RESUMEN
Urban stream monitoring programs rarely consider the daily cycle of water quality. Furthermore, water quality indexes (WQIs) often rely on an excessive number of correlated parameters. To the best of our knowledge, no previous study used both the principal component analysis (PCA) and the daily cycle of the water quality of urban streams to create better WQIs. In this context, the present study aimed to develop a novel urban WQI (WQIurban) considering these two factors. Moreover, the main WQI in Brazil for water quality assessment for public supply (WQIcetesb) was used as a starting point (parameters: total solids (TS), temperature, turbidity, biochemical oxygen demand, pH, dissolved oxygen (DO), total nitrogen, total phosphorus, and thermotolerant coliforms (Escherichia coli)). The selected parameters to integrate the WQIurban received weights according to their importance for the conformation of water quality and a quality value was assigned to each parameter as a function of its concentration or measure. The developed WQIurban (parameters: pH, TS, E. coli, and DO) was able to maintain the seasonal and daily patterns of the urban stream water quality compared to the WQIcetesb. Nevertheless, the spatial relationship among the sampling sites was somewhat lacking. Our findings can help environmental managers, policy planners, and local researchers to improve their urban stream monitoring programs, saving money, time, and resources. Moreover, the WQIurban can be helpful during exceptional circumstances in which the water quality of urban streams must be quickly assessed.
Asunto(s)
Contaminantes Químicos del Agua , Calidad del Agua , Monitoreo del Ambiente , Recursos Hídricos , Escherichia coli , Ríos/química , Oxígeno/análisis , Contaminantes Químicos del Agua/análisisRESUMEN
Pollen allergies have a remarkable clinical impact all over world. Quercus pollen is the main allergen in many parts of world. Due to the health impacts caused by exposure to oak pollen, the objectives of this study are to characterise the aerobiological behaviour of Quercus pollen and to determine its potential sources as well as their transport through the atmosphere of Mexico City and surrounding areas between January 2012 and June 2015. Airborne Quercus pollen monitoring was carried out simultaneously in five zones of Mexico City. The percentage of Quercus pollen of the total pollen collected from the air showed that the highest concentration was recorded in 2014, followed by 2012. The annual seasonal variation indicated that flowering and pollen emission into the atmosphere began between February and March. The maximum concentration of Quercus pollen was reached at Cuajimalpa. In 2012, the amount of pollen grains was distributed in March and April uniformly, whilst in 2014, the largest amount of pollen was concentrated in March. In 2012 and 2014 (years with the highest pollen concentrations), corresponding intraday variations were quite similar, with a low relative maximum in the morning and the highest concentrations in the evening. The largest values were recorded in 2014, and two processes can explain these. In the afternoon, pollen from secondary forest is carried by southwesterly converging winds, increasing the pollen concentration in Cuajimalpa. In the evening, there is an additional pollen contribution from primary forest via transport by NW winds.
Asunto(s)
Monitoreo del Ambiente , Polen , Quercus , Alérgenos , Atmósfera , Ciudades , México , Estaciones del AñoRESUMEN
As part of the investigations of the experiment TRMM/LBA in Amazônia, measurements of the rain were obtained in a pasture site. In this work precipitation distribution were analyzed during the period from January 10 to February 28, 1999 (wet season). The monthly totals of precipitation for the period were 322.3 and 468.6 mm for January and February, respectively. The analyses of the frequency distribution for the events lower than 1 mm.h-1 and higher than 1, 3, 5, 10, 15 and 20 mm.h-1 showed different time distribution. The events lower than 1 mm.h-1 presented a more regular temporary distribution, even representing only 3% of the total volume of precipitation (27 mm). The events with precipitation above 1, 3, 5 mm.h-1 presented a similar pattern among them, and the most frequent cases ocurred during late afternoon. Those events represented about 97, 91 and 86% of the total of the precipitation, respectively. Finally, the events above 10, 15 and 20 mm.h-1 represented 73, 68 and 62% of the total of the precipitation respectively, and the largest relative frequencies concentrated among 2 up to 4 HL and 15 up to 17 HL. The rainfall observed can be classified in 2 distint system: local convection and mesoscale convective system, which provoke peaks at 16 LT and 4 LT, respectively.
Como parte das investigações do experimento TRMM/LBA na Amazônia, medidas de chuva foram obtidas continuamente sobre uma área de pastagem. Neste trabalho foram analisados dados de precipitação durante o período compreendido entre 10 de janeiro a 28 de fevereiro de 1999 (período chuvoso). Os totais mensais de precipitação para o período estudado foram de 322,3 e 468,6 mm para janeiro e fevereiro, respectivamente. As análises da distribuição de frequência para os eventos inferiores a 1 mm/h e superiores a 1, 3 , 5, 10, 15 e 20 mm.h-1, mostraram diferentes distribuição temporal. Os eventos inferiores a 1 mm.h-1 apresentaram uma distribuição temporal mais regular, porém representando apenas cerca de 3% do volume total de precipitação (27 mm). Os eventos com precipitação superiores a 1, 3, 5 mm.h-1 apresentaram um padrão similar entre si, sendo que os casos mais frequentes ocorreram durante a madrugada e final da tarde. Esses eventos representaram cerca de 97, 91 e 86% do total da precipitação, respectivamente. Finalmente, os eventos acima de 10, 15 e 20 mm.h-1 totalizaram, respectivamente, 73, 68 e 62% do total da precipitação, e as maiores frequências relativas concentraram-se entre 2 às 4 HL e 15 às 17 HL. A precipitação observada pode ser classificada em 2 sistemas distintos de produção de chuva: convecção isolada local e sistemas convectivos de mesoescala, os quais provocaram máximos de precipitação às 16 e 4 HL, respectivamente.
RESUMEN
As part of the investigations of the experiment TRMM/LBA in Amazônia, measurements of the rain were obtained in a pasture site. In this work precipitation distribution were analyzed during the period from January 10 to February 28, 1999 (wet season). The monthly totals of precipitation for the period were 322.3 and 468.6 mm for January and February, respectively. The analyses of the frequency distribution for the events lower than 1 mm.h-1 and higher than 1, 3, 5, 10, 15 and 20 mm.h-1 showed different time distribution. The events lower than 1 mm.h-1 presented a more regular temporary distribution, even representing only 3% of the total volume of precipitation (27 mm). The events with precipitation above 1, 3, 5 mm.h-1 presented a similar pattern among them, and the most frequent cases ocurred during late afternoon. Those events represented about 97, 91 and 86% of the total of the precipitation, respectively. Finally, the events above 10, 15 and 20 mm.h-1 represented 73, 68 and 62% of the total of the precipitation respectively, and the largest relative frequencies concentrated among 2 up to 4 HL and 15 up to 17 HL. The rainfall observed can be classified in 2 distint system: local convection and mesoscale convective system, which provoke peaks at 16 LT and 4 LT, respectively.
Como parte das investigações do experimento TRMM/LBA na Amazônia, medidas de chuva foram obtidas continuamente sobre uma área de pastagem. Neste trabalho foram analisados dados de precipitação durante o período compreendido entre 10 de janeiro a 28 de fevereiro de 1999 (período chuvoso). Os totais mensais de precipitação para o período estudado foram de 322,3 e 468,6 mm para janeiro e fevereiro, respectivamente. As análises da distribuição de frequência para os eventos inferiores a 1 mm/h e superiores a 1, 3 , 5, 10, 15 e 20 mm.h-1, mostraram diferentes distribuição temporal. Os eventos inferiores a 1 mm.h-1 apresentaram uma distribuição temporal mais regular, porém representando apenas cerca de 3% do volume total de precipitação (27 mm). Os eventos com precipitação superiores a 1, 3, 5 mm.h-1 apresentaram um padrão similar entre si, sendo que os casos mais frequentes ocorreram durante a madrugada e final da tarde. Esses eventos representaram cerca de 97, 91 e 86% do total da precipitação, respectivamente. Finalmente, os eventos acima de 10, 15 e 20 mm.h-1 totalizaram, respectivamente, 73, 68 e 62% do total da precipitação, e as maiores frequências relativas concentraram-se entre 2 às 4 HL e 15 às 17 HL. A precipitação observada pode ser classificada em 2 sistemas distintos de produção de chuva: convecção isolada local e sistemas convectivos de mesoescala, os quais provocaram máximos de precipitação às 16 e 4 HL, respectivamente.