Pearl River Delta Economic Zone Research Articles

Distribution of potentially toxic elements in soils and sediments in Pearl River Delta, China: Natural versus anthropogenic source discrimination

Although anthropogenic contamination has been regarded as the most important source of potentially toxic elements (PTEs) in soils of large river delta plains, the extent to which human activities affect PTEs in soils is worth exploring. This study used high density geochemical data to distinguish source patterns of PTEs in soils of the Pearl River Delta Economic Zone, a large industrialized and urbanized area in China. Enrichment factor, discriminant analysis, principal components analysis, cumulative distribution function, and positive matrix factorization were used to identify sources of PTEs in soils. The results indicated that parent material was the most significant factor affecting geochemical characteristics of PTEs in soils. Median concentrations of Cd, Cr, Cu, Hg, Pb, and Zn were 0.400, 88.5, 40.5, 0.143, 43.0, and 116.0 mg/kg for stream sediments, 0.333, 75.7, 39.0, 0.121, 42.6, and 98.5 mg/kg for deep soils, and 0.365, 74.0, 45.1, 0.143, 44.6, and 119.5 mg/kg for surface soils, respectively, all of which exceed relevant reference standards. Compared with stream sediments and deep soils, surface soils exhibit substantial concentrations of PTEs. Chemical weathering and erosion of parent materials distributed in the Pearl River Delta were the main sources of PTEs in soils. Diffuse contamination and many small local contamination sources distributed throughout the study area were the most significant anthropogenic sources of PTEs in surface soils. Intensive human activities failed to change the soil geochemical characteristics derived from the parent material at the regional scale. However, it could induce non-point source pollution and local severe PTEs pollution in surface soils.

Provincial Inclusive Green Growth Efficiency in China: Spatial Correlation Network Investigation and Its Influence Factors

Inclusive green growth efficiency (IGGE) analysis is an effective tool for improving coordinated economic, social, and environmental development. This study incorporated the game cross-efficiency DEA to measure the IGGE of 30 provinces in China. Then, the modified spatial gravity model and social network analysis model were applied to construct and analyze the spatial correlation network structure of the IGGE. The quadratic assignment procedure was used to mine the influencing factors that affect the formation and evolution of the spatial correlation network of the IGGE. The results are as follows. (1) During the study period, there were significant differences in the IGGE among the 31 provinces, among which the eastern provinces were higher than the central and western provinces. (2) The spatial correlation of the IGGE presented a complex and multi-threaded network structure, indicating that the IGGE has a noticeable cross-regional spillover effect. Beijing, Tianjin, Zhejiang, Shanghai, Jiangsu, and Guangdong played the role of the “net spillover” block. Qinghai, Guizhou, Guangxi, and the surrounding provinces played the role of the “primary beneficial”. The Yangtze delta and Pearl River Delta economic zone (primarily including Shanghai and Guangdong) acted as a “bridge” to the Yunnan–Guizhou region and the surrounding provinces. (3) The spatial adjacency, degree of openness, economic development, and environmental governance were the prominent factors influencing the formation and evolution of the IGGE spatial correlation network. This work provides an example of constructing an IGGE correlation network while considering various factors, such as the economy, population, and distance. It also could help policymakers clarify the IGGE spatial correlation pattern and the provinces’ roles and potential for IGGE synergic improvement.

Empirical study on green development of marine economy driven by marine scientific and technological innovation and its influencing factors

In this study, the green development of marine economy driven by marine scientific and technological innovation is empirically studied and the influencing factors are analyzed. The results show that the development of marine science and technology is significantly positively correlated with the green development of marine economy as a whole, and each input variable has a promoting effect on economic development, but with varied degree of effect. The analysis on the growth models of “Circum-Bohai Sea Economic Zone,” “Yangtze River Delta Economic Zone” and “Pearl River Delta Economic Zone” shows that at present, science and technology in each marine economic zone play an obvious role in promoting economic development, and each input variable plays a different role in promoting the green development of regional marine economy. With the help of threshold panel model, the influences of five factors, namely opening to the outside world, government investment, financial development, human capital and technology investment, on the green development of marine economy driven by marine scientific and technological innovation are investigated, and it is concluded that all kinds of external influencing factors will interfere with the role of marine scientific and technological innovation and achieve the effect of promoting or restricting it.

Convergence analysis of Chinese urban green land-use efficiency

Convergence analysis of China's urban green land-use efficiency (GLUE) will help to explore whether regional differences in GLUE determined by regional economic development and imbalance of resource endowments gradually decrease over time. We construct a DEA model considering variable returns to scale to measure Chinese urban GLUE, and discuss the convergence of Chinese urban GLUE. We find that Chinese urban GLUE is generally low. GLUE of eastern cities is the best. GLUE of non-resource-based (NRB) cities is higher than that of resource-based (RB) cities. GLUE of Pearl River Delta Economic Zone is the highest, while that of Comprehensive Economic Zone of Central 6 Provinces is the lowest. Chinese urban GLUE is mainly affected by technological change. Chinese urban GLUE shows absolute and conditional β convergence, and the gap of GLUE between cities is constantly narrowing. Cities in different locations, resource dependence degrees, and economic zones have different convergence rates. The conclusions help the Chinese government to formulate policies for intensive land use, improve national GLUE, and promote urban intensive and high-quality development.

The Expansion Dynamics and Modes of Impervious Surfaces in the Guangdong-Hong Kong-Macau Bay Area, China

Different urban growth patterns have various impact degrees on the urban ecosystem and environment. Impervious surface, a typical artificial construction can be used to reflect urban development. Therefore, this study estimated the spatiotemporal dynamics and expansion patterns of impervious surface area (ISA) in the Guangdong-Hong Kong-Macau (GHM) Bay Area since the establishment of the “Pearl River Delta economic zone” in 1994. Landsat time-series images were used to map the distribution of the ISA based on the combinational biophysical composition index (CBCI) and the bidirectional temporal filtering method (BTFM). The results indicated that the ISA in the GHM Bay Area drastically expanded from 569.23 km2 in 1994 to 10,200.53 km2 in 2016. In addition, the aggregation index (AI) value of the high-density area showed a decreasing trend from 1994 to 2004. However, the value of each landscape metric rapidly increased after 2004. Moreover, the mean ratio of the major axis to the minor axis of standard deviational ellipses from 1994 to 2004 was higher than that from 2005 to 2016. The results of landscape metrics and standard deviational ellipses indicated that the ISA growth pattern changed from edge expanding and leapfrogging to infilling and consolidation, with a turning point in 2004. Moreover, the principal sprawl orientation of the ISA was northwest to southeast before 2004. After 2004, the expansion direction of the ISA was less obvious due to the development pattern of infilling and consolidation. The rapid increase of GDP and population are the driving forces of urban expansion. However, topography and ecological protection policies as the limiting factors, which caused the infilling of the inner city and redevelopment of old urban areas.

Air quality and synergistic health effects of ozone and nitrogen oxides in response to China’s integrated air quality control policies during 2015–2019

O3 pollution had been worsening in mainland China in the past decade, posing significant human health challenges. The NOx control would trigger increasing O3 concentrations in response to a series of released China emission reduction policies. This study used sensitivity analysis methodology to explore the effectiveness of integrated sectoral emission control policies that have been expanded throughout China. Air quality and synergistic health effects of O3 and NO2 were investigated to obtain an in-depth understanding of the O3 control, especially under a VOC-limited regime. The findings demonstrated that although the NOx-titration effect triggered an increase in O3, the combined health effects of two pollutants tended to improve in most regions of China under a VOC-limited regime. The region-based annual average NO2 concentrations exhibited a larger reduction in Hong Kong (HK) than in the Pearl River Delta Economic Zone (PRD EZ). The short-term measures led to substantial health benefits for Shenzhen and HK. The sectoral emission controls demonstrated a considerable health improvement for the major PRD EZ cities. Joint national control efforts confined the domain-wide health risks below the safety line in China. National cooperative efforts in China could avoid more than 1.5–2% of the emergency hospital admissions for cardiovascular and respiratory diseases attributed to NO2 and O3 exposure. The observed O3 increases due to the NOx-titration effect for calculating the integral health effects of emission control on concentration reduction called for simultaneously strengthened controls on both NOx and VOC in areas subject to a VOC-limited regime.

Assessing PM2.5 emissions in 2020: The impacts of integrated emission control policies in China

Problems with PM2.5 pollution in the Pearl River Delta (PRD) have been significantly reduced since the Chinese government released a series of emission control policies including the strengthened controls in the 13th Five-Year Plan. This study assessed the efficacy of emission control measures using the Community Multiscale Air Quality (CMAQ) model to provide data-driven support to government decision making, which is becoming increasingly important. This study aimed to quantitatively evaluate the integrated results of proposed policies for controlling PM2.5 concentrations. Accordingly, the regional 2015 emission inventory was modified with recently released government data for the PRD, and scenarios for four dynamical emission-reduction policies (S1–S4) were explored. The results show that all four proposed control measures can help to reduce PM2.5 concentrations throughout Hong Kong (HK), Macao, and the PRD economic zone (PRD EZ) by 2020. In all cases, reductions in PM2.5 concentrations were larger over PRD EZ than over HK. For HK, the predicted annual concentrations of PM2.5 were less than 20 μg/m3 for S1–S3 and less than 15 μg/m3 for S4. For Macao, the predicted annual concentrations of PM2.5 were less than 25 μg/m3 for S1 and less than 15 μg/m3 up to S3. Regionally, HK had the lowest PM2.5 levels, and the area around Foshan had the highest. Controlling the sources of air pollution (i.e., industry, transport, power production, and other sources) within PRD can get most of the PRD EZ region to below 35 μg/m3. Similar national air quality management efforts could reduce PM2.5 levels to less than 25 μg/m3 in the PRD EZ and less than 15 μg/m3 in HK. Control measures in S1 led to significant improvement in Shenzhen and HK, but the S3 option brought the greatest improvement for PRD EZ and Macao. The S4 policy option led to substantial reductions, particularly for HK.

Comparative study of municipal solid waste disposal in three Chinese representative cities

China is facing severe environmental problems, the total municipal solid waste (MSW) generation has dramatically increased and presented great challenges all over the country. Cities have different characteristics in MSW components, generation quantity, influencing factors and disposal ways. Beijing, Guangzhou and Lhasa of Beijing-Tianjin-Hebei economic circle, Pearl River Delta economic zone, and Qinghai-Tibet plateau regions were selected as representative cities, to compare and analyze the features, influencing factors to the MSW generation quantities, and its components by grey correlation analysis. Predictions of MSW generation quantities for Beijing, Guangzhou and Lhasa in 2025 would be 1251.22, 704.71 and 71.040 million tons, respectively, made by BP (back propagation) nerve work using MATLAB software. Results showed that the main indicators of influencing factors to MSW in three cities were all of economic development levels, population and investments of government input. Based on the analysis of internal relationship and characteristics of MSW, some barriers of MSW management were analyzed, and recommendations were given. Our study analyzed the influencing factors and forecasted quantities of MSW generation in representative cities in China, providing valuable evidences for the severe MSW disposal situation of different economic zones in China.

Sustainable use zoning of land resources considering ecological and geological problems in Pearl River Delta Economic Zone, China

The Pearl River Delta Economic Zone is one of the fastest growing areas of China’s social and economic development. However, the contradiction between people and land, the deterioration of ecological environment and the damage of urban ecological security have become more serious problems. In previous studies there was single land utilization type in small-area and the evaluation method was not suitable to large areas, this study proposes a new method. Firstly, the study implements ecological land zoning from assessing the importance of ecosystem services functional in four aspects: biodiversity, water conservation, soil conservation and coastal protected zone. Then, the suitability evaluation index system of agricultural and construction land is established from the geological environment perspective, and introduces variable weight-analytical hierarchy process-comprehensive index model to evaluate the suitability of agricultural land and construction land. Re-zoning the type of land that has a special effect on the socio-economic, the mining land, protected area of geological relics and groundwater resources, respectively. Finally, considering the actual condition use status and suitability distribution of land, the results of comprehensive zoning of land utilization is got. The results of this study can provide some geological basis for the future land utilization zoning.

The empowerment of rural migrantlalas: Contending queerness and heteronormativity in China

In today’s China, women’s social roles continue to be rigidly associated with gender-based responsibilities that include defending the integrity of their family, entering into heteronormative marriage, and showing reproductive capabilities. Most of those who self-identify as lalas (lesbians) struggle with such issues as self-shaming emotions, disclosing their homosexuality to family members, friends, or colleagues, and dealing with family and social pressures. Within this context, I investigate queerness in a group of young Chinese rural migrant lalas working and living in the industrial area of the Pearl River Delta economic zone in South China. I draw two conclusions. First, rural-to-urban labour migration empowers rural female lalas by providing a measure of economic independence and an escape from patriarchal and homophobic family relations. Second, the integration of traditional (offline and face-to-face) socializing locations and emerging virtual communicative spaces plays an important role in the process through which possibilities of living a queer life are carved out.

Spatial and temporal patterns of air quality in the three economic zones of China

ABSTRACTThe air pollution problem in China continues to become more severe with dramatic economic development. The focus of this study was to create a map representing the spatial–temporal pattern of the air quality in the three major economic zones in China, including the Beijing–Tianjin–Hebei Economic Zone, the Yangtze River Delta Economic Zone, and the Pearl River Delta Economic Zone in 2014. A calendar view was used to visualize the daily condition of air quality and primary pollutant in each city in 2014, and geographic references were added to each visualization according to their spatial relationships. The map provides an efficient way to investigate and understand the current status of air quality and spatial–temporal patterns of air quality.

The Effects of Socioeconomic and Environmental Factors on the Incidence of Dengue Fever in the Pearl River Delta, China, 2013

BackgroundAn outbreak of dengue fever (DF) occurred in Guangdong Province, China in 2013 with the highest number of cases observed within the preceding ten years. DF cases were clustered in the Pearl River Delta economic zone (PRD) in Guangdong Province, which accounted for 99.6% of all cases in Guangdong province in 2013. The main vector in PRD was Aedes albopictus. We investigated the socioeconomic and environmental factors at the township level and explored how the independent variables jointly affect the DF epidemic in the PRD.Methodology/Principal FindingsSix factors associated with the incidence of DF were identified in this project, representing the urbanization, poverty, accessibility and vegetation, and were considered to be core contributors to the occurrence of DF from the perspective of the social economy and the environment. Analyses were performed with Generalized Additive Models (GAM) to fit parametric and non-parametric functions to the relationships between the response and predictors. We used a spline-smooth technique and plotted the predicted against the observed co-variable value. The distribution of DF cases was over-dispersed and fit the negative binomial function better. The effects of all six socioeconomic and environmental variables were found to be significant at the 0.001 level and the model explained 45.1% of the deviance by DF incidence. There was a higher risk of DF infection among people living at the prefectural boundary or in the urban areas than among those living in other areas in the PRD. The relative risk of living at the prefectural boundary was higher than that of living in the urban areas. The associations between the DF cases and population density, GDP per capita, road density, and NDVI were nonlinear. In general, higher “road density” or lower “GDP per capita” were considered to be consistent risk factors. Moreover, higher or lower values of “population density” and “NDVI” could result in an increase in DF cases.ConclusionIn this study, we presented an effect analysis of socioeconomic and environmental factors on DF occurrence at the smallest administrative unit (township level) for the first time in China. GAM was used to effectively detect the nonlinear impact of the predictors on the outcome. The results showed that the relative importance of different risk factors may vary across the PRD. This work improves our understanding of the differences and effects of socioeconomic and environmental factors on DF and supports effectively targeted prevention and control measures.

Distributional characteristics and sources of elements in soil from typical area of Pearl River Delta economic zone, Guangdong Province, China

Dongguan City, located in the Pearl River Delta economic zone of China, is famous for its rapid developing township-enterprises in the past 30 years. A total of 759 composite soil samples, including 606 surface soil samples and 153 deep soil samples, have been collected in the city. These samples have been analyzed for 13 elements (Al, As, Cu, Cd, Co, Cr, Fe, Hg, Mn, Ni, Pb, Si, and Zn) and other parameters (pH values and organic matter) to evaluate the influence of anthropic activities on the soil environmental quality and to identify the spatial distribution of heavy metals and their possible sources. The results indicate that the average concentrations of heavy metals in soil were significantly lower than the threshold of the second grade of the Soil Environment Quality Standard in China (GB15618-1995) and the soil environmental quality in this area is comparatively good. But in comparison with local soil geochemical baseline values, As, Cd, Cu, Hg, Pb, and Zn have accumulated remarkably. Specifically, the average concentrations of As, Cd, Cu, and Hg in the small part samples of the west plain and central areas are higher than the national second-grade quality standard, indicating some level of contamination. Multivariate and geostatistical methods have been applied to differentiate the influences of natural processes and human activities on the concentration of heavy metals in surface soils in the study area. Cluster and factor analyses result in the grouping of Al, As, Cr, Cu, Fe, Ni, and Si into factor F1; Co, Mn, Pb, and Zn into F2; and Cd and Hg into F3. The spatial pattern of the three factors may be well demonstrated by geostatistical analysis. It is shown that the first factor could be considered as a natural source controlled by parent material. The second factor could be referred to as “industrial and traffic pollution sources”. The source of the third factor is mainly controlled by long-term anthropic activities, including agricultural activities, fossil fuel consumption, and atmospheric deposition.

Regional Geochemical Characteristics and Influence Factors of Soil Elements in the Pearl River Delta Economic Zone, China

Soil heavy metal pollution is one of the main environmental problems in Pearl River Delta Economic Zone of China. Based on multi-purpose regional geochemical survey, regional eco-geochemical assessment, local eco-geochemical assessment and comprehensive appraisal, the eco-geochemical survey and assessment in Pearl River Delta Economic Zone of 41,698 km2 were completed. Samples from soils were collected in accordance with the two-layer grid method. Totally 54 elements and indicators for soils were determined. Compared to deep soils, the sampled surface soils are enriched in OrgC, N, P, Cd, S，Hg, Ag, B, Au, S and poor with As, Ni, I, Co, Cr, V, MgO, Sc, Al2O3, Fe2O3 etc. The characteristics of geochemical reference value of element in soil that inherited soil parent material and regional elements combined features reflected that the elements enriched in the soil was interrelated with acid rock, sandstone and shale. The spatial distribution characteristics of element regional geochemistry were conditional by regional environmental geological conditions，and effected by human activities. The Pearl River Delta plain is a typical geochemical landscape area with regional anomaly of multiple-elements. The north, western and eastern parts of the Pearl River Delta Economic Zone are quite different in geochemical features due to regional geological background, soil parent materials, geomorphic characteristics and human activities. Environment quality evaluation results show that the grade I and grade II soil accounted for 19.9% and 57.3% of the total area. Many samples that widely distributed in the economic developed of Pearl River Delta Plain area reached the third-grade of national soil environment standard. The soil enriched in Cd, Hg, As, and the area ratio accounting for 22.8% of the total area. It is mainly controlled by the geochemical background, the Pearl River Delta formation evolution process, especially the marine transgression process lead to Cd, Cu, Zn and Pb enrichment in Pearl River Delta plain. At the same time, under the influence of higher pressure of human activities, all kinds of exogenous input material carrying heavy metal pollutants on soil environmental quality also could not to ignore.

Long-term trends of fine particulate matter and chemical composition in the Pearl River Delta Economic Zone (PRDEZ), China

Understanding the trends in PM2.5 levels is essential for formulating clean air plans. This paper analyzes PM2.5 data from various published sources for the years 2000 to 2010 in the Pearl River Delta Economic Zone (PRDEZ). The long-term variation in PM2.5 mass concentration is analyzed. Results show that PM2.5, organic carbon (OC), elemental carbon (EC), and SO 4 2− show a similar trend, increasing before 2005 and then decreasing slightly. The annual average PM2.5 concentration ranges from 49.1 μg·m−3 in 2000 to 64.3 μg·m−3 in 2010, with a peak of 84.1 μg·m−3 in 2004. None of these 11 years meets the new National Ambient Air Quality standard (NAAQS) for PM2.5 (35 μg·m−3). Overall average concentrations of OC, EC, and SO 4 2− are 13.0, 6.5, and 11.8 μg·m−3, respectively. NO 3 − and NHþ4 respectively have concentrations of 1.5 μg·m−3 and 2.9 μg·m−3 in 2000 and 6.4 μg·m−3 and 5.3 μg·m−3 in 2010, with a statistically significant average annual trend of + 0.2 μg·m−3·yr−1 and + 0.1 μg·m−3·yr−1. In certain geographic regions, OC and EC contribute most of the PM2.5, while in other regions secondary water-soluble ions are more important. In general, OC and SO 4 2− are the dominant components of PM2.5, contributing 20.6% and 18.6%, respectively. These results provide, for the first time, a better understanding of the long-term PM2.5 characteristics and trends, on a species-by-species basis, in the PRDEZ. The results indicate that PM2.5 abatement needs to prioritize secondary species.

A Study of Prediction and EarlyWarning Forecast on Geochemical Accumulation of Soil Heavy Metals Based on Flux Model in Pearl River Delta Economic Zone (China)

A Study of Prediction and EarlyWarning Forecast on Geochemical Accumulation of Soil Heavy Metals Based on Flux Model in Pearl River Delta Economic Zone (China)

A new assessment method for urbanization environmental impact: urban environment entropy model and its application

The thermodynamic law is one of the most widely used scientific principles. The comparability between the environmental impact of urbanization and the thermodynamic entropy was systematically analyzed. Consequently, the concept "Urban Environment Entropy" was brought forward and the "Urban Environment Entropy" model was established for urbanization environmental impact assessment in this study. The model was then utilized in a case study for the assessment of river water quality in the Pearl River Delta Economic Zone. The results indicated that the assessing results of the model are consistent to that of the equalized synthetic pollution index method. Therefore, it can be concluded that the Urban Environment Entropy model has high reliability and can be applied widely in urbanization environmental assessment research using many different environmental parameters.

Assessing Impact of Urbanization on River Water Quality In The Pearl River Delta Economic Zone, China

The Pearl River Delta Economic Zone is one of the most developed regions in China. It has been undergoing a rapid urbanization since the reformation and opening of China in 1978. This process plays a significant impact on the urban environment, particularly river water quality. The main goal of this present study is to assess the impact of urban activities especially urbanization on river water quality for the study area. Some Landsat TM images from 2000 were used to map the areas for different pollution levels of urban river sections for the study area. In addition, an improved equalized synthetic pollution index method was utilized to assess the field analytical results. The results indicate that there is a positive correlation between the rapidity of urbanization and the pollution levels of urban river water. Compared to the rural river water, urban river water was polluted more seriously. During the urban development process, urbanization and urban activities had a significant negative impact on the river water quality.

Dissolved trace elements in river water: spatial distribution and the influencing factor, a study for the Pearl River Delta Economic Zone, China

Twenty-nine water samples were collected from different river channels of the Pearl River Delta Economic Zone, China. An inductively coupled plasma-mass spectromonitor (ICP-MS) was used to measure concentrations of the trace elements in these samples. The results suggest that the average concentrations of rare earth elements in river water show an increasing trend from the West River, the North River, the rivers of the Pearl River Delta, and the Shenzhen River to the East River. Relatively high concentrations of heavy metals appear in the East River, the rivers of the Pearl River Delta and the Shenzhen River, while the West River and the North River have relatively low heavy metal concentrations. Trace element concentrations in samples collected near urban or industrial areas are much higher than those of samples collected from distant areas, away from urban and industrial areas. After natural conditions, human activities have significant influence on the trace element concentrations in river water. This trace element concentration’s spatial distribution in the river water from the Pearl River Delta Economic Zone is actually an integrated effect of natural conditions and human activity.

Urbanization in the Pearl River Delta Economic Zone, China

The Pearl River Delta Economic Zone (PRDEZ) is one of the most vigorous economic regions in China, and even in the world. Since the economic reform and opening up to the outside world, PRDEZ has been undergoing rapid urban expansion. based on a large number of investigative data, three indices (expansion coefficient of urban land, harmonious coefficient between population and cropland, and benefit coefficient of urban land) were designed and used to discuss the interrelationships between urbanization, economy and land use. The results suggest that urbanization is not the main reason for a reduction in cropland in the study area. In contrast, urbanization has the following advantages: 1) Urbanization of the rural population favours the release of land from rural residential area; 2) Urbanization can help to improve the city's agglomeration effect in terms of both population and economy; 3) Urbanization can contribute to improving the degree of intensification of land use; and 4) Urbanization can help to improve land-use efficiency. Therefore, urbanization may be an effective way to solve the contradiction between 'more population and much less land' in the study area.