Sedimentary metals in developing tropical watersheds in relation to their urbanization intensities

2021 ◽  
Vol 278 ◽  
pp. 111521
Author(s):  
Natchaya Namngam ◽  
Wenchao Xue ◽  
Xun Liu ◽  
Thammarat Kootattep ◽  
Rajendra P. Shrestha ◽  
...  
Keyword(s):  
2007 ◽  
Vol 64 (4) ◽  
pp. 317-324 ◽  
Author(s):  
Daniela Mariano Lopes da Silva ◽  
Jean Pierre Henry Balbaud Ometto ◽  
Gré de Araújo Lobo ◽  
Walter de Paula Lima ◽  
Marcos Augusto Scaranello ◽  
...  

Several studies in tropical watersheds have evaluated the impact of urbanization and agricultural practices on water quality. In Brazil, savannas (known regionally as Cerrados) represent 23% of the country's surface, representing an important share to the national primary growth product, especially due to intense agriculture. The purpose of this study is to present a comprehensive evaluation, on a yearly basis, of carbon, nitrogen and major ion fluxes in streams crossing areas under different land use (natural vegetation, sugar cane and eucalyptus) in a savanna region of SE Brazil. Eucalyptus and sugar cane alter the transport of the investigated elements in small watersheds. The highest concentration of all parameters (abiotic parameters, ions, dissolved organic carbon DOC - and dissolved inorganic carbon - DIC) were found in Sugar Cane Watersheds (SCW). The observed concentrations of major cations in Eucalyptus Watersheds (EW) (Mg, Ca, K, Na), as well as DIN and DOC, were found frequently to be intermediate values between those of Savanna Watersheds (SW) and SCW, suggesting a moderate impact of eucalyptus plantations on the streamwater. Same trends were found in relation to ion and nutrient fluxes, where the higher values corresponded to SCW. It is suggested that sugar cane plantations might be playing an important role in altering the chemistry of water bodies.


2016 ◽  
Vol 52 (11) ◽  
pp. 8895-8919 ◽  
Author(s):  
Yannis G. Dialynas ◽  
Satish Bastola ◽  
Rafael L. Bras ◽  
Erika Marin-Spiotta ◽  
Whendee L. Silver ◽  
...  

2011 ◽  
Vol 77 (12) ◽  
pp. 3988-3997 ◽  
Author(s):  
Dustin K. Goto ◽  
Tao Yan

ABSTRACTHigh levels ofEscherichia coliwere frequently detected in tropical soils in Hawaii, which present important environmental sources ofE. colito water bodies. This study systematically examinedE. coliisolates from water and soil of several watersheds in Hawaii and observed high overall genotypic diversity (35.5% unique genotypes). In the Manoa watershed, fewer than 9.3% of the observedE. coligenotypes in water and 6.6% in soil were shared between different sampling sites, suggesting the lack of dominant fecal sources in the watershed. High temporal variability ofE. coligenotypes in soil was also observed, which suggests a dynamicE. colipopulation corresponding with the frequently observed high concentrations in tropical soils. WhenE. coligenotypes detected from the same sampling events were compared, limited sharing between the soil and water samples was observed in the majority of comparisons (73.5%). However, several comparisons reported up to 33.3% overlap ofE. coligenotypes between soil and water, illustrating the potential for soil-water interactions under favorable environmental conditions. In addition, genotype accumulation curves forE. colifrom water and soil indicated that the sampling efforts in the Manoa watershed could not exhaust the overall genotypic diversity. Comparisons ofE. coligenotypes from other watersheds on Oahu, Hawaii, identified no apparent grouping according to sampling locations. The results of the present study demonstrate the complexity of usingE. colias a fecal indicator bacterium in tropical watersheds and highlight the need to differentiate environmental sources ofE. colifrom fecal sources in water quality monitoring.


Author(s):  
Andréia da Paz Schiller ◽  
Michelli Caroline Ferronato ◽  
Daniel Schwantes ◽  
Affonso Celso Gonçalves Jr ◽  
Deoclécio José Barilli ◽  
...  

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