Spatiotemporal Variations and Regional Transport of Air Pollutants in Two Urban Agglomerations in Northeast China Plain

Characteristics of air pollution in Northeast China(NEC) received less research attention in the past comparing to other heavily polluted regions in China.Spatiotemporal variations of six criteria air pollutants(PM10, PM2.5, SO2, NO2, O3 and CO) in Central Liaoning Urban Agglomeration(CLUA) and Harbin-Changchun Urban Agglomeration(HCUA) in NEC Plain were analyzed in this study based on three-year hourly observations of air pollutants and meteorological variables from 2015 to 2017.The results indicated that the annual mean concentrations of air pollutants are generally higher in the middle and southern regions in NEC Plain and lower in the northern region.Megacities such as Shenyang, Harbin and Changchun experience severe air pollution, with a three-year averaged air quality index(AQI) larger than 80, far exceeding the daily AQI standard at the first-level of 50 in China.The annual mean PM and SO2 concentrations decrease most significantly in NEC urban agglomerations from 2015 to 2017, followed by CO and NO2, while O3 shows a slight increasing trend.All the six pollutants exhibit obvious seasonal and diurnal variations, and these variations are dictated by local emission and meteorological conditions.PM2.5 and O3 concentrations in NEC urban agglomerations strongly depend on wind conditions.High O3 concentrations at different cities usually occur in presence of strong winds but are independent on wind direction(WD), while high PM2.5 is usually accompanied by weak winds and poor dispersion condition, and sometimes also occur when the northerly or southerly winds are strong.Regional transport of air pollutants between NEC urban agglomerations is common.A severe haze event on November 1–4, 2017 is examined to demonstrate the role of regional transport on pollution.

Assessment of Nitrogen Pollutant Sources in Surface Waters of Taihu Lake Region

The nitrogen （N） pollution status of the 12 most important rivers in Changshu, Taihu Lake region was investigated. Water samples were collected from depths of 0.5-1.0 m with the aid of the global positioning system （GPS）. The seasonal variations in the concentrations of different N components in the rivers were measured. Using tension-free monolith lysimeters and ^15N-labeled fertilizer, field experiments were carried out in this region to determine variations of iSN abundance of NO3^- in the leachate during the rice and wheat growing seasons, respectively. Results showed that the main source of N pollution of surface waters in the Taihu Lake region was not the N fertilizer applied in the farmland but the urban domestic sewage and rural human and animal excreta directly discharged into the water bodies without treatment. Atmospheric dry and wet N deposition was another evident source of N pollutant of the surface waters. In conclusion, it would not be correct to attribute the N applied to farmlands as the source of N pollution of the surface waters in this region.

Regional partitioning of agricultural non-point source pollution in China using a projection pursuit cluster model

A projection pursuit cluster（PPC） model was used to analyze the regional partitioning of agricultural non-point source pollution in China.The environmental factors impacting the agricultural non-point source pollution were compiled into a projection index to set up the projection index function.A novel optimization algorithm called Free search（FS） was introduced to optimize the projection direction of the PPC model.By making the appropriate improvements as we explored the use of the algorithm,it became simpler,and developed better exploration abilities.Thus,the multi-factor problem was converted into a single-factor cluster,according to the projection,which successfully avoided subjective disturbance and produced objective results.The cluster results of the PPC model mirror the actual regional partitioning of the agricultural non-point source pollution in China,indicating that the PPC model is a powerful tool in multi-factor cluster analysis,and could be a new method for the regional partitioning of agricultural non-point source pollution.

Effect of crude oil pollution on organic carbon and humus content in grey-brown soils in Mangyshlak, Pre-Caspian Sea Region

The organic carbon and humus content in oil polluted brown and grey-brown soils in Mangyshlak,Pre-Caspian Sea Region,was analyzed from 2000 to 2008.The results indicated that bitumen substances from crude oil pollution deteriorated the soil property,however,the organic carbon content increased significantly.The products of oil pollution changed the composition of car-bonaceous substances which formed soil humus,and changed the ratios of the humus components.Residual insoluble carbon increased with the rise of oil organic carbon.The mobility of humus components was significantly increased because of the high oxidation-reduction process in the topsoil,and the humus content and microorganism activity increased.The organic carbon content increased significantly,while it decreased with the distance away from the oil well.The rearrangement of physical,physical-chemical and chemical properties of the polluted soils was significant.

A Case Study of Typical Regional Pollution Transport in Fuzhou City

Based on data of PM2.5 hourly concentration and HYSPLIT model backward trajectory in coastal cities of Fujian Province during January 25 -26, 2014, a typical regional pollution process affecting Fujian from the north to the south and the east to the west on January 26 was investiga- ted. Taking Fuzhou as an example, based on weather situation on the ground and at high altitudes as well as corresponding meteorological data such as wind direction, wind velocity, and visibility, the changes of meteorological elements before, during and after the pollution were compared. Based on the V-3θ atmospheric vertical structure diagrams, the weather reasons for the generation, maintaining and dissipation of the pollution were discussed. The results indicated that the regional pollution was transported from the northeast to the southwest. The northeasterly air flow in front of the cold ridge strengthened and moved toward the east, so that the pollutant from the north affected Fujian form the north to the south and from the east to the west. As a result, there was a dramatic increase of pollutant concentration, rapid drop of visibility, and deterioration of air quality in the affected areas. The heavy pollution process featured high-speed transport and short-time generation. The air quality changed from good state to heavy pollution in just 3 -4 hours. The maximum of IAQIpM2.5 reached 280. The whole pollution process lasted for 14 hours. Solar radiation had been deeply affected by aerosol clouds, so that atmospheric stratification was extremely stable. Along with the eastward movement of cold high pressure into the sea, the dominant wind direction near the ground changed from the northeast to the east, so that the source of the pollutant was cut off , and air quality quickly turned well. The changes of atmospheric vertical structure indicated that the high inversion layer and clouds near 700 hPa kept lower air clean and blocked upper pollution transport. The later sudden increase of wind speed and strengthening of atmospheric mechanical turbu- lent destroyed inversion layer, so that the upper pollutants invaded air near the ground rapidly. During the period of high pollution, the isothermal layer （aerosol clouds） leaded to decrease of wind speed, and the atmosphere became more stable. The pollution ended until the wind field changed.

Analysis of Summertime Typical Pollution in Pearl River Delta Region——Numerical Simulation of Meteorological Field

Based on meteorological field and air quality observation data, air pollution process over Pearl River Delta （PRD） in August of 2012 was analyzed. There were five notable pollution processes in this month, in which four pollution processes were related to typhoon. By using meso-scale meteorological model WRF, meteorological characteristics of two pollution processes induced by tropical cyclone were contrasted and analyzed. Results showed that O9 and PMTo concentrations significantly increased in PRD region during Typhoon Haikui period （7 -8 August）, and other pollutant concentrations were also high. However, 03 and PM10 concentrations did not significantly increase during Typhoon Kai-Tak period （16 -17 August）. This kind of concentration difference between two processes was related to typhoon pathway, wind direction and velocity, atmospheric boundary layer height, vertical transport and horizontal divergence field.

Research on soil multi-media environmental pollution around a Pb-Zn mining and smelting plant in the karst area of Guangxi Zhuang Autonomous Region,Southwest China

The method of principal component analysis was applied to systematical research on the soil multi-media environment, including soil, surface water, ground water, waterbody sediment and agricultural crops, as well as pollution-inducing wastewater, mullock (or waste ore) and slag in the periphery of a large-sized Pb-Zn mining and smelting plant in a karst area of Guangxi Zhuang Autonomous Region. The results revealed that soils in the area studied have been heavily polluted by Cd, Zn, Pb and Hg, and the levels of these metals in the samples of agricultural crop greatly exceed the standards. The above-mentioned pollutants exist in all soil-multi-media environments. The mullock, slag, wastewater, surface water, ground water, soil, and agricultural crops constitute a composite ecological chain. Therefore, the improper disposal of mullock and slag, and the use of polluted wastewater for agricultural irrigation are the main causes of soil pollution. Heavy metals in the soil have three transition progresses: point (improved soil with slag, ground water inflow plot), linear (river transition) and non-point transition (regional pollution by slag) patterns, and the tailing yard is the most important locus for heavy metals to release into the environment.

Construction and Implementation Approaches of Ecological Compensation Mechanism for Coordinated Control of Air Pollution in Beijing-Tianjin-Hebei Region

The spatial spillover of air pollution in Beijing-Tianjin-Hebei region makes the territorial governance model inefficient.At the same time,it is facing the contradiction between environmental governance and economic development.So far,there is still no regional long-term mechanism for coordinated governance of air pollution.Ecological compensation theory is becoming an effective guiding theory to coordinate economic and environmental benefits.There is relatively little research on ecological compensation mechanism in the coordinated control of regional air pollution.Ecological compensation mechanism is an effective tool to promote air pollution control.At the same time,regional cooperation can realize the efficient control of air pollution.Scientifically constructing the cross regional cooperative control model of Beijing,Tianjin and Hebei is a favorable way to implement comprehensive control of air pollution.This paper discusses the necessity of ecological compensation mechanism for regional coordinated control of air pollution.Referring to practical experience of provinces and cities that have implemented the ecological compensation mechanism for air pollution control,and the effective way to distribute the compensation amount,compensation subject and compensation standard determination method that can be implemented in Beijing-Tianjin-Hebei region are analyzed,further proposing an effective way to establish an ecological compensation mechanism for regional air pollution collaborative control according to its reality.

Assessing the impact of manufacturing agglomeration on environmental pollution in Beijing-Tianjin-Hebei region using spatial panel data model

The Beijing-Tianjin-Hebei region is the vanguard of economic development in northern China.Its manufacturing industry is more and more developed,but environmental pollution is also more serious.Based on the data of 13 cities in Beijing-Tianjin-Hebei region from 2017 to 2021,the paper verifies the impact of manufacturing agglomeration on environmental pollution.Both manufacturing agglomeration and environmental pollution are dependent on spatial distribution.Therefore,the paper selects spatial econometric model to study.First,the spatial lag model and spatial error model are constructed,and then the spatial lag model is selected through the results of OLS regression,LM Test and Hausman test,and the empirical process is carried out.Finally,the empirical results are analyzed and the conclusion is drawn.

Regional Distribution and Pollution of Energy-lntensive Industries in China

This paper investigates the regional distribution and pollution of energyintensive industries in China. Through the analysis of provincial panel data collected during 1998-2008, this work estimates the drivers of pollution in 30 of China＇s provincial-level divisions. The paper concludes that while China＇s energy-intensive industries are heavily distributed in eastern and central China, the speed of development toward central and western China has, in recent years, risen continuously. Industries located in eastern China do, however, remain the primary polluters in the country. Notably, regional agglomeration of energy-intensive industries plays a positive role in energy conservation and pollution control in China. This paper also finds that patterns of pollution in China follow the environmental Kuznets curve （EKC） with strong inter-provincial discrepancies.

Investigating the Transport Mechanism of PM2.5 Pollution during January 2014 in Wuhan, Central China

Severe haze pollution that occurred in January 2014 in Wuhan was investigated. The factors leading to Wuhan’s PM2.5 pollution and the characteristics and formation mechanism were found to be significantly different from other megacities, like Beijing. Both the growth rates and decline rates of PM2.5 concentrations in Wuhan were lower than those in Beijing, but the monthly PM2.5 value was approximately twice that in Beijing. Furthermore, the sharp increases of PM2.5 concentrations were often accompanied by strong winds. A high-precision modeling system with an online source-tagged method was established to explore the formation mechanism of five haze episodes. The long-range transport of the polluted air masses from the North China Plain (NCP) was the main factor leading to the sharp increases of PM2.5 concentrations in Wuhan, which contributed 53.4% of the monthly PM2.5 concentrations and 38.5% of polluted days. Furthermore, the change in meteorological conditions such as weakened winds and stable weather conditions led to the accumulation of air pollutants in Wuhan after the long-range transport. The contribution from Wuhan and surrounding cities to the PM2.5 concentrations was determined to be 67.4% during this period. Under the complex regional transport of pollutants from surrounding cities, the NCP, East China, and South China, the five episodes resulted in 30 haze days in Wuhan. The findings reveal important roles played by transregional and intercity transport in haze formation in Wuhan.

Residual Levels and New Inputs of Chlorinated POPs in Agricultural Soils from Taihu Lake Region

Selected persistent organochlorine pesticides (OCPs), including 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) and its principal metabolites 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE) and 1,1-dichloro-2,2-bis(p-chlorophenyl)e- thane (DDD), hexachlorocyclohexane (HCH) and its isomers (α-,β-, γ-, and δ-HCH), hexachlorobenzene (HCB), endo- sulfan, dieldrin, and endrin were quantified to determine current levels of organochlorine pesticides, to assess the eco- toxicological potential, and to distin…

Pollution pattern of underground river in karst area of the Southwest China

Investigation of groundwater pollution has been carried out on multiple typical karst underground river systems in recent years in order to reveal the characteristics and mechanism of underground river pollution. Through the summary of the survey results, five characteristics of underground river pollution have been revealed, including directionality, weak hysteresis, easier for reversibility, linear and intermittent(or seasonal); combining with karst geomorphic types, pollution sources(primordial, secondary pollution and compound), pollution ways and pollution receptors, three basic pollution patterns of the underground river were depicted: Recharge area pollution, runoff area pollution and discharge area pollution. At the same time, the study discloses the reality of the underground river pollution is the three basic patterns and their subgenera in combination with super imposition on the space and time. And from the angle of the hydrogeological model, the study expounds the process of underground river pollution. Finally, the study gives naming rules of pollution pattern of the underground river and sets up PISAB method of pattern recognition. The results provide scientific basis for pollution repair and management of underground river in the southwest karst region.

The Environmental Impacts of Informal Economies in China: Inverted U-shaped Relationship and Regional Variances

This paper aims to the debate on the nexus between informal economies and the environment by investigating the long-term dynamic impacts of China’s informal economies on pollution and considering regional differences in informal economies’ pollution.This paper uses the Multiple Indicators Multiple Causes(MIMIC) model to estimate the size of informal economies and employs econometric models to examine their relationships to pollution based on provincial-level panel data from 2000 to 2017. The results indicate that informal economies’ effects on environmental pollution are not purely positive or negative. Rather, our model indicates that there is an inverted U-shaped relationship between informal economies and pollution in the long run in China;this means that the level of environmental pollution increases at first and then decreases with the growth of informal economies. Further analysis shows that while this inverted, U-shaped relationship is significant in different regions of China, it is affected by different environmental impact factors. The paper concludes by discussing the policy implications for environmental protection and sustainable development.

Combining CLUE-S and SWAT Models to Forecast Land Use Change and Non-point Source Pollution Impact at a Watershed Scale in Liaoning Province, China

Non-point source(NPS) pollution has become a major source of water pollution. A combination of models would provide the necessary direction and approaches designed to control NPS pollution through land use planning. In this study, NPS pollution load was simulated in urban planning, historic trends and ecological protection land use scenarios based on the Conversion of Land Use and its Effect at Small regional extent(CLUE-S) and Soil and Water Assessment Tool(SWAT) models applied to Hunhe-Taizi River Watershed, Liaoning Province, China. Total nitrogen(TN) and total phosphorus(TP) were chosen as NPS pollution indices. The results of models validation showed that CLUE-S and SWAT models were suitable in the study area. NPS pollution mainly came from dry farmland, paddy, rural and urban areas. The spatial distribution of TN and TP exhibited the same trend in 57 sub-catchments. The TN and TP had the highest NPS pollution load in the western and central plains, which concentrated the urban area and farm land. The NPS pollution load would increase in the urban planning and historic trends scenarios, and would be even higher in the urban planning scenario. However, the NPS pollution load decreased in the ecological protection scenario. The differences observed in the three scenarios indicated that land use had a degree of impact on NPS pollution, which showed that scientific and ecologically sound construction could effectively reduce the NPS pollution load in a watershed. This study provides a scientific method for conducting NPS pollution research at the watershed scale, a scientific basis for non-point source pollution control, and a reference for related policy making.

The non-point output of different agriculture landuse types in Zhexi hydraulic region of Taihu Basin

This paper takes Zhexi hydraulic region in Taihu Basin as a study area. On the basis of hydraulic analysis function of Arcgis8.3, the drainages were delineated by selecting the monitoring points and discharge stations as outlets. The landuse map were finished by denoting the TM/ETM image. The precipitation map was finished by spatial interpolation according to the rainfall monitoring records. Overlaying the drainage boundary, landuse map and precipitation map, the rainfall, different landuse type area, and runoff pollution concentration and runoff were calculated. Based on these data in different sub-watersheds, by Origin7.0 regression tool, an equation is established to predict runoff using the relationships between runoff, precipitation depth and land use patterns in each of the sub-watersheds. Selecting the sub-watershed which is mainly composed of forest landuse type, the mean runoff concentration (MRC) from sub-watershed has been estimated. The mean runoff concentration of farmland has been estimated by the same methods after the contribution of forest landuse type was removed. The results are: for the forest landuse type, the mean runoff concentrations of COD, BOD, Total N and Total P are 2.95 mg/l, 1.080 mg/l, 0.715 mg/l, and 0.039 mg/l, respectively; for the farmland, the mean runoff concentrations of COD, BOD, Total N and Total P are 5.721 mg/l, 3.097 mg/l, 2.092 mg/l, and 0.166 mg/l, respectively. By using these results, the agriculture non-point pollution loads have been assessed. The loads of COD, BOD, Total N and Total P in Zhexi region are 14,631.69 t/a, 6401.93 t/a, 4281.753 t/a and 287.67 t/a, respectively.

Assessment of heavy metals in sediment cores from Xiangjiang River,Chang-Zhu-Tan region,Hunan Province,China

Samples were collected from two core sediments(C1 and C2) of Xiangjiang River,Chang-Zhu-Tan region,Hunan Province,China.The heavy metal contents are relatively higher,especially for the surface or near the surface layers.The calculated anthropogenic factor values indicate that all the heavy metals except for Cr in the core samples are enriched,especially for Cd,with the maximum enriching coefficients of 119.44,and 84.67 in C1 and C2,respectively.The correlation of heavy metals with sulphur indicates that they are precipitated as metal sulphides.Correlation matrix shows significant association between heavy metals and mud.Factor analysis identifies that signified anthropogenic activities affect the region of Xiangjiang River.

Illustrating the multi-stakeholder perceptions of environmental pollution based on big data:Lessons from China

The relationship between stakeholders and the environment influences sustainable development and human wellbeing.To illustrate the multi-stakeholder perceptions of environmental pollution in China,we interpreted a feedback loop in the perception-behavior-environment nexus from the perspective of the coupled human-environment system,measured the differences of environmental perceptions among five stakeholders(the public,government,media,companies,and scientists)and regions(including 31 provinces,autonomous regions,and municipalities in China,with exceptions of Taiwan of China,Hong Kong of China,and Macao of China due to a lack of data)using big data,and made a comparison between the perceptions and the actual pollution situation.The results showed that the five stakeholders exhibited similar perceptions of environmental pollution at the national scale,with air pollution being of most concern,followed by water pollution and soil pollution.There were significant spatial differences in environmental perceptions.All stakeholders in the developed regions in eastern China paid relatively high attention to environmental issues,while those in the northwestern regions paid much less attention.There existed a mutual influence and interaction among the different stakeholders.More attention should be paid to air pollution in Xinjiang Uygur Autonomous Region and Ningxia Hui Autonomous Region,water pollution in Hainan Province,Inner Mongolia Autonomous Region,Heilongjiang Province,and Jilin Province,and soil pollution in Hainan Province,Fujian Province,and Jilin Province.This paper provides a research paradigm on multi-stakeholder environmental perceptions based on big data,and the results provide a background reference for regional environmental governance.