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The national lockdown policies have drastically disrupted socioeconomic activities during the COVID-19 pandemic in China, which provides a unique opportunity to investigate the air quality response to such anthropogenic disruptions. And it is meaningful to evaluate the potential health impacts of air quality changes during the lockdown, especially for PM2.5 with adverse health effects. In this study, by using PM2.5 observations from 1388 monitoring stations nationwide in China, we examine the PM2.5 variations between the COVID-19 lockdown (February and March in 2020) and the same period in 2015-2019, and find that the national average of PM2.5 decreases by 18 μg m−3, and mean PM2.5 for most sites (about 75%) decrease by 30%-60%. The anthropogenic and meteorological contributions to these PM2.5 variations are also determined by using a stepwise multiple linear regression (MLR) model combined with the Kolmogorov-Zurbenko filter. Our results show that the change of anthropogenic emissions is a leading contributor to those widespread PM2.5 reductions, and meteorological conditions have the negative influence on PM2.5 reductions for some regions, such as Beijing-Tianjin-Hebei (BTH). Additionally, the avoided premature death due to PM2.5 reduction is estimated as a predicted number based on a log-linear concentration-response function. The total avoided premature death is 9952 in China, with dominant contribution (94%) from anthropogenic emission changes. For BTH, Yangtze River Delta, Pearl River Delta and Hubei regions, the reductions of PM2.5 are 24.1, 24.3, 13.5 and 29.5 μg m−3, with the avoided premature deaths of 1066, 1963, 454 and 583, respectively., Graphical abstract Image, graphical abstract

The Outline of the Development Plan (ODP) for the Guangdong-Hong Kong-Macao Greater Bay Area, (a region formerly know n as the Pearl River Delta – PRD – or the ‘world’s factory’) marks China’s dete...

Unlock the secrets of the Pearl River Delta's future in the post-COVID era with this must-read paper. Discover how PRD businesses are overcoming challenges and adapting to the new normal, with a focus on the electronics, machinery, and chemicals industries. Learn how the Chinese government's "Dual Circulation" strategy is creating exciting new opportunities for PRD foreign trade enterprises. Don't miss out on the market prospects that await - click here to read and download now! Sun, P., & Zuo, X. (2023). Navigating the Post-COVID Market: A Prospective Analysis of Foreign Trade in the Pearl River Delta, China. Journal of Scientific Reports, 5(1), 8-14., {"references":["Sun, P., & Zuo, X. (2023). Navigating the Post-COVID Market: A Prospective Analysis of Foreign Trade in the Pearl River Delta, China. Journal of Scientific Reports, 5(1), 8-14."]}

An urban agglomeration is the engine of regional and national economic growth, but also causes many ecological and environmental issues that emerge from massive land changes. In this study, the spatiotemporal evolution of an urban agglomeration was quantified and its impacts on the urban and regional landscape patterns were evaluated. It showed that the urbanized land area of the Pearl River Delta Urban Agglomeration (PRDUA) in China nearly quadrupled, having linearly increased from 1819.8 km2 to 7092.2 km2 between 1985 and 2015. The average annual growth rate presented a bimodal wave-like pattern through time, indicating that the PRDUA has witnessed two rounds of the urbanization process. The growth modes (e.g., leapfrog, edge-expansion, infilling) were detected and they exhibited co-existing but alternating dominating patterns during urbanization, demonstrating that the spatiotemporal evolution of the urban development of the PRDUA follows the “spiral diffusion-coalescence” hypothesis. The morphology of the PRDUA presented an alternating dispersal-compact pattern over time. The city-level and regional-level landscape patterns changed synchronously with the spatiotemporal evolution of the PRDUA over time. The urbanization of the PRDUA increased both the complexity and aggregation of the landscape, but also resulted in an increasing fragmentation and decreasing connectivity of the natural landscape in the Pearl River Delta region. These findings are helpful for better understanding how urban agglomerations evolve and in providing insights for regional urban planning and sustainable land management. Natural Science Foundation of China National Key R&D Program of China China Postdoctoral Science Foundation Joint-PhD project of Shanghai Jiao Tong University and The University of Melbourne

Green innovation is the technological innovation under the premise of environmental protection, energy conservation and emission reduction. Both technological innovation and green development need a lot of financial support. Does financial development effectively support the promotion of green innovation? This article selects 2009- 2018 panel data of nine cities in the Pearl River Delta and uses the non-radial direction distance function (NDDF) method of Data Envelopment Analysis to measure their efficiency of green innovation. Then, we use the Tobit model to verify to the effects of financial development on green innovation. The results showed that the index reflecting financial development scale of the Pearl River Delta’s cities, there is significantly negative correlation between the number of financial institutions and green innovation; the number of practitioners in financial institutions, the proportion of fiscal expenditures on science and technology, energy saving and environmental protection in total expenditures showed an evidently positive correlation between them. It indicates that financial development of the nine cities is good for the improvement of green innovation efficiency. Further, this paper uses substitution variables to conduct robustness test, and the above conclusions are still valid.

Nowadays, the Expansion and evolution of the global financial system oblige lenders to develop stricter requirements for assessing creditworthiness of borrowers. This paper analyses the problems prevalent in the existing credit models of coastal cities in China Pearl River Delta, including data centralization, difficulties in detecting forged data and delay in data transmission; we constructed a CDDC model based fuzzy sets that employs all the issues. The related results showed that the technology fuzzy sets decentralizes and expands data sources, acquires and processes data automatically and self-perfects its ability to rank borrowers into cohorts of creditworthiness. Moreover, the CDDC model out-performs the traditional model in assessing creditworthiness and reducing delinquencies and defaults. That means our fuzzy sets model employs decentralized data sources, destroys historical data regularly and facilitates training and improvement. It ranks creditworthy borrowers in a better fashion than the statistics-based traditional credit model.

We present a high-resolution shear-wave velocity model of the upper-middle crust beneath the Pearl River Delta. The sedimentary basins are characterized by low-velocity anomalies at depths of 6–8 km and reflect the lateral migration of the deposition centers. High-velocity structures are located predominantly in Hong Kong, and outline the supervolcano conduit and magma reservoir in the crust. We observe contrasting velocity structures across the Lianhuashan fault zone (LFZ) where low-velocity anomaly zones (LVZs) are developed in different strikes. Microseismic swarms at depths of 8–16 km mainly occurred at the intersection of the LVZs. Metamorphic fluids and migration in the crust are proposed to interpret the seismic activity. The intersecting LVZs would increase the lithologic permeability to allow deep-rooted fluids to flow up, whereas the overlying high-velocity structures representing the overflowing magma act as a permeable barrier that confines the seismicity in the middle-lower crust. We anticipate that the detailed subsurface structures will help correlate magmatic remnants with the distribution of intraplate earthquakes and assess the earthquake risks in the Greater Bay Area of China.

In order to investigate the pollution status of polycyclic aromatic hydrocarbons (PAHs) in the agricultural soil, 240 agricultural soil topsoil samples were collected from nine Pearl River Delta cities from June to September 2019. In addition, 72 samples were collected for vertical soil profiles, which soil profiles were excavated to a depth of 80 cm. After sample preparation, GC-MS was used for the separation of compounds on a HP-5MS quartz capillary column. ArcGIS software was used to map the spatial distribution. Health risk assessment was conducted using USEPA standard. The results showed that the total concentration of 16 PAHs ranged from 43.4 to 5630 ng/g, with an average of 219 ng/g. The spatial distribution showed that most of the seriously polluted areas were in the coastal area, near the port, and there was point source pollution in the Gaoming of Foshan. Vertically distributed display Zhuhai, Jiangmen, Zhaoqing, Shenzhen and Dongguan increased and then decreased from bottom to bottom, showing a low-high-low pattern, the concentration of PAHs in Zhongshan and Foshan decreased with the soil depth, while the concentration of PAHs in Guangzhou and Huizhou was enriched with human activities. The PAHs components in soil samples were mainly medium and high rings (4–6 rings). The analysis of the origin of PAH in soil samples showed that the mixture of incomplete combustion sources of fossil fuels such as coal and biomass and traffic emission sources were the main sources of soil PAHs. A small amount can be attributed to oil sources such as oil spills. The human health risk assessment showed no cancer risk for children, while for adults, may cause a potential risk of cancer, which needs to be noticed. Spearman correlation analysis showed that PAH content was significantly correlated with SOC (p < 0.01) and pH (p < 0.05). Port transport, road emissions and industrial production make the area a pollution hot topic, and supervision should be strengthened to protect the environment and food safety.

The accurate measurement of CO2 emissions is helpful for realizing the goals of “carbon neutralization” and “carbon peak”. However, most current research on CO2 emission measurements utilizes the traditional energy balance coefficient and top-down methods. The data granularity is large, and most studies are concentrated at the national, provincial, municipal, or district/county administrative unit scale. As an important part of the Guangdong–Hong Kong–Macao Greater Bay Area of China, the Pearl River Delta region has good nighttime light vitality and faces huge carbon emission pressure. Using the Pearl River Delta as the research area, this study constructed an optimized pixel-scale regression model based on NPP-VIIRS (The Visible Infrared Imaging Radiometer Suite on the Suomi National Polar-Orbiting Partnership spacecraft) nighttime light data and CO2 emissions data at the district and county levels for 2017. In addition, the spatial pattern of CO2 emissions in the Pearl River Delta was analyzed based on the predicted CO2 emission status. The results showed that the spatial pattern of CO2 emissions in the Pearl River Delta had the distinct characteristics of the “center-edge” effect, the spatial spillover effect, and high-value aggregation, which should be considered when making related social or public decisions.

In the context of happiness industry, this paper constructs the input-output index system of tourism industry efficiency, uses DEA model and Malmquist model to measure the tourism industry efficiency and its temporal-spatial evolution of nine cities in Pearl River Delta from 2010 to 2016, and uses Grey relational model to analyze the influencing factors.The results show that, the overall tourism industry efficiency in Pearl River Delta reaches a relatively high level; the overall efficiency and technical efficiency showed a descending trend from inside out with the Pearl River Estuary economic circle as the core. The scale efficiency of tourism industry in Pearl River Delta showed a good trend, and the tourism elements input could satisfy the livelihood needs to a great extent. The total factor productivity of most cities in Pearl River Delta shows a growing trend, but the change trend differs in different areas. Impact of influencing factors of tourism industry efficiency differs in cities of different development degree and the impact of social benefit and environmental benefit indicators on tourism industry efficiency increases significantly. Based on the construction of happiness industry, cities in Pearl River Delta should take effective measures to improve the tourism industry efficiency.

To reveal the pollution status of agricultural soils along with rapid urbanization and economic growth, a large regional survey of organochlorine pesticides (OCPs) in agricultural soils was conducted in the Pearl River Delta (PRD) of China. The results showed that the total residues of 23 OCPs were in the range of ND-946 ng/g dry weight. OCP residues showed distinct spatial distribution characteristics within the PRD. OCPs were mainly found in areas with high agricultural production and industrial activities. Higher OCP concentrations were observed in the top layer of soil, while the concentration decreases to marginal levels when the soil depth is greater than 50 cm. OCPs are mainly derived from historical use. Hexachlorocyclohexanes (HCHs) in the top soil of the study area are mainly from the use of lindane. Soil pH was negatively and significantly correlated with total OCP concentration. The human health risk assessment showed no health risk for children, while for adults, there is a non-carcinogenic risk, which needs to be noticed. Agricultural activities and industrial production have made the region a pollution hotspot and should arouse more stringent regulation to protect the environment and food safety.

Objectives To analyse the patterns of transition of health burden for 110 causes of death by stratification of age, sex and geographic regions in Guangdong between 2005 and 2015. Methods We analysed the age-specific, sex-specific, region-specific mortality in Guangdong based on assembled databases. County-level surveillance data were calculated to inform city-level changes. Results The age-standardised mortality of all causes, non-communicable diseases (NCDs), communicable diseases, maternal diseases, neonatal diseases, malnutrition and injury declined progressively. Despite declining mortality of NCDs, the overall burden of disease was dominated by NCDs (ie, cerebrovascular disease, chronic obstructive pulmonary disease) that still accounted for 86.93% and 88.12% of death in 2005 and 2015, respectively. Considerable variations across geographic regions were observed (lowest in Pearl River Delta and highest in west Guangdong). There was a modest shift to transport injuries at younger ages and unintentional injuries in the elderly. Conclusions We have documented a dramatic change in the overall mortality and age-specific, sex-specific and cause-specific mortality in Guangdong province between 2005 and 2015. The significant burden of NCDs remains a major healthcare issue despite the notable progress in reducing mortality in Guangdong, China. Our findings highlight important unmet needs to refine healthcare services by taking into account the inequity of age, sex and geographic regions. Identification of the ‘treatable’ risk factors and improved disease surveillance should be continuously improved to minimised the overall and cause-specific mortality.

So much time, research and effort are expended in accurately developing virtual models of theatres, but what happens when they are completed? It is not automatically clear how one uses a virtual model for research to generate new knowledge about performance. Our research has recreated a series of theatres, which no longer exist, in virtual form in order to visualise elements of performance and the social relations that shape and are shaped by a theatre venue. These international theatres include the Rose in London from the late 1500s, the Bergen Theatre from 1850, the Queen’s Theatre in Adelaide from 1841, an itinerant bamboo theatre for performing Cantonese opera along the Pearl River Delta in China and a tent version used to house the same form in the goldfields of Victoria, and the showroom at the Stardust Hotel in Las Vegas built in the late 1950s. This article has two aspects: the first outlines our work with actors in workshops to explore how the spatial dynamics of the models can inform knowledge of acting traditions and audience response appropriate to each venue. The second explores some of the challenges of installing era-specific lighting and sound technology in several of the venue models.

Elucidation of the chemical components of airborne fine particulate matter (PM2.5) facilitates the characterization of atmospheric contamination sources and associated human exposure risks. In the present study, we employed a high-throughput analytical approach to investigate the abundance and distribution of 163 plastic additives in ambient PM2.5 collected from 94 different sites across the Pearl River Delta region, China. These chemicals are from six categories, including organophosphate esters (OPEs), phthalate esters (PAEs), PAE replacements, bisphenol analogues, UV stabilizers, and antioxidants. Ninety-three of them exhibited a detection frequency greater than 50% in PM2.5, while the combined concentrations of target plastic additives ranged from 610 to 49,400 μg/g (median: 3500 μg/g) across sites. By category, concentrations of PAEs (median: 2710 μg/g) were one to three orders of magnitude greater than those of other groups, followed by PAE replacements (540 μg/g) and OPEs (76.2 μg/g). Chemical-dependent exposure risks to PM2.5-bound plastic additives were characterized via the estimated daily intake and hazard quotient (HQ) approaches, which resulted in two different risk prioritization systems. Although the HQ approach suggested no or very low health concerns when considering individual chemicals, the complexity of co-concurrent chemicals in PM2.5 raises the concern on potential health risks from exposure to airborne particles and a cocktail of chemical components.

The Pearl River Delta metropolitan region is one of the most densely urbanized megapolises worldwide with high exposure to weather-related disasters such as storms, storm surges and river floods. Shenzhen megacity has been the fastest growing city in the Pearl River Delta region with a significant increase of resident population from 0.32 million in 1980 to 13.03 million in 2018. Being a flood-prone city, Shenzhen’s rapid urbanization has further exacerbated potential flood losses and forthcoming risk. Thus, evaluating the changes in its exposure from present to future is essential for flood risk assessment, mitigation and management purposes. The main objective of this study is to present a methodology to assess the spatio-temporal dynamics of flood exposure from present to future using high-resolution and open-source data with a particular focus on the built-up area. To achieve this, the SLEUTH model, a cellular automata-based urban growth model, was employed for predicting the built-up area in Shenzhen in 2030. An almost threefold increase was observed in total built-up area from 421 km2 in 1995 to 1166 km2 in 2030, with the 2016 built-up area being 858 km2. Built-up areas, both present (2016) and projected (2030), were then used as the land cover input for flood hazard assessment based on a fuzzy comprehensive evaluation model, which classified the flood hazard into five levels. The analysis indicates that the built-up area subjected to the two highest flood hazard levels will increase by almost 88% (212 km2) from present to future. The approach presented here can be leveraged by policymakers to identify critical areas that should be prioritized for flood mitigation and protection actions to minimize potential losses.

To tackle internal and external challenges, the Chinese government has made great efforts to promote economic upgrading, but little scholarly attention has been paid to its social consequences. Pre...

The contributions of divergent and rotational wind components to the kinetic energy budget during a record-breaking rainstorm on 7 May 2017 over South China are examined. This warm-sector extreme precipitation caused historical maximum of 382.6 mm accumulated rainfall in 3 h over the Pearl River Delta (PRD) regions in South China. Results show that there was a high low-level southerly wind-speed tongue stretching into the PRD regions from the northeast of the South China Sea (SCS) during this extreme precipitation. The velocity potential exhibited a low-value center as well as a low-level divergence-center over the SCS. The rotational components of the kinetic energy (KR)-related terms were the main contribution-terms of the kinetic energy budget. The main contribution-terms of KR and the divergent component of kinetic energy (KD) were the barotropical and baroclinic processes-related terms due to cross-contour flow and the vertical flux divergence.

Sunshine duration (SD) has recently received a great deal of attention as it relates to climatic research under global climate change. Here, we explored the spatiotemporal variability of SD in the Pearl River Delta (PRD) in mainland China during 1960-2018. A novel equation was proposed to assess the relative influence of 5 climatic variables on variability in SD based on random forest (RF) analysis. The dominant variables, their temporal evolution driving SD, and their spatial distribution are discussed. Results showed that SD in the PRD varied significantly, both at a temporal and spatial scale. At the spatial scale, SD decreased gradually from the southeast to the northwest; in most areas, SD exhibited a downward trend. Temporally, annual SD decreased significantly at a rate of 57.01 h decade-1 during 1960-2018 (p < 0.01), suggesting a continuous dimming; an abrupt change occurred in 1981 with a main oscillation period of 3.0 yr. The annual mean SD showed a positive correlation with wind speed (WS) and a negative correlation with the other 4 climatic variables. Precipitation was determined to be the most influential variable, with a relative influence rate of 34.46%. The relative influence rates of the 5 examined variables changed over time, and their spatial distribution demonstrated significant diversity across different regions. Aerosols were found to be a factor driving SD in the PRD, but could not completely explain the change in SD in recent years. These findings provide a reference for studying the spatiotemporal variability of SD and detecting its influencing factors in highly urbanized areas.

On 4 January 2020, an ML 3.5 earthquake occurred in the Pearl River Estuary (PRE) and was felt at a distance of more than 200 km. According to the China Earthquake Networks Center, this event has been the only M>3 earthquake within the PRE since 1900. The Guangdong–Hong Kong–Macau Bay Area (GHMBA) surrounding the PRE is one of China’s most critical financial circles, and coastal earthquake hazard has become an increasing concern. Investigating the source parameter and causative fault of this earthquake is helpful for seismic hazard estimation and mitigation in the GHMBA. In this study, we first determined the focal mechanism of the mainshock using the cut-and-paste method. We then used the sliding-window cross-correlation method to detect foreshocks and aftershocks before relocating the earthquakes. Finally, we conducted forward modeling to retrieve the rupture directivity of the mainshock, using waveforms of one aftershock as empirical Green’s functions. The results demonstrate that this earthquake was an Mw 3.7 strike-slip event, with a focal depth of 10 km. The rupture direction of the mainshock was 78°, consistent with the northeast-east-trending fault system in the region. The identified source fault confirmed a seismogenic segment of the northeast-east-trending fault system in the PRE, which is the primary source of seismic hazard in the area.

There are 158 sampling points to be set up in the Pearl River delta economic region. The collecting period is mostly one year, namely, from July 2007 to July 2008. The eight heavy metal elements of Cr, Ni, Cu, Pb, Zn, As, Hg, and Cd in 474 dry and wet deposition samples were tested in terms of the standard procedures. Their average annual fluxes have no obvious difference between dry deposition and wet deposition. So these elements might be at an equilibrium or quasi-equilibrium state between dry deposition and wet deposition.

Using visible and near-infrared (Vis-NIR) spectroscopy combined with partial least squares (PLS) regression, the rapid reagent-free analysis model for chromium (Cr) content in tideland reclamation soil in the Pearl River Delta, China was established. Based on Savitzky-Golay (SG) smoothing and PLS regression, a multi-parameters optimization platform (SG-PLS) covering 264 modes was constructed to select the appropriately spectral preprocessing mode. The optimal SG-PLS model was determined according to the prediction effect. The selected optimal parameters d, p, m and LV were 2, 6, 23 and 8, respectively. Using the validation samples that were not involved in modeling, the root mean square error (SEPV), relative root mean square error (R-SEPV) and correlation coefficients (RP, V) of prediction were 11.66 mg·kg-1, 10.7% and 0.722, respectively. The results indicated that the feasibility of using Vis-NIR spectroscopy combined with SG-PLS method to analyze soil Cr content. The constructed multi-parameters optimization platform with SG-PLS is expected to be applied to a wider field of analysis. The rapid detection method has important application values to large-scale agricultural production.

Huizhou, seated in the Pearl River Delta, is located at the intersection of the three main folk groups of Han Nationality of Guangdong. Owing to the different historical sources and the different terrain of the three main folk groups such as Hakka, Guangfu and Chaoshan in Huizhou, village configurations and dwelling morphology differ from each other. Due to the same big Han Nationality and similar climate and landform, they share similar landscape patches, and clan culture in ancestrals. Research work will help the public be aware of the value, which is an efficient way of traditional culture protection and development.

Global rivers act as a dominant transport pathway for land-based plastic debris to the marine environment. Organic pollutants (OPs) affiliated with riverine plastics can also enter the global oceans, but their amounts remain unknown. Microplastic (MP) samples were collected in a one-year sampling event from the surface water of the eight main riverine outlets in the Pearl River Delta (PRD), China, and analyzed for OPs affiliated with MPs, including 16 polycyclic aromatic hydrocarbons (PAHs), eight polybrominated diphenyl ethers (PBDEs), and 14 polychlorinated biphenyls (PCBs). The mean concentrations of MP-affiliated ∑16PAH, ∑8PBDE, and ∑14PCB were 2010 (range: 25-40,100), 412 (range: 0.84-14,800), and 67.7 (range: 1.86-456) ng g-1, respectively. Based on these and previous results, the annual riverine outflows of MP-affiliated OPs were 148, 83, and 8.03 g for ∑16PAH, ∑8PBDE, and ∑14PCB, respectively. Assuming that plastic debris of different sizes contained the same concentrations of the target pollutants as MPs, the mean riverine outflows of plastic-bound ∑16PAH, ∑8PBDE, and ∑14PCB were 6.75, 3.77, and 0.37 kg year-1, respectively, which were insignificant compared with the riverine outflows of OPs through riverine water discharge (up to hundred tons per year). Apparently, plastics are an insignificant carrier of riverine OPs to the coastal oceans.

Higher alkanes are a major class of intermediate-volatility organic compounds (IVOCs), which have been proposed to be important precursors of secondary organic aerosols (SOA) in the atmosphere. Accurate estimation of SOA from higher alkanes and their oxidation processes in the atmosphere is limited, partially due to the difficulty of their measurement. High-time-resolution (10 s) measurements of higher alkanes were performed using NO+ chemical ionization in proton transfer reaction time-of-flight mass spectrometry (NO+ PTR-ToF-MS) at an urban site in Guangzhou in the Pearl River Delta (PRD) and at a rural site in the North China Plain (NCP). High concentrations were observed in both environments, with significant diurnal variations. At both sites, SOA production from higher alkanes is estimated from their photochemical losses and SOA yields. Higher alkanes account for significant fractions of SOA formation at the two sites, with average contributions of 7.0 % ± 8.0 % in Guangzhou and 9.4 % ± 9.1 % in NCP, which are comparable to or even higher than both single-ring aromatics and naphthalenes. The significant contributions of higher alkanes to SOA formation suggests that they should be explicitly included in current models for SOA formation. Our work also highlights the importance of NO+ PTR-ToF-MS in measuring higher alkanes and quantifying their contributions to SOA formation.

Speciated characterization of Volatile Organic Compounds (VOCs), including oxygenated VOCs (OVOCs), from construction machinery and river ships in China is currently lacking. In this regard, we conducted field measurement on speciated VOC (including OVOC) emissions from six construction machinery and five river ships in the Pearl River Delta (PRD) region to identify VOC emission characteristics. We noticed that OVOC emissions from construction machinery and ships accounted for more than 50% of the total VOC emissions, followed by alkenes, aromatics and alkanes. Formaldehyde and acetaldehyde were the most emission species, accounting for 61.8%-83.2% of OVOCs. For construction machinery, the fuel-based emission factors of roller, grader and pile driver were 3.12, 3.12 and 7.36 g/kg, respectively. With the rigorous restraint by the national emission standards, VOC emissions of construction machinery had decreased considerably, especially during stage Ⅲ. Ozone formation potential was also significantly reduced due to the significant decrease in emissions of OVOCs and alkenes with higher reactivity. For river ships, the fuel-based emission factors of cargo ships and speedboat were 1.46 and 0.44 g/kg, respectively. VOC emissions from construction machinery and river ships in Guangdong Province in 2017 were 8851.0 and 4361.0 ton, respectively. This study filled the knowledge gaps of reactive gas emissions from different kinds of non-road mobile sources over the PRD, and more importantly, highlighted the necessity in adding OVOC measurement to give a complete and accurate depiction of reactive gas emissions from non-road mobile sources.

This study proposes a series of statistical and regression approaches to investigate city-cluster transport connectivity patterns. Three major city clusters in China are selected for this study, namely, the Beijing-Tianjin-Hebei (BTH), the Yangtze River Delta (YRD), and the Pearl River Delta (PRD) economic zones. Our analyses examine three aspects of city-cluster connectivity patterns: (i) connectivity distribution among cities within the city cluster; (ii) dependence of the non-center city on the center city; and (iii) the impact of improved intra-city-cluster rail connectivity on air-connectivity distribution. First, it is found that the BTH has the most concentrated connectivity among the three city clusters, with Beijing clearly dominating the other cities in every kind of connectivity. The connectivity distributions are more balanced in the YRD and PRD. Second, the calculated “survival connectivity” and regression analyses suggest that non-center cities heavily rely on the center city as the hub to develop their network connectivity. Such a “hub-and-spoke system” helps a non-center city improve total connectivity but reduces its direct connectivity to other cities outside the city cluster. Finally, our regression analysis shows that improved intra-city-cluster rail connectivity further deteriorates the air-connectivity disparity within the city cluster, which occurs because the center city benefits more from the upgraded air-HSR (high speed rail) intermodal connectivity because it can attract air passengers from neighboring non-center cities. Relevant policy implications and suggestions are also discussed in the paper. We believe the proposed statistical and regression approaches can be easily applied to examine city-cluster connectivity in other contexts and countries.

This article traces the Chinese accommodation of foreigners in the lower section of the Pearl River delta during the Opium War to the region’s social ecology in late imperial times. With a long tradition of living with foreign sojourners and their vessels, Chinese people in the delta congregated on an unprecedented scale at the outer anchorages within the present-day Hong Kong region in 1839–1841 to trade with Euro-American merchants and the British expedition. As mobile and violent provisioners and opium dealers, they flourished in the littoral borderland between the Qing and British empires. Their cross-shore ventures constituted an intensification of their prewar activities and an economic adaptive strategy in the competitive society of mid-Qing Guangdong. Centering on the socioeconomic lives of ordinary Chinese people, this article problematizes the usage of “Hanjian” and “collaboration” as nationalist and statist labels to summarize Chinese assistance to foreigners in times of external war in modern China.

Drawing on empirical data from interviews with young Chinese female rural–urban migrant workers in the Pearl River Delta of China’s Guangdong province, this article explores the ways in which physi...

Our survey data on migrant workers in the Pearl River Delta region from 2006 to 2010 and recent fieldwork show that the enactment of the Labor Contract Law encouraged both the signing of labor cont...

The monthly ground-level ozone (O3) concentrations in eastern China (EC) are estimated using the surface NO2 and CH2O concentrations derived from the ozone monitoring instrument (OMI) according to the geographically weighted regression (GWR) method. The accuracy assessment shows that the proposed GWR model performed well for estimating monthly O3 concentrations ( ${R} ^{2} =0.81$ , absolute error (AE) $= 7.38~\mu \text{g}/\text{m}^{3}$ for the fitted results, and ${R} ^{2}= 0.77$ , AE $= 8.20~\mu \text{g}/\text{m}^{3}$ ). The estimated yearly average O3 concentration is $56.20~\mu \text{g}/\text{m}^{3}$ , with a standard deviation of $3.68~\mu \text{g}/\text{m}^{3}$ in 2014 across EC. The O3 concentrations show great spatial variation, with hotspots extending from north-EC to the Yangtze River Delta and the Pearl River Delta. The monthly O3 concentrations are generally low during the cold season and high during the warm season, but local areas show different seasonal variations.

Mole fractions of atmospheric CO2 (XCO2) have been continuously measured from October 2014 to March 2016 at the Guangzhou Panyu Atmospheric Composition Site (23.00°N, 113.21°E; 140 m MSL) in the Pearl River Delta (PRD) region using a cavity ring-down spectrometer. Approximately 66.63%, 19.28%, and 14.09% of the observed values were filtered as background, pollutant source, and sink due to biospheric uptake, respectively, by applying a robust local regression procedure. Their corresponding mean values were 424.12 ± 10.12 ppm (×10−6 mol mol−1), 447.83 ± 13.63 ppm, and 408.83 ± 7.75 ppm. The background XCO2 levels were highest in spring and winter, moderate in autumn, and lowest in summer. The diurnal XCO2 was at a minimum from 1400–1600 LST (Local Standard Time) and a maximum at 0500 LST the next day. The increase of XCO2 in spring and summer was mainly associated with polluted air masses from south coastal Vietnam, the South China Sea, and the southeast Pearl River Estuary. With the exception of summer, airflow primarily from marine regions southeast of Taiwan that passed over the Pearl River Estuary had a greater impact on XCO2, suggesting an important potential source region.

The renovation of ancient buildings and roadways as well as the improvement of green landscape and sanitation facilities of historic villages are mainly based on the conservation planning in the Pe...

While scholars and activists often advocate using the term ‘sex worker’ in preference to prostitute, in my research I found that female prostitutes in the Pearl River Delta area, south China, do not like to be addressed as such, and prefer the title xiaojie in Chinese. ‘Sex worker’ generalises the heterogeneity of meanings these women identify and attribute to what they do; it does not capture the complex cultural meanings involved in the term xiaojie. It is stigmatising in that what is exchanged within the transaction is less defined by sexual acts and more by a diversified range of activities. The women employ what is useful to them and infuse new meanings in it to construct gender images and identities to resist the sex worker stigma and to express their desires as rural-to-urban migrants. Using xiaojie becomes a destigmatising and gender tactic. I also found that the women discard the idea of finding alternative jobs partly because of the practical difficulty, and partly because they do not want to work (gongzuo) any more in the future. This study highlights the importance of exploring desire and agency to understand the lived experiences of this particular group of women.

Stringent emission controls effectively brought down particulate mass concentrations by >30% in the North China Plain (NCP) and Pearl River Delta (PRD) regions. However, the low-visibility (

A simulation study of precipitation processes in summer over the Pearl River Delta region was conducted using the Weather Research and Forecasting Model coupled to with Chemistry, WRF-Chem. We investigated the influence of air pollution and aerosols on the summertime heavy precipitation over the subtropical regions. The study showed the following results. (1) The control test can simulate the largescale meteorological conditions and the mesoscale weather processes well. The chemistry module (CHEM) had only a small influence on the simulation of the macroscale environmental field. Simulations of mesoscale weather processes could be improved by including atmospheric chemistry modules and anthropogenic aerosols. (2) Even though air pollution and aerosols can reduce solar shortwave radiation received by the ground, they increase downward longwave radiation from the atmosphere. Heating atmosphere by aerosols may increase stability and suppress convection. However, aerosols suppress the conversion of cloud water into rainwater and cloud ice, restricting heavy precipitation by reducing the collision–coalescence process during strong precipitation. Aerosols extend the lifetime of clouds and increase cloud cover, contributing to maintaining the precipitation. (3) Indirect and direct aerosol effects have significantly different functions in precipitation. The direct effect primarily has a positive function on the formation of rainwater, while the indirect effect suppresses increases in the precipitation intensity and contributes to maintaining the precipitation. But the notable invigoration effect was not found.

This study investigated heavy frontal rainfall that occurred on 13–14 October 2011 over the Pearl River Delta (PRD) in China. The frontal rainstorm was simulated using the WRF-ARW Model (version 3.3), which included its urban canopy model. Although the model-simulated convection occurred 2 h early and the second precipitation peak was underestimated, the model represented the formation, development, and extinction of the frontal rainfall and captured the distribution of the peak value. In addition, the averaged value of 49.7 W m−2was taken as the anthropogenic heat flux (AHF) of the PRD, and two land-use datasets were adopted: one for 1992 and the other for 2011. The simulation revealed that AHF and urban land-use change (ULUC) increased the total rainfall over the PRD by 6.3% and 7.4% and increased the maximum hourly rainfall intensity by 24.6% and 21.2%, respectively. Furthermore, to elucidate the mechanism of AHF and ULUC influence, the rainstorm structure, low-level jet (LLJ), and CAPE of the rainfall event were analyzed. It was found that AHF and ULUC enhanced two strong southward LLJs located over the urban areas, which carried abundant water vapor to the PRD and generated additional upper-level CAPE. This not only sustained steady ascent of the air, but it also created conditions favorable for downward motion, resulting in large persistent convective clouds and heavy frontal rainfall.