Support vector regression(SVR) method is a novel type of learning machine algorithms,which is seldom applied to the development of urban atmospheric quality models under multiple socio-economic factors.This study pres...Support vector regression(SVR) method is a novel type of learning machine algorithms,which is seldom applied to the development of urban atmospheric quality models under multiple socio-economic factors.This study presents four SVR models by selecting linear,radial basis,spline,and polynomial functions as kernels,respectively for the prediction of urban dust fall levels.The inputs of the models are identified as industrial coal consumption,population density,traffic flow coefficient,and shopping density coefficient.The training and testing results show that the SVR model with radial basis kernel performs better than the other three both in the training and testing processes.In addition,a number of scenario analyses reveal that the most suitable parameters(insensitive loss function ε,the parameter to reduce the influence of error C,and discrete level or average distribution of parameters σ) are 0.001,0.5,and 2000,respectively.展开更多
Tightening of air quality standards for populated urban areas has led to increasing attention to assessment of air quality management areas, where violation of air quality standards occurs, and development of control ...Tightening of air quality standards for populated urban areas has led to increasing attention to assessment of air quality management areas, where violation of air quality standards occurs, and development of control strategies to eliminate such vio-lation of air quality standards. The Quetta urban area is very densely built and has heavy motorized traffic. The increase of emis-sions mainly from traffic and industry are responsible for the increase in atmospheric pollution levels during the last years. The dust examined in the current study was collected by both deposit gauge and Petri dish methods at various sites of Quetta Valley. Smoke particles were obtained by bladder method from the exhausts of various types of motor vehicles. The concentration of lead found in the smoke ranged from 1.5×10?6 to 4.5×10?6.展开更多
A study of an environmental assessment of dust fall and the associated heavy metal contents was conducted during the period from the first of March 2011 to the end of February 2012 at adjoining area of a phosphate fer...A study of an environmental assessment of dust fall and the associated heavy metal contents was conducted during the period from the first of March 2011 to the end of February 2012 at adjoining area of a phosphate fertilizer plant. Around the industrial area 8 dust fall stations were established and one of them was built upwind far from pollution activities to be taken as a control sample. Dust fall samples collected monthly weighed and then prepared to be analyzed through Inductively Coupled Plasma-Mass Spectroscopy (ICP-MS) to obtain heavy metal concentration. Meteorological parameters influencing the distribution of dust fall such as wind speed and direction, temperature, humidity, rain fall and pressure were determined. Results showed that deposition flow rates were 38.2. 47.5, 57.7, 44.3, 39.4, 38.2, 42.7 and 5.9 g/m2·month for the sites No., 1, 2, 3, 4, 5, 6, 7 and 8 respectively, and were compared with the findings of other investigators of like industrial areas worldwide. Levels of heavy metal As, Cu, Pb, Zn, Cd, and Hg in the deposited dust fall were 3.30, 26.46, 22.33, 235.00, 4.53 and 3.80 μg/g respectively. Enrichment coefficients of the heavy metals in the dust fall were found to be significant and reached the values 1.81, 0.90, 0.85, 0.65, 0.41 and 0.35 for zinc, lead, cadmium, copper, mercury and arsenic respectively. The paper ends with results and recommendations suggesting a methodology to remediate the investigated area polluted with heavy metals and control measures for the fertilizer plant to reduce pollution into the surrounding environment.展开更多
Samples of near-surface atmosphere dust-fall and different pollution end-members were collected in the urban area of Jining City. The element characteristics of the near-surface atmosphere dust-fall and pollution end-...Samples of near-surface atmosphere dust-fall and different pollution end-members were collected in the urban area of Jining City. The element characteristics of the near-surface atmosphere dust-fall and pollution end-members were analyzed systematically and the spatial distribution of the dust-fall and its pollution sources were studied. The results showed that the contents of elements varied obviously in different pollution end-members. The contents of As,Cd,Cu,F,Pb,S and Se within coal dust-fall were the highest,higher than those in atmosphere dust-fall and had great influences on the environment. The contents of Cd,Pb,Se,Zn,Hg and CaO within near-surface atmosphere dust-fall were affected by human activities to different degrees. Results of correlation analysis and factor analysis showed that Cd,Pb,Se and Zn mainly came from enterprise coal consumption,with a contribution ratio of 26. 32%. The contents of the above four elements near chemical factories,steel factories and high populated regions were generally high,which was consistent with the spatial distribution of the coal pollution sources.CaO was related to traffic pollution,with a contribution ratio of 10. 06%. Hg was mainly due to automobile emissions,with a contribution ratio of 8. 12%. The contents of As,Cr,F and Ni within dust-fall were seldom influenced by human activities and mainly came from soil sedimentation( natural sources),with a contribution ratio of 30%. The above four pollution sources( enterprise coal consumption,traffic pollution,automobile emissions and soil sedimentation) were the main sources of atmosphere dust-fall in Jining City. The enrichment coefficients of As,Cr,F and Ni were smaller and the spatial correlations of the four elements were better,while the enrichment coefficients and variable coefficients of elements influenced by human activities,such as Cd,Pb,Se and Hg were larger,and the spatial distributions of these elements were consistent with those of the pollution sources.展开更多
基金Projects(2007JT3018, 2008JT1013, 2009FJ4056) supported by the Key Project in Hunan Science and Technology Program, ChinaProject(20090161120014) supported by the New Teachers Sustentation Fund in Doctoral Program, Ministry of Education, China
文摘Support vector regression(SVR) method is a novel type of learning machine algorithms,which is seldom applied to the development of urban atmospheric quality models under multiple socio-economic factors.This study presents four SVR models by selecting linear,radial basis,spline,and polynomial functions as kernels,respectively for the prediction of urban dust fall levels.The inputs of the models are identified as industrial coal consumption,population density,traffic flow coefficient,and shopping density coefficient.The training and testing results show that the SVR model with radial basis kernel performs better than the other three both in the training and testing processes.In addition,a number of scenario analyses reveal that the most suitable parameters(insensitive loss function ε,the parameter to reduce the influence of error C,and discrete level or average distribution of parameters σ) are 0.001,0.5,and 2000,respectively.
基金Project partly supported by University of Balochistan, Pakistan
文摘Tightening of air quality standards for populated urban areas has led to increasing attention to assessment of air quality management areas, where violation of air quality standards occurs, and development of control strategies to eliminate such vio-lation of air quality standards. The Quetta urban area is very densely built and has heavy motorized traffic. The increase of emis-sions mainly from traffic and industry are responsible for the increase in atmospheric pollution levels during the last years. The dust examined in the current study was collected by both deposit gauge and Petri dish methods at various sites of Quetta Valley. Smoke particles were obtained by bladder method from the exhausts of various types of motor vehicles. The concentration of lead found in the smoke ranged from 1.5×10?6 to 4.5×10?6.
文摘A study of an environmental assessment of dust fall and the associated heavy metal contents was conducted during the period from the first of March 2011 to the end of February 2012 at adjoining area of a phosphate fertilizer plant. Around the industrial area 8 dust fall stations were established and one of them was built upwind far from pollution activities to be taken as a control sample. Dust fall samples collected monthly weighed and then prepared to be analyzed through Inductively Coupled Plasma-Mass Spectroscopy (ICP-MS) to obtain heavy metal concentration. Meteorological parameters influencing the distribution of dust fall such as wind speed and direction, temperature, humidity, rain fall and pressure were determined. Results showed that deposition flow rates were 38.2. 47.5, 57.7, 44.3, 39.4, 38.2, 42.7 and 5.9 g/m2·month for the sites No., 1, 2, 3, 4, 5, 6, 7 and 8 respectively, and were compared with the findings of other investigators of like industrial areas worldwide. Levels of heavy metal As, Cu, Pb, Zn, Cd, and Hg in the deposited dust fall were 3.30, 26.46, 22.33, 235.00, 4.53 and 3.80 μg/g respectively. Enrichment coefficients of the heavy metals in the dust fall were found to be significant and reached the values 1.81, 0.90, 0.85, 0.65, 0.41 and 0.35 for zinc, lead, cadmium, copper, mercury and arsenic respectively. The paper ends with results and recommendations suggesting a methodology to remediate the investigated area polluted with heavy metals and control measures for the fertilizer plant to reduce pollution into the surrounding environment.
基金Supported by Program of Ecological and Geochemical Survey in the Lower Reach of the Yellow River in Shandong Province(1212010310306)
文摘Samples of near-surface atmosphere dust-fall and different pollution end-members were collected in the urban area of Jining City. The element characteristics of the near-surface atmosphere dust-fall and pollution end-members were analyzed systematically and the spatial distribution of the dust-fall and its pollution sources were studied. The results showed that the contents of elements varied obviously in different pollution end-members. The contents of As,Cd,Cu,F,Pb,S and Se within coal dust-fall were the highest,higher than those in atmosphere dust-fall and had great influences on the environment. The contents of Cd,Pb,Se,Zn,Hg and CaO within near-surface atmosphere dust-fall were affected by human activities to different degrees. Results of correlation analysis and factor analysis showed that Cd,Pb,Se and Zn mainly came from enterprise coal consumption,with a contribution ratio of 26. 32%. The contents of the above four elements near chemical factories,steel factories and high populated regions were generally high,which was consistent with the spatial distribution of the coal pollution sources.CaO was related to traffic pollution,with a contribution ratio of 10. 06%. Hg was mainly due to automobile emissions,with a contribution ratio of 8. 12%. The contents of As,Cr,F and Ni within dust-fall were seldom influenced by human activities and mainly came from soil sedimentation( natural sources),with a contribution ratio of 30%. The above four pollution sources( enterprise coal consumption,traffic pollution,automobile emissions and soil sedimentation) were the main sources of atmosphere dust-fall in Jining City. The enrichment coefficients of As,Cr,F and Ni were smaller and the spatial correlations of the four elements were better,while the enrichment coefficients and variable coefficients of elements influenced by human activities,such as Cd,Pb,Se and Hg were larger,and the spatial distributions of these elements were consistent with those of the pollution sources.
