Pub Date : 2021-01-01DOI: 10.1590/2318-0331.262120210067
Carla Fernanda Perius, R. Tassi, Lucas Alves Lamberti, A. Silva, Liriane Élen Böck
ABSTRACT Using rainwater harvesting (RWH) system is influenced by socioeconomic, environmental and technical factors. This work presents as analysis of the influence of the rainfall time series characteristics and design criteria on RWH performance of five Brazilian capitals with different climatic characteristic: Goiânia, João Pessoa, Manaus, Porto Alegre and São Paulo. The analysis combined different rooftop areas, storage volumes and the indoor and outdoor demands. Rainfall temporal discretization and the types of demands were the most important characteristics when assessing RWH reliability. Daily rainfall data were suitable for sizing the RWH, the time series length influenced the sizing of larger storage volumes, and the RWH efficiency was not significantly affected by the first-flush. Toilet flushing and the irrigation demands had the greatest impact on RWH performance. The greatest potentials for the implementation of RWH were observed for Porto Alegre, because of well distributed rainfall throughout the year, and for Manaus owing to higher annual volumes of precipitation. These results highlight relevant aspects that must be observed during the conception and design of RWH, complementing the guidelines provided in the Brazilian technical standards.
{"title":"Influence of rainfall and design criteria on performance of rainwater harvesting systems placed in different Brazilian climatological conditions","authors":"Carla Fernanda Perius, R. Tassi, Lucas Alves Lamberti, A. Silva, Liriane Élen Böck","doi":"10.1590/2318-0331.262120210067","DOIUrl":"https://doi.org/10.1590/2318-0331.262120210067","url":null,"abstract":"ABSTRACT Using rainwater harvesting (RWH) system is influenced by socioeconomic, environmental and technical factors. This work presents as analysis of the influence of the rainfall time series characteristics and design criteria on RWH performance of five Brazilian capitals with different climatic characteristic: Goiânia, João Pessoa, Manaus, Porto Alegre and São Paulo. The analysis combined different rooftop areas, storage volumes and the indoor and outdoor demands. Rainfall temporal discretization and the types of demands were the most important characteristics when assessing RWH reliability. Daily rainfall data were suitable for sizing the RWH, the time series length influenced the sizing of larger storage volumes, and the RWH efficiency was not significantly affected by the first-flush. Toilet flushing and the irrigation demands had the greatest impact on RWH performance. The greatest potentials for the implementation of RWH were observed for Porto Alegre, because of well distributed rainfall throughout the year, and for Manaus owing to higher annual volumes of precipitation. These results highlight relevant aspects that must be observed during the conception and design of RWH, complementing the guidelines provided in the Brazilian technical standards.","PeriodicalId":54151,"journal":{"name":"RBRH-Revista Brasileira de Recursos Hidricos","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83404213","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.1590/2318-0331.262120210098
C. K. Novakoski, Rute Ferla, P. S. Priebe, Aline Saupe Abreu, M. Marques, Maurício Dai Prá, A. V. Canellas, E. D. Teixeira
ABSTRACT Stepped spillways can dissipate a great amount of energy during the flow passage over the chute, however these structures have limited operation due to the risk of cavitation damage. The induced aeration may protect the concrete chute through the air concentration near the channel bottom. Furthermore, some research studies have indicated that the presence of air in flows may reduce the mean pressures. The present research aims to analyze mean pressures, air entrainment coefficient and flow behavior over a stepped spillway with aeration induced by two different deflectors, comparing the results to natural aeration flow. Despite the jet impact influence, the induced aeration does not change significantly the mean pressures compared to natural aeration flow. The air entrainment coefficient, as well as the jet impact position, is higher for the deflector with the longer extension and, although air bubbles can be seen throughout the extension of the chute due to the air entrainment through the inferior flow surface, the induced aeration did not anticipate the boundary layer inception point position.
{"title":"Induced aeration flow over stepped spillways: mean pressures, air entrainment and flow behavior","authors":"C. K. Novakoski, Rute Ferla, P. S. Priebe, Aline Saupe Abreu, M. Marques, Maurício Dai Prá, A. V. Canellas, E. D. Teixeira","doi":"10.1590/2318-0331.262120210098","DOIUrl":"https://doi.org/10.1590/2318-0331.262120210098","url":null,"abstract":"ABSTRACT Stepped spillways can dissipate a great amount of energy during the flow passage over the chute, however these structures have limited operation due to the risk of cavitation damage. The induced aeration may protect the concrete chute through the air concentration near the channel bottom. Furthermore, some research studies have indicated that the presence of air in flows may reduce the mean pressures. The present research aims to analyze mean pressures, air entrainment coefficient and flow behavior over a stepped spillway with aeration induced by two different deflectors, comparing the results to natural aeration flow. Despite the jet impact influence, the induced aeration does not change significantly the mean pressures compared to natural aeration flow. The air entrainment coefficient, as well as the jet impact position, is higher for the deflector with the longer extension and, although air bubbles can be seen throughout the extension of the chute due to the air entrainment through the inferior flow surface, the induced aeration did not anticipate the boundary layer inception point position.","PeriodicalId":54151,"journal":{"name":"RBRH-Revista Brasileira de Recursos Hidricos","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81828859","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.1590/2318-0331.262120210087
M. R. Stradioto, E. H. Teramoto, H. K. Chang
ABSTRACT Knowledge of mechanism controlling the hydrochemistry of groundwater are crucial requirement to understand the hydrochemical evolution and evaluate the water quality of subsurficial water resources. Thus, to understand the process governing the hydrochemistry variability and flow dynamics of the Parecis and Ronuro Aquifers, the use of statistical analysis and isotopic characterization were combined. In the correlation matrix it was found that the highest correlation coefficient was observed for HCO3-, Ca2+, Mg2+, Sr2+, SO42-, and F-, which suggested that these parameters are derived from the same source, most likely from rock–water interactions. Additionally, we noticed moderate to high correlation among NO3-, Cl-, Na+, K+, and Ba2+, which collectively are indicative of domestic sewage contamination. Finally, a principal component analysis (PCA) identified that the most variance in hydrochemistry from the evaluated samples was controlled by HCO3-, Ca2+ and Mg2+, which is associated with rock–water interaction. Regarding the 18O and 2H isotope values, it could be observed that the aquifer recharges were of meteoric origin and that the Ronuro Aquifer samples were more enriched than the PAS samples. This work reinforces the capability of multivariate statistics to discern the main process that controls the variability of groundwater hydrochemistry.
{"title":"Statistical analysis of hydrochemistry and isotopic characterization of groundwater from the Parecis Basin","authors":"M. R. Stradioto, E. H. Teramoto, H. K. Chang","doi":"10.1590/2318-0331.262120210087","DOIUrl":"https://doi.org/10.1590/2318-0331.262120210087","url":null,"abstract":"ABSTRACT Knowledge of mechanism controlling the hydrochemistry of groundwater are crucial requirement to understand the hydrochemical evolution and evaluate the water quality of subsurficial water resources. Thus, to understand the process governing the hydrochemistry variability and flow dynamics of the Parecis and Ronuro Aquifers, the use of statistical analysis and isotopic characterization were combined. In the correlation matrix it was found that the highest correlation coefficient was observed for HCO3-, Ca2+, Mg2+, Sr2+, SO42-, and F-, which suggested that these parameters are derived from the same source, most likely from rock–water interactions. Additionally, we noticed moderate to high correlation among NO3-, Cl-, Na+, K+, and Ba2+, which collectively are indicative of domestic sewage contamination. Finally, a principal component analysis (PCA) identified that the most variance in hydrochemistry from the evaluated samples was controlled by HCO3-, Ca2+ and Mg2+, which is associated with rock–water interaction. Regarding the 18O and 2H isotope values, it could be observed that the aquifer recharges were of meteoric origin and that the Ronuro Aquifer samples were more enriched than the PAS samples. This work reinforces the capability of multivariate statistics to discern the main process that controls the variability of groundwater hydrochemistry.","PeriodicalId":54151,"journal":{"name":"RBRH-Revista Brasileira de Recursos Hidricos","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74638396","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.1590/2318-0331.262120210071
Rafael Brandão Ferreira de Moraes, F. V. Gonçalves
ABSTRACT The low density of precipitation gauges, the areas of difficult access and the high number of missing values hinder a rapid and effective hydrological monitoring. Thus, the present study aims to statistically validate the precipitation estimates by the data Tropical Rainfall Measuring Mission (TRMM) in relation to the data observed in the Conventional Meteorological Stations (CMSs) in the geographic regions of Brazil. The statistical indicators used were: Correlation Coefficient (r), Mean Absolute Error (MAE), Percentage of Bias (Pbias), T-Test and Mann-Witiney Test. It is concluded that the precipitation data estimated via TRMM are effective and reliable alternatives for hydrological studies in areas that do not have in-situ gauges and/or need to fill missing values in the five regions of the country, especially in the driest months and in larger time scales.
{"title":"Validation of TRMM data in the geographical regions of Brazil","authors":"Rafael Brandão Ferreira de Moraes, F. V. Gonçalves","doi":"10.1590/2318-0331.262120210071","DOIUrl":"https://doi.org/10.1590/2318-0331.262120210071","url":null,"abstract":"ABSTRACT The low density of precipitation gauges, the areas of difficult access and the high number of missing values hinder a rapid and effective hydrological monitoring. Thus, the present study aims to statistically validate the precipitation estimates by the data Tropical Rainfall Measuring Mission (TRMM) in relation to the data observed in the Conventional Meteorological Stations (CMSs) in the geographic regions of Brazil. The statistical indicators used were: Correlation Coefficient (r), Mean Absolute Error (MAE), Percentage of Bias (Pbias), T-Test and Mann-Witiney Test. It is concluded that the precipitation data estimated via TRMM are effective and reliable alternatives for hydrological studies in areas that do not have in-situ gauges and/or need to fill missing values in the five regions of the country, especially in the driest months and in larger time scales.","PeriodicalId":54151,"journal":{"name":"RBRH-Revista Brasileira de Recursos Hidricos","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81621608","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.1590/2318-0331.262120210072
J. M. Carvalho, T. Bleninger
ABSTRACT Water reservoirs have the function to control the temporal variability of the water availability, thus bringing greater security over these resources. The water quality of these systems must be adequate for their multiple uses, and one of the main tools to understand it, is mathematical modelling. Given the importance of the water quality, the goal of this paper is to develop an analysis that takes into account the randomness of the variables that affect the thermal and/or biochemical regimes of a reservoir. For this, it is proposed a combination of deterministic and statistical analysis, where the probabilities of occurrence of a given event are considered. Difficult factors, such as the lack of data on the water quality and other variables, were considered, which increases the replicability of the method. The research method is divided into three groups: Modelling, Scenarios and Compilation of these scenarios. Through modelling, a base layout is created, enabling the use of scenarios, which are statistically analysed, and compiled into a state-transition matrix. With this, a more robust tool to understand the dynamics of water quality in a system is obtained, since it is not heavily dependent on field measurements and is easily adaptable and replicable.
{"title":"State-transition matrices as an analysis and forecasting tool applied to water quality in reservoirs","authors":"J. M. Carvalho, T. Bleninger","doi":"10.1590/2318-0331.262120210072","DOIUrl":"https://doi.org/10.1590/2318-0331.262120210072","url":null,"abstract":"ABSTRACT Water reservoirs have the function to control the temporal variability of the water availability, thus bringing greater security over these resources. The water quality of these systems must be adequate for their multiple uses, and one of the main tools to understand it, is mathematical modelling. Given the importance of the water quality, the goal of this paper is to develop an analysis that takes into account the randomness of the variables that affect the thermal and/or biochemical regimes of a reservoir. For this, it is proposed a combination of deterministic and statistical analysis, where the probabilities of occurrence of a given event are considered. Difficult factors, such as the lack of data on the water quality and other variables, were considered, which increases the replicability of the method. The research method is divided into three groups: Modelling, Scenarios and Compilation of these scenarios. Through modelling, a base layout is created, enabling the use of scenarios, which are statistically analysed, and compiled into a state-transition matrix. With this, a more robust tool to understand the dynamics of water quality in a system is obtained, since it is not heavily dependent on field measurements and is easily adaptable and replicable.","PeriodicalId":54151,"journal":{"name":"RBRH-Revista Brasileira de Recursos Hidricos","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88261557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.1590/2318-0331.262120210057
Mayara Francisca da Silva, F. V. Gonçalves, J. Janzen
ABSTRACT Computational Fluid Dynamics (CFD) simulations of a leakage in a pressurized pipe were undertaken to determine the empirical effects of hydraulic and geometric factors on the leakage flow rate. The results showed that pressure, leakage area and leakage form, influenced the leakage flow rate significantly, while pipe thickness and mean velocity did not influence the leakage flow rate. With relation to the interactions, the effect of pressure upon leakage flow rate depends on leakage area, being stronger for great leakage areas; the effects of leakage area and pressure on leakage flow rate is more pronounced for longitudinal leakages than for circular leakages. Finally, our results suggest that the equations that predict leakage flow rate in pressurized pipes may need a revision.
{"title":"Effect of hydraulic and geometric factors upon leakage flow rate in pressurized pipes","authors":"Mayara Francisca da Silva, F. V. Gonçalves, J. Janzen","doi":"10.1590/2318-0331.262120210057","DOIUrl":"https://doi.org/10.1590/2318-0331.262120210057","url":null,"abstract":"ABSTRACT Computational Fluid Dynamics (CFD) simulations of a leakage in a pressurized pipe were undertaken to determine the empirical effects of hydraulic and geometric factors on the leakage flow rate. The results showed that pressure, leakage area and leakage form, influenced the leakage flow rate significantly, while pipe thickness and mean velocity did not influence the leakage flow rate. With relation to the interactions, the effect of pressure upon leakage flow rate depends on leakage area, being stronger for great leakage areas; the effects of leakage area and pressure on leakage flow rate is more pronounced for longitudinal leakages than for circular leakages. Finally, our results suggest that the equations that predict leakage flow rate in pressurized pipes may need a revision.","PeriodicalId":54151,"journal":{"name":"RBRH-Revista Brasileira de Recursos Hidricos","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78140698","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.1590/2318-0331.262120210045
M. D. D. Oliveira, Didier Gastmans, Marcelo Donadelli Sacchi, Rodrigo Esteves Rocha, Camila Cassante de Lima, V. Santos
ABSTRACT The saturated hydraulic conductivity (Ks) is an essential property for modeling water and contaminants movement into aquifers. However, Ks is extremely variable, even when considering nearby locations, which poses a challenge for modeling at catchment scales. Field measurements of Ks are most of the time expensive, time-consuming and labor-intensive. This study aimed to obtain, for modeling purposes, and using pedotransfer functions (PTFs), a composite value of Ks at a catchment scale, in a recharge area of the Guarani Aquifer System. Soil samples were taken across the study area, and the Ks for each sampling point were determined by several PTF methods. At the same locations, Ks field measurements were taken using a Guelph permeameter. Average values of Ks for all the sampling points calculated by PTFs were similar to the average value obtained by field measurements. The use of PTFs proved to be a faster and simpler method to efficiently determine the Ks value for the watershed and to capture the stochastic variation in terms of soil pore combination at the watershed scale.
{"title":"Determining a composite value for the saturated hydraulic conductivity in a recharge area of the Guarani Aquifer System, using pedotransfer functions","authors":"M. D. D. Oliveira, Didier Gastmans, Marcelo Donadelli Sacchi, Rodrigo Esteves Rocha, Camila Cassante de Lima, V. Santos","doi":"10.1590/2318-0331.262120210045","DOIUrl":"https://doi.org/10.1590/2318-0331.262120210045","url":null,"abstract":"ABSTRACT The saturated hydraulic conductivity (Ks) is an essential property for modeling water and contaminants movement into aquifers. However, Ks is extremely variable, even when considering nearby locations, which poses a challenge for modeling at catchment scales. Field measurements of Ks are most of the time expensive, time-consuming and labor-intensive. This study aimed to obtain, for modeling purposes, and using pedotransfer functions (PTFs), a composite value of Ks at a catchment scale, in a recharge area of the Guarani Aquifer System. Soil samples were taken across the study area, and the Ks for each sampling point were determined by several PTF methods. At the same locations, Ks field measurements were taken using a Guelph permeameter. Average values of Ks for all the sampling points calculated by PTFs were similar to the average value obtained by field measurements. The use of PTFs proved to be a faster and simpler method to efficiently determine the Ks value for the watershed and to capture the stochastic variation in terms of soil pore combination at the watershed scale.","PeriodicalId":54151,"journal":{"name":"RBRH-Revista Brasileira de Recursos Hidricos","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86460244","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.1590/2318-0331.262120210093
A. Pedroso, Michael Mannich
ABSTRACT Synthetic unit hydrographs (SUH) are useful tools for the estimation of maximum flows in basins lacking historical records of measurements. However, these methods have many uncertainties and do not always produce results consistent with reality. This study comparatively analyzed the uncertainty of the application of the Snyder, SCS, and Clark HUS methods, widely used, in relation to the observed hydrographs, in the Pequeno River and the Espingarda River basins, located in the State of Paraná, considered small from the point of view of the drainage area. The simulation was performed using the HEC-HMS 4.2.1 software considering a combination of parameters that produced the higher and lower peak flow, respectively named as conservative and bold approaches. It was verified that the SUH methods, in general, overestimated the peak flows for both basins under study. In addition, the results obtained showed that SUH are fundamentally conservative models so that a bold approach in estimating the parameters input leads to results with smaller errors in simulated peak flows. Even running the SUH with the real excess rainfall as input there is an overestimation of the peak flow. SCS SUH produced the highest peak flows and consequently the largest errors while Snyder’s SUH produced the smallest errors. The magnitude of the overestimation of the peak flow for the Pequeno River was up to 60 folds. Its geology features suggest a Dunnian runoff generation process, which explains the larger errors.
{"title":"The uncertainties of synthetic unit hydrographs applied for basins with different runoff generation processes","authors":"A. Pedroso, Michael Mannich","doi":"10.1590/2318-0331.262120210093","DOIUrl":"https://doi.org/10.1590/2318-0331.262120210093","url":null,"abstract":"ABSTRACT Synthetic unit hydrographs (SUH) are useful tools for the estimation of maximum flows in basins lacking historical records of measurements. However, these methods have many uncertainties and do not always produce results consistent with reality. This study comparatively analyzed the uncertainty of the application of the Snyder, SCS, and Clark HUS methods, widely used, in relation to the observed hydrographs, in the Pequeno River and the Espingarda River basins, located in the State of Paraná, considered small from the point of view of the drainage area. The simulation was performed using the HEC-HMS 4.2.1 software considering a combination of parameters that produced the higher and lower peak flow, respectively named as conservative and bold approaches. It was verified that the SUH methods, in general, overestimated the peak flows for both basins under study. In addition, the results obtained showed that SUH are fundamentally conservative models so that a bold approach in estimating the parameters input leads to results with smaller errors in simulated peak flows. Even running the SUH with the real excess rainfall as input there is an overestimation of the peak flow. SCS SUH produced the highest peak flows and consequently the largest errors while Snyder’s SUH produced the smallest errors. The magnitude of the overestimation of the peak flow for the Pequeno River was up to 60 folds. Its geology features suggest a Dunnian runoff generation process, which explains the larger errors.","PeriodicalId":54151,"journal":{"name":"RBRH-Revista Brasileira de Recursos Hidricos","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82444346","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.1590/2318-0331.262120210089
Nathana Karina Swarowski Arboit, R. Tassi, Tiago Liberalesso, D. E. Ceconi, Daniel Gustavo Allasia Piccili
ABSTRACT In this study a long-term field experiment evaluating evapotranspiration rates from irrigated and non-irrigated green roof modules, as well their impacts on stormwater control was accomplished. Six green roof modules (3 irrigated and 3 non-irrigated) vegetated with S. rupestre were monitored throughout 8 months in southern Brazil. Four non-vegetated modules (2 irrigated and 2 non-irrigated) were simultaneously assessed to understand the role of the vegetation in the whole process. The average evapotranspiration under water-stress (ETr) was 2.6 mm.day-1, while mean evapotranspiration under water-abundance (ETp) was 2.8 mm.day-1. Higher evapotranspiration rates were observed during summer, increasing the substrate storage capacity, although ETr amount along the seasons was very similar, mainly affected by climatic conditions. The long-term analysis showed that 47% of the total rainfall was converted into runoff, 21% was retained in the green roof modules and 32% was released through evapotranspiration, reinforcing the importance of vegetation as a mechanism for improving stormwater control benefits. The results of this research also allowed the establishment of a crop coefficient (Kc) time series, with a monthly average of 0.9 which permits the S. rupestre evapotranspiration to be preliminarily estimated by using equations developed for reference culture without the need of monitoring.
{"title":"Green roof evapotranspiration rates and stormwater control under subtropical climate: a case study in Brazil","authors":"Nathana Karina Swarowski Arboit, R. Tassi, Tiago Liberalesso, D. E. Ceconi, Daniel Gustavo Allasia Piccili","doi":"10.1590/2318-0331.262120210089","DOIUrl":"https://doi.org/10.1590/2318-0331.262120210089","url":null,"abstract":"ABSTRACT In this study a long-term field experiment evaluating evapotranspiration rates from irrigated and non-irrigated green roof modules, as well their impacts on stormwater control was accomplished. Six green roof modules (3 irrigated and 3 non-irrigated) vegetated with S. rupestre were monitored throughout 8 months in southern Brazil. Four non-vegetated modules (2 irrigated and 2 non-irrigated) were simultaneously assessed to understand the role of the vegetation in the whole process. The average evapotranspiration under water-stress (ETr) was 2.6 mm.day-1, while mean evapotranspiration under water-abundance (ETp) was 2.8 mm.day-1. Higher evapotranspiration rates were observed during summer, increasing the substrate storage capacity, although ETr amount along the seasons was very similar, mainly affected by climatic conditions. The long-term analysis showed that 47% of the total rainfall was converted into runoff, 21% was retained in the green roof modules and 32% was released through evapotranspiration, reinforcing the importance of vegetation as a mechanism for improving stormwater control benefits. The results of this research also allowed the establishment of a crop coefficient (Kc) time series, with a monthly average of 0.9 which permits the S. rupestre evapotranspiration to be preliminarily estimated by using equations developed for reference culture without the need of monitoring.","PeriodicalId":54151,"journal":{"name":"RBRH-Revista Brasileira de Recursos Hidricos","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78716662","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.1590/2318-0331.262120210097
D. Santos, Jonathan Gonçalves da Silva, V. Becker
ABSTRACT Eutrophication is a global problem and an important cause of the ecological health degradation of aquatic ecosystems. The aim was to evaluate the effect of prolonged drought period (2012 to 2019) on the trophic state of two Brazilian semi-arid reservoirs, Boqueirão de Parelhas (BOQ) and Passagem das Traíras (TRA). The work was carried out according to a drought classification system, based on the Standardized Precipitation Index (SPI), with an aggregated timescale of 36 months, defining three periods. In the Period I, higher values of Secchi and lower values of turbidity, solids, nutrients and chlorophyll-a were registered, when compared to the other periods, mainly in BOQ. The principal component analyses of both reservoirs reveled a showed a temporal trend of the sample units according to the consequences of the prolonged drought. The results indicated changes in limnological variables due to the reduction of accumulated water volume, and they demonstrated that prolonged droughts impact the intensification of eutrophication in both systems. The trophic state of the BOQ reservoir was changed from mesotrophic to eutrophic as a consequence of the drought, while in TRA the eutrophic state remained, but with more intensified symptoms, with higher concentration values of nutrients, solids and algal biomass.
富营养化是一个全球性问题，是导致水生生态系统生态健康退化的重要原因。目的是评估长期干旱期(2012年至2019年)对巴西两个半干旱水库boqueir o de Parelhas (BOQ)和Passagem das Traíras (TRA)营养状态的影响。这项工作是根据基于标准化降水指数(SPI)的干旱分类系统进行的，总时间尺度为36个月，确定了三个时期。与其他时期相比，第1阶段Secchi值较高，浊度、固形物、营养物质和叶绿素-a值较低，主要表现在BOQ上。两个水库的主成分分析揭示了长期干旱影响下样本单元的时间变化趋势。结果表明，由于累积水量的减少，湖泊变量发生了变化，并表明长期干旱影响了两个系统的富营养化加剧。干旱导致BOQ水库的营养状态由中营养化向富营养化转变，而TRA水库的富营养化状态仍然存在，但症状更加严重，营养物、固体和藻类生物量的浓度值更高。
{"title":"Increasy eutrophication symptoms during a prolonged drought event in tropical semi-arid reservoirs, Brazil","authors":"D. Santos, Jonathan Gonçalves da Silva, V. Becker","doi":"10.1590/2318-0331.262120210097","DOIUrl":"https://doi.org/10.1590/2318-0331.262120210097","url":null,"abstract":"ABSTRACT Eutrophication is a global problem and an important cause of the ecological health degradation of aquatic ecosystems. The aim was to evaluate the effect of prolonged drought period (2012 to 2019) on the trophic state of two Brazilian semi-arid reservoirs, Boqueirão de Parelhas (BOQ) and Passagem das Traíras (TRA). The work was carried out according to a drought classification system, based on the Standardized Precipitation Index (SPI), with an aggregated timescale of 36 months, defining three periods. In the Period I, higher values of Secchi and lower values of turbidity, solids, nutrients and chlorophyll-a were registered, when compared to the other periods, mainly in BOQ. The principal component analyses of both reservoirs reveled a showed a temporal trend of the sample units according to the consequences of the prolonged drought. The results indicated changes in limnological variables due to the reduction of accumulated water volume, and they demonstrated that prolonged droughts impact the intensification of eutrophication in both systems. The trophic state of the BOQ reservoir was changed from mesotrophic to eutrophic as a consequence of the drought, while in TRA the eutrophic state remained, but with more intensified symptoms, with higher concentration values of nutrients, solids and algal biomass.","PeriodicalId":54151,"journal":{"name":"RBRH-Revista Brasileira de Recursos Hidricos","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76280666","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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