cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.7506560
title: Analysis of the role of the sanitary landfill in waste management strategies based upon a review of lab leaching tests and new tools to evaluate leachate production

description: Abstract This paper reviews the role of sanitary landfills in current and future waste management strategies based upon the principles and the goals established by the European Framework Directive on Waste (2008/98/EC). Specific reference is made to studies of our research group regarding new tools developed to evaluate leachate production, taking into account the different characteristics of municipal solid waste (MSW). Laboratory leaching tests and a methodology proposed to interpret the results are described and discussed, as well as tools developed to estimate landfill leachate production. Residual flows produced by mechanical-biological treatment (MBT) plants, mainly Solid Recovered Fuel (SRF) and Stabilized Organic Waste (SOW), incineration and composting plants are considered in particular. Experimental results showed that the most suitable end-uses or disposal options for the outputs of waste treatment plants are site-specific and should be defined on the basis of a detailed characterization. The application of the model developed to assess landfill leachate production showed a very good agreement with field data.
DOI: 10.6084/m9.figshare.7506560.v1
title: Analysis of the role of the sanitary landfill in waste management strategies based upon a review of lab leaching tests and new tools to evaluate leachate production

description: Abstract This paper reviews the role of sanitary landfills in current and future waste management strategies based upon the principles and the goals established by the European Framework Directive on Waste (2008/98/EC). Specific reference is made to studies of our research group regarding new tools developed to evaluate leachate production, taking into account the different characteristics of municipal solid waste (MSW). Laboratory leaching tests and a methodology proposed to interpret the results are described and discussed, as well as tools developed to estimate landfill leachate production. Residual flows produced by mechanical-biological treatment (MBT) plants, mainly Solid Recovered Fuel (SRF) and Stabilized Organic Waste (SOW), incineration and composting plants are considered in particular. Experimental results showed that the most suitable end-uses or disposal options for the outputs of waste treatment plants are site-specific and should be defined on the basis of a detailed characterization. The application of the model developed to assess landfill leachate production showed a very good agreement with field data.
DOI: 10.6084/m9.figshare.7513400
title: Evasion of CO2 and dissolved carbon in river waters of three small catchments in an area occupied by small family farms in the eastern Amazon

description: Abstract CO2 effluxes from streams and rivers have been hypothesized to be a critical pathway of carbon flow from the biosphere back to the atmosphere. This study was conducted in three small Amazonian catchments to evaluate carbon evasion and dynamics, where land-use change has occurred on small family-farms. Monthly field campaigns were conducted from June 2006 to May 2007 in the Cumaru (CM), Pachibá (PB) and São João (SJ) streams. Electrical conductivity, pH, temperature, and dissolved oxygen measurements were done in situ, while water samples were collected to determine dissolved organic carbon (DOC) and dissolved inorganic carbon (DIC) concentrations, as well as carbon dioxide partial pressures (pCO2) and CO2 evasion fluxes. Instantaneous discharge measured by a current meter was used to calculate DOC fluxes. Considering all the sites, DOC, DIC, pCO2, and CO2 flux measurements ranged as follows, respectively: 0.27 - 12.13 mg L-1; 3.5 - 38.9 mg L-1; 2,265 - 26,974 ppm; and 3.39 - 75.35 μmol m-2 s-1. DOC annual flux estimates for CM, SJ and PB were, respectively, 281, 245, and 169 kg C ha-1. CO2 evasion fluxes had an average of 22.70 ± 1.67 μmol m-2 s-1. These CO2 evasion fluxes per unit area were similar to those measured for major Amazonian rivers, thus confirming our hypothesis that small streams can evade substantial quantities of CO2. As secondary vegetation is abundant as a result of family farming management in the region, we conclude that this vegetation can be a major driver of an abundant carbon cycle.
DOI: 10.6084/m9.figshare.7513400.v1
title: Evasion of CO2 and dissolved carbon in river waters of three small catchments in an area occupied by small family farms in the eastern Amazon

description: Abstract CO2 effluxes from streams and rivers have been hypothesized to be a critical pathway of carbon flow from the biosphere back to the atmosphere. This study was conducted in three small Amazonian catchments to evaluate carbon evasion and dynamics, where land-use change has occurred on small family-farms. Monthly field campaigns were conducted from June 2006 to May 2007 in the Cumaru (CM), Pachibá (PB) and São João (SJ) streams. Electrical conductivity, pH, temperature, and dissolved oxygen measurements were done in situ, while water samples were collected to determine dissolved organic carbon (DOC) and dissolved inorganic carbon (DIC) concentrations, as well as carbon dioxide partial pressures (pCO2) and CO2 evasion fluxes. Instantaneous discharge measured by a current meter was used to calculate DOC fluxes. Considering all the sites, DOC, DIC, pCO2, and CO2 flux measurements ranged as follows, respectively: 0.27 - 12.13 mg L-1; 3.5 - 38.9 mg L-1; 2,265 - 26,974 ppm; and 3.39 - 75.35 μmol m-2 s-1. DOC annual flux estimates for CM, SJ and PB were, respectively, 281, 245, and 169 kg C ha-1. CO2 evasion fluxes had an average of 22.70 ± 1.67 μmol m-2 s-1. These CO2 evasion fluxes per unit area were similar to those measured for major Amazonian rivers, thus confirming our hypothesis that small streams can evade substantial quantities of CO2. As secondary vegetation is abundant as a result of family farming management in the region, we conclude that this vegetation can be a major driver of an abundant carbon cycle.
DOI: 10.6084/m9.figshare.7516835
title: Daily rainfall disaggregation for Tocantins State, Brazil

description: ABSTRACT In order to design effective Brazilian hydraulic structures, it is necessary to obtain data relating to short-duration intense rainfall from historical series of daily rainfall. This recurring need can be fulfilled by rainfall disaggregation methodology. The objective of this study was to determine the intense rainfall disaggregation constants for the State of Tocantins and to compare these constants with those obtained for other regions of Brazil. For the modeling of the frequency of intense rainfall of different durations of less than 24 hours, the Gumbel probability distribution (GPD) was employed using rainfall series from 10 locations in Tocantins state. The results showed that the GPD was adequate by the Kolmogorov-Smirnov and Chi-square tests. The disaggregation constants presented low variability values for different return periods (from 10 to 100 years); the values for Tocantins state are: h12h/h24h=0.93, h6h/h24h=0.86, h4h/h24h=0.82, h3h/h24h=0.78, h2h/h24h=0.72, h1h/h24h=0.61, h50min/h1h=0.92, h40min/h1h=0.83, h30min/h1h=0.68, h20min/h30min=0.76 e h10min/h30min=0.46. The comparison of the results with those from studies developed for other Brazilian regions showed variations of up to -62.30%, allowing us to conclude that the use of local constants is important in the process of rainfall disaggregation.
DOI: 10.6084/m9.figshare.7516835.v1
title: Daily rainfall disaggregation for Tocantins State, Brazil

description: ABSTRACT In order to design effective Brazilian hydraulic structures, it is necessary to obtain data relating to short-duration intense rainfall from historical series of daily rainfall. This recurring need can be fulfilled by rainfall disaggregation methodology. The objective of this study was to determine the intense rainfall disaggregation constants for the State of Tocantins and to compare these constants with those obtained for other regions of Brazil. For the modeling of the frequency of intense rainfall of different durations of less than 24 hours, the Gumbel probability distribution (GPD) was employed using rainfall series from 10 locations in Tocantins state. The results showed that the GPD was adequate by the Kolmogorov-Smirnov and Chi-square tests. The disaggregation constants presented low variability values for different return periods (from 10 to 100 years); the values for Tocantins state are: h12h/h24h=0.93, h6h/h24h=0.86, h4h/h24h=0.82, h3h/h24h=0.78, h2h/h24h=0.72, h1h/h24h=0.61, h50min/h1h=0.92, h40min/h1h=0.83, h30min/h1h=0.68, h20min/h30min=0.76 e h10min/h30min=0.46. The comparison of the results with those from studies developed for other Brazilian regions showed variations of up to -62.30%, allowing us to conclude that the use of local constants is important in the process of rainfall disaggregation.
DOI: 10.6084/m9.figshare.7509953
title: Response of fish communities to intense drought in Brazilian savanna streams

description: Abstract The physical structures of streams are subjected to intense changes throughout the seasons. Intense drought in dry periods has been frequent and potentially harmful to aquatic species. In this study, we tested whether the changes in the habitat structure of the streams during the dry period determine the organization of fish communities. Five streams in the Upper Tocantins River were studied in the dry and rainy seasons. The species were characterized by 13 functional traits based on morphological measurements. The descriptors of functional diversity were: mean pairwise functional distance of species in the community (MPD) and mean functionally nearest species distance (MNTD). We also calculated the standardized effect size for MPD and MNTD, an indicator of functional redundancy, and compared the observed patterns with those expected by chance. Streams differed between seasons with respect to environmental variables. Functional diversity in the rainy season did not differ from the pattern expected by chance for both metrics. While functional diversity in the dry season has not differed from the pattern expected by chance for SESMPD, a greater functional redundancy for SESMNTD was found in this season. These results indicate that environmental changes in the streams during the dry season are important constraints for fish occurrence, preventing the occurrence of functionally original species. Therefore, a prospective scenario of dry-period intensification could result in functionally redundant communities, with functional homogenization of the regional species pool.
DOI: 10.6084/m9.figshare.7509953.v1
title: Response of fish communities to intense drought in Brazilian savanna streams

description: Abstract The physical structures of streams are subjected to intense changes throughout the seasons. Intense drought in dry periods has been frequent and potentially harmful to aquatic species. In this study, we tested whether the changes in the habitat structure of the streams during the dry period determine the organization of fish communities. Five streams in the Upper Tocantins River were studied in the dry and rainy seasons. The species were characterized by 13 functional traits based on morphological measurements. The descriptors of functional diversity were: mean pairwise functional distance of species in the community (MPD) and mean functionally nearest species distance (MNTD). We also calculated the standardized effect size for MPD and MNTD, an indicator of functional redundancy, and compared the observed patterns with those expected by chance. Streams differed between seasons with respect to environmental variables. Functional diversity in the rainy season did not differ from the pattern expected by chance for both metrics. While functional diversity in the dry season has not differed from the pattern expected by chance for SESMPD, a greater functional redundancy for SESMNTD was found in this season. These results indicate that environmental changes in the streams during the dry season are important constraints for fish occurrence, preventing the occurrence of functionally original species. Therefore, a prospective scenario of dry-period intensification could result in functionally redundant communities, with functional homogenization of the regional species pool.
DOI: 10.6084/m9.figshare.7517360.v1
title: Evaluation of water-stress tolerance of Acala SJ 2 and Auburn 2 cotton cultivars in a phenotyping platform

description: Abstract Due to the current scarcity of water, which may be aggravated by climate changes, it is important to develop cultivars tolerant to water stress. For this, information regarding the variability of the tolerance of cultivars to this stress is required. This information can be obtained by using phenotyping platforms, which allow a large-scale and automated assessment of crop traits related to productivity under water stress. This study took place in a greenhouse and used a phenotyping platform to evaluate some agronomic and physiological traits of two cotton cultivars with differing tolerances to this stress. The experiment was performed in a randomized block design, in a split-plot scheme with four replicates. The main plots were composed of five water regimes and the subplots of two cultivars, Acala SJ 2 and Auburn 2. The water regimes consisted of a well-irrigated treatment (daily replacement of 100% of evapotranspired water) and four water restriction regimes (20%, 40%, 60% and 80% of evapotranspired water at the well-irrigated treatment). The phenotyping platform and protocol (different percentages of daily replacement of evapotranspired water) employed were suitable to the evaluated cotton cultivars for water-stress tolerance, and allowed the determination of the cultivar most tolerant (Acala SJ 2) and of the cultivar most sensitive (Auburn 2) to water stress. ‘Acala SJ 2’ displayed better physiological and agronomic traits in all water regimes, including higher root density in the upper soil layer, as well as higher water use than ‘Auburn 2’, which explained its higher seed yield under the conditions employed.
DOI: 10.6084/m9.figshare.7517360
title: Evaluation of water-stress tolerance of Acala SJ 2 and Auburn 2 cotton cultivars in a phenotyping platform

description: Abstract Due to the current scarcity of water, which may be aggravated by climate changes, it is important to develop cultivars tolerant to water stress. For this, information regarding the variability of the tolerance of cultivars to this stress is required. This information can be obtained by using phenotyping platforms, which allow a large-scale and automated assessment of crop traits related to productivity under water stress. This study took place in a greenhouse and used a phenotyping platform to evaluate some agronomic and physiological traits of two cotton cultivars with differing tolerances to this stress. The experiment was performed in a randomized block design, in a split-plot scheme with four replicates. The main plots were composed of five water regimes and the subplots of two cultivars, Acala SJ 2 and Auburn 2. The water regimes consisted of a well-irrigated treatment (daily replacement of 100% of evapotranspired water) and four water restriction regimes (20%, 40%, 60% and 80% of evapotranspired water at the well-irrigated treatment). The phenotyping platform and protocol (different percentages of daily replacement of evapotranspired water) employed were suitable to the evaluated cotton cultivars for water-stress tolerance, and allowed the determination of the cultivar most tolerant (Acala SJ 2) and of the cultivar most sensitive (Auburn 2) to water stress. ‘Acala SJ 2’ displayed better physiological and agronomic traits in all water regimes, including higher root density in the upper soil layer, as well as higher water use than ‘Auburn 2’, which explained its higher seed yield under the conditions employed.
DOI: 10.6084/m9.figshare.7514843
title: Zoning of the hydrographic basin of Moju river (Pará): Water use and its relation with the forms of land cover and land use

description: Abstract The Moju River Basin presents different patterns of land use resulting from a historic expansion of the agricultural and extractive sector in the state. It is embedded in the area of developmental projects in the region, with emphasis on the palm oil productive chain. In the present work, a zoning of the Moju River Basin has been carried out, evidencing the interconnection between the land use and land cover and the water use, showing the pressures on the natural resources that the basin is undertaking. The zoning is a product resulting from the association between land use and land cover mapping, and the categories of water users of the municipalities that compound the basin. The results showed that the greatest water user grant has industrial purpose, with underground extraction massively than the superficial, where the palm oil industry has the highest water use grant. Only a small number of inhabitants are served by water distribution and there are high rates of loss in the distribution system. The Alto Moju sub-basin suffers high pressure on its natural resources. We noticed that the basin as a whole has most of its territory covered by forest, although pasture and secondary vegetation are also expressive. In general, we observed that the biggest challenge is to align the management of water resources and efficient land use.
DOI: 10.6084/m9.figshare.7514843.v1
title: Zoning of the hydrographic basin of Moju river (Pará): Water use and its relation with the forms of land cover and land use

description: Abstract The Moju River Basin presents different patterns of land use resulting from a historic expansion of the agricultural and extractive sector in the state. It is embedded in the area of developmental projects in the region, with emphasis on the palm oil productive chain. In the present work, a zoning of the Moju River Basin has been carried out, evidencing the interconnection between the land use and land cover and the water use, showing the pressures on the natural resources that the basin is undertaking. The zoning is a product resulting from the association between land use and land cover mapping, and the categories of water users of the municipalities that compound the basin. The results showed that the greatest water user grant has industrial purpose, with underground extraction massively than the superficial, where the palm oil industry has the highest water use grant. Only a small number of inhabitants are served by water distribution and there are high rates of loss in the distribution system. The Alto Moju sub-basin suffers high pressure on its natural resources. We noticed that the basin as a whole has most of its territory covered by forest, although pasture and secondary vegetation are also expressive. In general, we observed that the biggest challenge is to align the management of water resources and efficient land use.
DOI: 10.6084/m9.figshare.7516823
title: Comparative characterization of humic substances extracted from freshwater and peat of different apparent molecular sizes

description: Abstract This paper compares the structural characteristics of aquatic humic substances (AHS) with humic substances from peat (HSP) through different analytical techniques, including elemental analysis, solid state 13C cross polarization/magic-angle-spinning nuclear magnetic resonance spectroscopy (13C CP-MAS NMR), ultraviolet/visible (UV/Vis) spectroscopy and Fourier transform infrared (FTIR) spectroscopy and total organic carbon (TOC). The AHS were extracted from water collected in a tributary of the Itapanhaú River (Bertioga/SP) using XAD 8 resin, and the HSP were extracted from peat collected in the Mogi Guaçu River bank (Luis Antonio/SP) with a KOH solution. After dialysis, both AHS and HSP extracts were filtered in membrane of 0.45 µm pore size (Fraction F1: &lt; 0.45 µm) and fractioned by ultrafiltration in different apparent molecular sizes (AMS) (F2: 100 kDa-0.45 μm; F3: 30 kDa-100 kDa and F4: &lt; 30 kDa). The extracts with the lowest AMS (F3 and F4) showed a higher number of aliphatic carbons than aromatic carbons, a higher concentration of groups containing oxygen and a higher percentage of fulvic acids (FA) than humic acids (HA) for both AHS and HSP. However, the AHS presented higher FA than HA content in relation to the HSP and distinct structural properties.
DOI: 10.6084/m9.figshare.7512170
title: Space-time variability of evapotranspiration and precipitation in the State of Paraná, Brazil

description: Abstract Long-term changes in important weather variables such as evapotranspiration (ET) and precipitation are expected as a response to climate change. These changes may require adjustments to current strategies of planning and management of water resources. The objective of this work was to conduct a spatiotemporal characterization of evapotranspiration in the State of Paraná, Brazil, including in this approach a temporal trend analysis. A similar analysis was also conducted for precipitation. Thus, the historical data (1980-2010) from 33 weather stations were analyzed. The spatial distribution of the data was carried out by geostatistical techniques (ordinary kriging) and the trend analysis by the tests Mann-Kendall and Sen. According to the results, evapotranspiration increases from the coast to the interior of the state, with the highest values in the northeast and northwest regions, reaching levels of about 1200 mm yr-1. The temporal variability of the ET presented a significant upward trend in 12% of the locations, with increases from 2.5 to 7.0 mm yr-1. Precipitation was higher in the coastal and south-central regions and the lowest amounts were identified in the northeast and northwest regions. The precipitation trend analysis indicated a significant downward trend in precipitation volume of five locations. The evapotranspiration and precipitation showed, in general, no statistically significant trends in most of the stations analyzed; however, the upward trends for ET and downward trends for precipitation indicate local changes in the State of Paraná.
DOI: 10.6084/m9.figshare.7512170.v1
title: Space-time variability of evapotranspiration and precipitation in the State of Paraná, Brazil

description: Abstract Long-term changes in important weather variables such as evapotranspiration (ET) and precipitation are expected as a response to climate change. These changes may require adjustments to current strategies of planning and management of water resources. The objective of this work was to conduct a spatiotemporal characterization of evapotranspiration in the State of Paraná, Brazil, including in this approach a temporal trend analysis. A similar analysis was also conducted for precipitation. Thus, the historical data (1980-2010) from 33 weather stations were analyzed. The spatial distribution of the data was carried out by geostatistical techniques (ordinary kriging) and the trend analysis by the tests Mann-Kendall and Sen. According to the results, evapotranspiration increases from the coast to the interior of the state, with the highest values in the northeast and northwest regions, reaching levels of about 1200 mm yr-1. The temporal variability of the ET presented a significant upward trend in 12% of the locations, with increases from 2.5 to 7.0 mm yr-1. Precipitation was higher in the coastal and south-central regions and the lowest amounts were identified in the northeast and northwest regions. The precipitation trend analysis indicated a significant downward trend in precipitation volume of five locations. The evapotranspiration and precipitation showed, in general, no statistically significant trends in most of the stations analyzed; however, the upward trends for ET and downward trends for precipitation indicate local changes in the State of Paraná.