade Da Água Subterrânea Por Nitratos

Agricultural Impacts on Hydrobiogeochemical Cycling in the Amazon: Is There Any Solution?

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