| 1. |
- Rafee, Sameh A.Abou, et al.
(författare)
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Spatial trends of extreme precipitation events in the Paraná river basin
- 2020
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Ingår i: Journal of Applied Meteorology and Climatology. - 1558-8424. ; 59:3, s. 443-454
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Tidskriftsartikel (refereegranskat)abstract
- This work presents an analysis of the observed trends in extreme precipitation events in the Paraná River basin (PRB) from 1977 to 2016 (40 yr) based on daily records from 853 stations. The Mann–Kendall test and inverse-distance-weighted interpolation were applied to annual and seasonal precipitation and also for four extreme precipitation indices. The results show that the negative trends (significance at 95% confidence level) in annual and seasonal series are mainly located in the northern and northeastern parts of the basin. In contrast, except in the autumn season, positive trends were concentrated in the southern and southeastern regions of the basin, most notably for annual and summer precipitation. The spatial distributions of the indices of annual maximum 5-day precipitation and number of rainstorms indicate that significant positive trends are mostly located in the south-southeast part of the basin and that significant negative trends are mostly located in the north-northeast part. The index of the annual number of dry days shows that 88% of significant trends are positive and that most of these are located in the northern region of the PRB, which is a region with a high number of consecutive dry days (>90). The simple daily intensity index showed the highest number of stations (263) with mostly positive significant trends.
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| 2. |
- Abou Rafee, Sameh A., et al.
(författare)
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Land Use and Cover Changes versus climate shift : Who is the main player in river discharge? A case study in the Upper Paraná River Basin
- 2022
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Ingår i: Journal of Environmental Management. - : Elsevier BV. - 0301-4797. ; 309
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Tidskriftsartikel (refereegranskat)abstract
- Assessing the relative contribution of Land Use and Cover Changes (LUCC) and climate changes on runoff still represents a great challenge for water resources management. This issue is particularly critical for the Upper Paraná River Basin (UPRB), one of the most important basins in South America and responsible for most of the production of food, ethanol, and electricity generation in Brazil. In this paper, we used the Soil and Water Assessment Tool (SWAT) to quantitatively assess the relative contribution of both forcings. The simulation period included a time of great importance for climate studies, known as the 1970s global climate shift, and of great impact on river discharge within the UPRB. Three land use and cover scenarios were assigned to the 1961–1990 period of simulations, representing land use and cover during a pristine period (around the Year 1500), 1960, and 1985. Thirteen years of precipitation before and after the climate shift (considered to be the period 1974–1977) were analyzed and compared. Results showed a precipitation increase for the basin in general after the climate shift. The increase in rainfall reached up to 15% in many northern areas and more than 20% in the southern parts of the basin. By comparing all simulations, results indicate that both LUCC and precipitation increase due to the climate shift had a significant effect on the changes in annual discharge of the largest rivers of the UPRB. However, the results suggest that the impact of the precipitation increase on the discharge exceeded that of the LUCC. Between 1960 and 1985 the LUCC accounts for about 16% of the increase of the median annual discharge, whereas climate shift accounts for an increase of about 32%. These findings, suggesting a more relevant role for the climate, are consistent with two recent water crisis experienced by the country in the last decades, caused by prolonged below-normal rainfall throughout 2001/2002 and again in 2014/2015.
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| 3. |
- de Almeida, Daniela S., et al.
(författare)
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Genotoxic effects of daily personal exposure to particle mass and number concentrations on buccal cells
- 2018
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Ingår i: Atmospheric Environment. - : Elsevier BV. - 1352-2310. ; 176, s. 148-157
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study is to assess personal exposure to Particle Number Concentrations (PNC) in four size ranges between 0.3 and 10 μm, and particulate matter (PM1; PM2.5; PM4; PM10) in order to evaluate possible genotoxic effects through a comet assay in buccal cells. A convenience cohort of 30 individuals from a Brazilian medium-sized city was selected. These individuals aged between 20 and 61 and worked in typical job categories (i.e., administrative, commerce, education, general services and transport). They were recruited to perform personal exposure measurements during their typical daily routine activities, totaling 240 h of sampling. The 8-h average mass concentrations in air for volunteers ranged from 2.4 to 31.8 μg m−3 for PM1, 4.2–45.1 μg m−3 for PM2.5, 7.9–66.1 μg m−3 for PM4 and from 23.1 to 131.7 μg m−3 for PM10. The highest PNC variation was found for 0.3–0.5 range, between 14 and 181 particles cm−3, 1 to 14 particles cm−3 for the 0.5–1.0 range, 0.2 to 2 particles cm−3 for the 1.0–2.5 range, and 0.06 to 0.7 particles cm−3 for the 2.5–10 range. Volunteers in the ‘education’ category experienced the lowest inhaled dose of PM2.5 as opposed to those involved in ‘commercial‘ activities with the highest doses for PM10 (1.63 μg kg−1 h−1) and PM2.5 (0.61 μg kg−1 h−1). The predominant cause for these high doses was associated with the proximity of the workplace to the street and vehicle traffic. The comet assay performed in buccal cells indicated that the volunteers in ‘commerce’ category experienced the highest damage to their DeoxyriboNucleic Acid (DNA) compared with the control category (i.e. ‘education’). These results indicate the variability in personal exposure of the volunteers in different groups, and the potential damage to DNA was much higher for those spending time in close proximity to the vehicle sources (e.g. commercial services) leading to exposure to a higher fraction of fine particles. This study builds understanding on the exposure of people in different job categories, and provide policy makers with useful information to tackle this neglected issue.
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| 4. |
- Rafee, Sameh A.Abou, et al.
(författare)
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Large-scale hydrological modelling of the Upper Paraná River Basin
- 2019
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Ingår i: Water. - : MDPI AG. - 2073-4441. ; 11:5
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Tidskriftsartikel (refereegranskat)abstract
- The Upper Paraná River Basin (UPRB) has undergone many rapid land use changes in recent decades, due to accelerating population growth. Thus, the prediction of water resources has crucial importance in improving planning and sustainable management. This paper presents a large-scale hydrological modelling of the UPRB, using the Soil andWater Assessment Tool (SWAT) model. The model was calibrated and validated for 78 outlets, over a 32-year simulation period between 1984 and 2015. The results and the comparison between observed and simulated values showed that after the calibration process, most of the outlets performed to a satisfactory level or better in all objective functions analyzed with 86%, 92%, 76%, 88%, and 74% for Percent bias, Coefficient of determination, Nash-Sutcliffe efficiency, Kling-Gupta efficiency, and the Ratio of Standard deviation of observations to root mean square error, respectively. The model output provided in this work could be used in further simulations, such as the evaluation of the impacts of land use change or climate change on river flows of the Upper Paraná Basin.
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