Understanding the controlling factor of groundwater quality can enhance promoting sustainable development of groundwater resources. To this end, multivariate statistical analysis（MA） and hydrochemical analysis were ...Understanding the controlling factor of groundwater quality can enhance promoting sustainable development of groundwater resources. To this end, multivariate statistical analysis（MA） and hydrochemical analysis were introduced in this work. The results indicate that the canonical discriminant function with 7 parameters was established using the discriminant analysis（DA） method, which can afford 100% correct assignation according to the 3 different clusters（good water（GW）, poor water（PW）, and very poor water（VPW）） obtained from cluster analysis（CA）. According to factor analysis（FA）, 8 factors were extracted from 25 hydrochemical elements and account for 80.897% of the total data variance, suggesting that groundwater with higher concentrations of sodium, calcium, magnesium, chloride, and sulfate in southeastern study area are mainly affected by the natural process; the higher level of arsenic and chromium in groundwater extracted from northwestern part of study area are derived by industrial activities; domestic and agriculture sewage have important contribution to copper, iron, iodine, and phosphate in the northern study area. Therefore, this work can help identify the main controlling factor of groundwater quality in North China plain so as to make better and more informed decisions about how to achieve groundwater resources sustainable development.展开更多
Estimating the impacts on PM_(2.5)pollution and CO_(2)emissions by human activities in different urban regions is important for developing efficient policies.In early 2020,China implemented a lockdown policy to contai...Estimating the impacts on PM_(2.5)pollution and CO_(2)emissions by human activities in different urban regions is important for developing efficient policies.In early 2020,China implemented a lockdown policy to contain the spread of COVID-19,resulting in a significant reduction of human activities.This event presents a convenient opportunity to study the impact of human activities in the transportation and industrial sectors on air pollution.Here,we investigate the variations in air quality attributed to the COVID-19 lockdown policy in the megacities of China by combining in-situ environmental and meteorological datasets,the Suomi-NPP/VIIRS and the CO_(2)emissions from the Carbon Monitor project.Our study shows that PM_(2.5)concentrations in the spring of 2020 decreased by 41.87%in the Yangtze River Delta(YRD)and 43.30%in the Pearl River Delta(PRD),respectively,owing to the significant shutdown of traffic and manufacturing industries.However,PM_(2.5)concentrations in the Beijing-Tianjin-Hebei(BTH)region only decreased by 2.01%because the energy and steel industries were not fully paused.In addition,unfavorable weather conditions contributed to further increases in the PM_(2.5)concentration.Furthermore,CO_(2)concentrations were not significantly affected in China during the short-term emission reduction,despite a 19.52%reduction in CO_(2)emissions compared to the same period in 2019.Our results suggest that concerted efforts from different emission sectors and effective long-term emission reduction strategies are necessary to control air pollution and CO_(2)emissions.展开更多
Soils and other solid wastes from industrial areas of Nasirabad, Chattogram are usually dumped or used for land development. Information about the radioactivity level presented on these soil and wastes enables one to ...Soils and other solid wastes from industrial areas of Nasirabad, Chattogram are usually dumped or used for land development. Information about the radioactivity level presented on these soil and wastes enables one to assess any possible radiological hazard to humankind by the use of such materials. A total of 37 (31 soils and 6 solid waste) samples near from different types of industries along four kilometre range were collected. The presence and activity concentrations of naturally occurred radioactive materials (NORM) and anthropogenic radionuclides in the samples were estimated using HPGe detector of 40% relative efficiency. The activity concentration of <sup>226</sup>Ra, <sup>232</sup>Th and <sup>40</sup>K were found to be ranging from 8 ± 2 to 131 ± 18.33 with an average of 21 Bq<span style="white-space:nowrap;">·</span>kg<sup>-1</sup>, 10 ± 2.69 to 133 ± 15.96 with an average of 40 Bq<span style="white-space:nowrap;">·</span>kg<sup>-1</sup> and 81 ± 22.68 to 930 ± 260.40 with an average of 449 Bq<span style="white-space:nowrap;">·</span>kg<sup>-1</sup> respectively. Besides this, some hazard indices like, the radium equivalent activity (<em>Ra<sub>eq</sub></em>), external hazard index (<em>H<sub>ex</sub></em>), internal hazard index (<em>Hi<sub>n</sub></em>), and the activity concentration index (<em>I</em><sub>y</sub>) were calculated to assess the radiation hazard in this region. The averages of calculated hazard indices were within the normal limits, except the activity concentration index, which shows elevated values. The outcomes of this study could serve as important baseline radiological data for future epidemiological studies and environmental monitoring initiatives in the study area.展开更多
基金supported by the Major State Basic Research Development Program (No. 2010CB428800)the Geological Survey Projects Foundation of Institute of Hydrogeology and Environmental Geology (No. SK201308)
文摘Understanding the controlling factor of groundwater quality can enhance promoting sustainable development of groundwater resources. To this end, multivariate statistical analysis（MA） and hydrochemical analysis were introduced in this work. The results indicate that the canonical discriminant function with 7 parameters was established using the discriminant analysis（DA） method, which can afford 100% correct assignation according to the 3 different clusters（good water（GW）, poor water（PW）, and very poor water（VPW）） obtained from cluster analysis（CA）. According to factor analysis（FA）, 8 factors were extracted from 25 hydrochemical elements and account for 80.897% of the total data variance, suggesting that groundwater with higher concentrations of sodium, calcium, magnesium, chloride, and sulfate in southeastern study area are mainly affected by the natural process; the higher level of arsenic and chromium in groundwater extracted from northwestern part of study area are derived by industrial activities; domestic and agriculture sewage have important contribution to copper, iron, iodine, and phosphate in the northern study area. Therefore, this work can help identify the main controlling factor of groundwater quality in North China plain so as to make better and more informed decisions about how to achieve groundwater resources sustainable development.
基金supported by the National Science Foundation of China(Grant.No.41521004)the Gansu Provincial Special Fund Project for Guiding Scientific and Technological Innovation and Development(Grant No.2019ZX-06)the Fundamental Research Funds for the Central Universit-ies(lzujbky-2021-kb12)。
文摘Estimating the impacts on PM_(2.5)pollution and CO_(2)emissions by human activities in different urban regions is important for developing efficient policies.In early 2020,China implemented a lockdown policy to contain the spread of COVID-19,resulting in a significant reduction of human activities.This event presents a convenient opportunity to study the impact of human activities in the transportation and industrial sectors on air pollution.Here,we investigate the variations in air quality attributed to the COVID-19 lockdown policy in the megacities of China by combining in-situ environmental and meteorological datasets,the Suomi-NPP/VIIRS and the CO_(2)emissions from the Carbon Monitor project.Our study shows that PM_(2.5)concentrations in the spring of 2020 decreased by 41.87%in the Yangtze River Delta(YRD)and 43.30%in the Pearl River Delta(PRD),respectively,owing to the significant shutdown of traffic and manufacturing industries.However,PM_(2.5)concentrations in the Beijing-Tianjin-Hebei(BTH)region only decreased by 2.01%because the energy and steel industries were not fully paused.In addition,unfavorable weather conditions contributed to further increases in the PM_(2.5)concentration.Furthermore,CO_(2)concentrations were not significantly affected in China during the short-term emission reduction,despite a 19.52%reduction in CO_(2)emissions compared to the same period in 2019.Our results suggest that concerted efforts from different emission sectors and effective long-term emission reduction strategies are necessary to control air pollution and CO_(2)emissions.
文摘Soils and other solid wastes from industrial areas of Nasirabad, Chattogram are usually dumped or used for land development. Information about the radioactivity level presented on these soil and wastes enables one to assess any possible radiological hazard to humankind by the use of such materials. A total of 37 (31 soils and 6 solid waste) samples near from different types of industries along four kilometre range were collected. The presence and activity concentrations of naturally occurred radioactive materials (NORM) and anthropogenic radionuclides in the samples were estimated using HPGe detector of 40% relative efficiency. The activity concentration of <sup>226</sup>Ra, <sup>232</sup>Th and <sup>40</sup>K were found to be ranging from 8 ± 2 to 131 ± 18.33 with an average of 21 Bq<span style="white-space:nowrap;">·</span>kg<sup>-1</sup>, 10 ± 2.69 to 133 ± 15.96 with an average of 40 Bq<span style="white-space:nowrap;">·</span>kg<sup>-1</sup> and 81 ± 22.68 to 930 ± 260.40 with an average of 449 Bq<span style="white-space:nowrap;">·</span>kg<sup>-1</sup> respectively. Besides this, some hazard indices like, the radium equivalent activity (<em>Ra<sub>eq</sub></em>), external hazard index (<em>H<sub>ex</sub></em>), internal hazard index (<em>Hi<sub>n</sub></em>), and the activity concentration index (<em>I</em><sub>y</sub>) were calculated to assess the radiation hazard in this region. The averages of calculated hazard indices were within the normal limits, except the activity concentration index, which shows elevated values. The outcomes of this study could serve as important baseline radiological data for future epidemiological studies and environmental monitoring initiatives in the study area.
