Characteristics of transfer zones under the influence of preexisting faults and regional stress transformation:Wenchang A subsag,Zhujiang River Mouth Basin,northern South China Sea

A transfer zone in rift basins preserves important information on regional tectonic evolution and plays significant roles in hydrocarbon accumulation.Based on the systematic analysis of 3D seismic data and hydrocarbon accumulation conditions,the geometry,kinematics,and reservoir control of a large synthetic overlapping transfer zone in the south of the Wenchang A subsag in the Zhujiang(Pearl)River Mouth basin were investigated.Results indicate that the development and evolution of the transfer zone was controlled by the interaction between pre-existing faults and regional stress transformation.The intense rifting of the main faults of the transfer zone controlled the development of source rocks and faultcontrolled slope break paleogeomorphology.The strike-slip overprint since the Oligocene is conducive to the formation of a large-scale fault-anticline trap,and the secondary faults in the transfer zone contribute to the hydrocarbon transportation.The conjugate intersection area of the NE-and NW-trending faults offers more opportunity for hydrocarbon migration and accumulation.

Spatial and Temporal Variations of Pneumoconiosis in the Pearl River Delta Region in 2006–2015

Pneumoconiosis is a restrictive lung disease mostly caused by occupational exposure to dust,including silica dust,asbestos,and other fibers.Inhalable particles smaller than 10μm can enter the bronchioles,injure lung cells,and induce lung fibrosis.This hard-to-cure disease places a substantial burden on patients and society[1].

Legislation on protection of drinking water sources and local management practices in the Pearl River Delta region of China

The protection of drinking water sources is vital to urban development and public health.In this study,the current situation of the mandatory protection area for drinking water source in the Pearl River Delta region was investigated using a method combining Google Earth with the field survey.The gaps between management practices and legislation requirements were analyzed.Finally,several countermeasures for water resource protection were proposed as follows:to promote delineation in a more scientific way,to safeguard the sanctity of the law,to make better plan on water saving,and to encourage public participation in supervision and management.

Regional Evaluations of the Meteorological Drought Characteristics across the Pearl River Basin, China

Regional evaluation of drought characteristics provides critical information for water resource management. In this case, this study attempts to analyze the probability behaviors of drought events of a given severity in the Pearl River Basin and to construct severity-area-frequency curves of drought events. Due to possible impacts of complicated topographical properties and diverse climate types within the Pearl River Basin, the entire Pearl River Basin is subdivided into different homogeneous regions. In general, the Pearl River Basin can be categorized into four homogeneous regions, and the severity-area-frequency analysis results for the short-, medium- and long-term drought episodes within each homogeneous regions indicate stressful challenge for the water resource management in the Pearl River Basin due to the fact that severe droughts usually occur over the entire Pearl River Basin. Meanwhile, the Pearl River Delta will face a higher risk of drought when compared to other regions of the Pearl River Basin in terms of the medium-term drought. The Pearl River Basin is highly economically development and is heavily populated, thus impacts of droughts and related resilience resolutions or policies should be taken into account in the formulation of regional sustainable development of water resources and socio-economy within the Pearl River Basin, China.

Aerosol Optical Properties and Radiative Impacts in the Pearl River Delta Region of China during the Dry Season

Aerosol optical properties and direct radiative effects on surface irradiance were examined using seven years （2006-2012） of Cimel sunphotometer data collected at Panyu--the main atmospheric composition monitoring station in the Pearl River Delta （PRD） region of China. During the dry season （October to February）, mean values of the aerosol optical depth （AOD） at 550 nm, the Angstrom exponent, and the single scattering albedo at 440 nm （SSA） were 0.54, 1.33 and 0.87, respectively. About 90% of aerosols were dominated by fine-mode strongly absorbing particles. The size distribution was bimodal, with fine-mode particles dominating. The fine mode showed a peak at a radius of 0.12 μm in February and October （- 0.10 μm3 μm-2）. The mean diurnal shortwave direct radiative forcing at the surface, inside the atmosphere （FATM）, and at the top of the atmosphere, was -33.4± 7.0, 26.1 ± 5.6 and -7.3 ±2.7 W m-2, respectively. The corresponding mean values of aerosol direct shortwave radiative forcing per AOD were -60.0 ±7.8, 47.3 ± 8.3 and -12.8 ±3.1 W m-2, respectively. Moreover, during the study period, FATM showed a significant decreasing trend （p 〈 0.01） and SSA increased from 0.87 in 2006 to 0.91 in 2012, suggesting a decreasing trend of absorbing particles being released into the atmosphere. Optical properties and radiative impacts of the absorbing particles can be used to improve the accuracy of inversion algorithms for satellite-based aerosol retrievals in the PRD region and to better constrain the climate effect of aerosols in climate models.

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.

A SYSTEMATIC STUDY ON LAND AND REGIONAL DEVELOPMENT OF THE TARIM RIVER DRAINAGE BASIN,XINJIANG PROVINCE,CHINA

A Systematic Study on Land (SSL), aiming at the investigation of the land complex, isone of the important parts of integrated physical geography. With systematic theory as guid-ance, the dissertaton carries out the comprehensive and systematic study of a series ofsubsystems like land classification, land structure analysis, comprehensive physicalregionalization, land evaluation, reasonable planning of land utilization as well as popula-

The regional nature of nitrate-dominant haze pollution during autumn over the Pearl River Delta area

China has experienced severe haze and visibility degradation problems in recent years because of rapid urbanization and industrialization.In this study,daily atmospheric fine-aerosol samples were concurrently collected at three sites over the Pearl River Delta(PRD)region during 1–29 October 2014.PM2.5 samples were analyzed for organic carbon and elemental carbon using a thermal/optical carbon analyzer.Major water-soluble inorganic ions including F−,Cl−,NO3−,SO42−,Na+,NH4+,K+,Mg2+,and Ca2+were analyzed by ion chromatography.The results show that the temporal variations of PM2.5 concentration at the three sites were highly parallel,with particle pollution events simultaneously observed during 13–19 October(EP1)and 23–27 October(EP2),suggesting that pollution events in the PRD region are usually regional.This can most likely be attributed to the significant influences of synoptic conditions,which regionally facilitate or block diffusion of air pollutants.The chemical compositions of PM2.5 at the three sites were also found to be similar,dominated by organics and sulfates.The results indicate that accumulation of traffic emissions seems to play important roles in particle pollution for the PRD region,leading in this case to elevated nitrate contributions during both EP1 and EP2 at the three sites.Moreover,the authors found that locally emitted aerosols from biomass burning only markedly influenced the air condition at one site,Nanhai,during EP1,while regionally transported biomass burning aerosols from eastern and northern Guangdong Province influenced all three sampling sites when the PRD was dominated by polluted air from these directions during EP2.

FUTURE CHANGE OF PRECIPITATION EXTREMES OVER THE PEARL RIVER BASIN FROM REGIONAL CLIMATE MODELS

Based on RegCM4,a climate model system,we simulated the distribution of the present climate(1961-1990)and the future climate(2010-2099),under emission scenarios of RCPs over the whole Pearl River Basin.From the climate parameters,a set of mean precipitation,wet day frequency,and mean wet day intensity and several precipitation percentiles are used to assess the expected changes in daily precipitation characteristics for the 21 st century.Meanwhile the return values of precipitation intensity with an average return of 5,10,20,and 50 years are also used to assess the expected changes in precipitation extremes events in this study.The structure of the change across the precipitation distribution is very coherent between RCP4.5 and RCP8.5.The annual,spring and winter average precipitation decreases while the summer and autumn average precipitation increases.The basic diagnostics of precipitation show that the frequency of precipitation is projected to decrease but the intensity is projected to increase.The wet day percentiles(q90 and q95) also increase,indicating that precipitation extremes intensity will increase in the future.Meanwhile,the5-year return value tends to increase by 30%-45%in the basins of Liujiang River,Red Water River,Guihe River and Pearl River Delta region,where the 5-year return value of future climate corresponds to the 8-to 10-year return value of the present climate,and the 50-year return value corresponds to the 100-year return value of the present climate over the Pearl River Delta region in the 2080 s under RCP8.5,which indicates that the warming environment will give rise to changes in the intensity and frequency of extreme precipitation events.

THE REGIONAL DEVELOPMENT IN THE PEARL RIVER DELTA IN NEW TERM

Since China opening to outside world,the economy in the Pearl(Zhujiang)River Delta(PRD)has been dou-ble digit growth.It has been known as one of mature fast growth areas in the world and become the model and hope of Chi-nese reformand opening to outside wo rld.The regional development in PRD is the outcome of polarization effects .The polar-ization effects actually are extension of international regional divis ion and a combination of Hongkong’s i nfluence and re-form and open-door policies on the ma inland.Since the 1990s,driven by knowledge-based economy,the PRD has f urther adjusted the industrial structure a nd achieved good progress in upgradi ng industrial structure.Its high te chnology industry has developed quickly and the econom ic internationalization has deepen ed,meanwhile,the region is going th rough transforma-tion and some new trends have begun to appear,which include:university t owns springing up,industrial globalization and the construction of Hi-tech develop ment zones.The paper suggests that w ith the economic growth changing fro m relying on the low level production elements to relying on high level production ele ments,the regional policies in Guan gdong Province should develop correspondingly:1)make a plan to prohibite the blind con struction in innovative spatial con struc-tions;2)make measures to attract the overseas talents to establish a pool of talen t;3)work out the favorable policies for absorbing larger capital;4)formulate the policy of attracting a cluster of industries to speed up the upgrade of industrial development.

Assessment of Spatial Distribution and Submerged Scope for Storm Surge in the Pearl River Delta Region

The aim of this study was to explore the spatial distribution and submerged scope for storm surge in the Pearl River Delta(PRD) region.Based on the data of storm surges in the PRD region in the past 30 years,the return periods of 12 tide-gauge stations for storm surges were calculated separately with the methods of Gumbel and Pearson-III.The data of another six tide-gauge stations in Guangdong Coast was quoted to depict the overall features of storm surges in Guangdong.Using least-square method,the spatial distribution models of storm surges in different return periods were established to reveal the distribution rule of the set-up values of storm surges.The spatial distribution curves of storm surges in different return periods in the PRD Region were drawn up based on the models and the terrain of Guangdong Coast.According to the curves,the extreme set-up values of storm surges in 1 000,100,10 a return periods were determined on each spot of Guangdong Coast.Applying the spatial analysis technology of ArcGIS,with the topography data of the PRD Region,the submerged scopes of flood caused by storm surge in 1 000,100,10 a return periods were drawn up.The loss caused by storm surges was estimated.Results showed that the storm surges and the topography of PRD region jointly led to the serious flood in the PRD region.This assessment would be useful for the planning and design department to make decision and provide government scientific basis for storm surge prediction,coastal engineering designing and the prevention of storm surge disaster.

Annual Fluxes of Heavy Metal Elements in Atmospheric Dry and Wet Depositions in the Pearl River Delta Economic Region, Guangdong Province

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.

Spatial Structure and Land Use Control in Extended Metropolitan Region of Zhujiang River Delta,China

The Zhujiang (Pearl) River Delta is one of the most developed Extended Metropolitan Regions (EMR) in China.With the rapid urbanization,the agglomeration of population and industries has emerged,which has led to dramatic changes of spatial structure and land use in this region.With data of high resolution TM remote sensing images and Google Earth maps,this paper identified and analyzed the spatial pattern of the Zhujiang River Delta EMR using Envy and ArcGIS tools.It was found that 1) the industrial land uses were expanding substantially,particularly on the bank sides of the Zhujiang River estuary;2) large-scale housing developments were concentrated in the fringe of metropolitan areas such as those of Guangzhou and Shenzhen;3) a regional transportation network with the spatial pattern of ″1 circle +2 pieces + 3 axes″ had significantly affected the location choice of manufacture enterprises.At the same time,both highly specialized land use and severely mixed land use patterns were identified.As a consequence of the latter,land use efficiency of the whole EMR areas was reduced.Moreover,ecologic and environmental problems were severe.Based on the above analysis,suggestions were given from the viewpoint of spatial safety,land use efficiency,and the reorganization of spatial structure in the Zhujiang River Delta EMR.

Local Area Quotas for Industrial Emissions along Reaches of the Pearl River in Guangdong

There is an obvious departure from the regional equi-librium of developments between the upper and lower reaches of the Pearl River in Guangdong, which resulted in "the effects of contra-geography-grads development". It is mainly because the upriver mountainous areas have been deeply stuck in industriali-zation delay and marginalization plights, so that nearly 40 million local people have conceived a dream to get rid of "the vicious circle of poverty" by speeding up industrial development. But the problem is that such industrialization efforts on a large scale in mountainous areas are encountering the bottleneck of environ-mental capacity that strictly limits industrial emissions along the upper reaches of any water system. As a solution, an institutional arrangement called "the Local Area Quotas for Industrial Emis-sions along the Pearl River" is put forward supposed to give cor-responding compensation to the rights of industrial development yielded by some areas with lower environmental capacity through the distribution and trading of IDQs.

FORGING ASIA′S GLOBAL TRANSPARK IN THE PEARL RIVER DELTA AT ZHUHAI

The main purpose of the paper is to introduce the concept of the Global TransPark (GTP). It is a critical time to develop air logistics infrastructure in the New Economy. The paper also presents a brief review of the air cargo industry in the Asian-Pacific region and China,in particular China’s development in the industry as its economy has grown rapidly and globalized in the past two decades. The paper argues that China needs to develop a GTP to support its future growth,and explains why the Pearl River Delta-Hong Kong-Macao city-region or Extended Metropolitan Region (EMR) is the best location. Finally,it proposes that Zhuhai Airport,one of the five airports in the EMR,is the best site for the GTP. New policies from Chinese government as well as close cooperation between local governments of Guangdong and the two Special Administrative Regions of Hong Kong and Macao will be needed to make the establishment of the GTP possible.

Materializing the “Urban Region” Concept by Integrating Ecological Networks and Central Place Theory

This paper attempts to integrate urban development and ecological conservation by applying and syncretizing the “urban region” concept from landscape ecology and the “city-region” concept from socioeconomics. First, various concepts pertaining to regions are discussed and then, the integration of ecological conservation and urban development on a regional scale is introduced. Subsequently, the Greater Pearl River Delta, in China, is used as a case study area and landscape ecology’s “urban region” concept is applied to produce a landscape spatial arrangement framework for an urban region. This framework is achieved through the following steps: conceiving the study area as a region that consists of two urban regions, arranging ecological conservation landscapes by establishing a regional ecological network within the urban-region rings;and formulating an urban development strategy using central place theory. The resulting landscape spatial arrangement solution includes natural protection areas that cover half of the study area, several key strategic urbanizing locations, and suggestions for the strict protection of certain agricultural land-use areas. We believe that this framework facilitates a feasible exploration of land-use planning on a regional scale, although more in-depth studies are required to refine this approach.

Spatial Agglomeration of Exhibition Enterprises on a Regional Scale in China

During the past two decades, the exhibition industry in China has been developing rapidly and has become an important part of the modern service industry, particularly the agglomeration characteristics of exhibition enterprises highlighted on the regional scale. Although the development of theoretical research on the western exhibition industry has taken place over time, the spatial perspective has not been at the centre of attention so far. This paper aims to fill this gap and report on the agglomeration characteristics of exhibition enterprises and their influential factors. Based on data about exhibition enterprises in the Pearl River Delta(PRD) during 1991–2013, using the Ripley K function analysis and kernel density estimation, this research identifies that: 1) the exhibition enterprise on the regional scale is significantly characterized by spatial agglomeration, and the agglomeration density and scale are continuously increasing; 2) the spatial pattern of agglomeration has developed from a single-center to multi-center form. Meanwhile, this paper profiles the factors influencing the spatial agglomeration of exhibition enterprises by selecting the panel data of nine cities in the PRD in 1999, 2002, 2006 and 2013. The results show that market capacity, urban informatization level and exhibition venues significantly influence the location choice of exhibition enterprises. Among them, the market capacity is a variable that exerts a far greater impact than other factors do.

Ambient volatile organic compounds at a receptor site in the Pearl River Delta region:Variations,source apportionment and effects on ozone formation

We present the continuously measurements of volatile organic compounds(VOCs)at a receptor site(Wan Qing Sha,WQS)in the Pearl River Delta(PRD)region from September to November of 2017.The average mixing ratios of total VOCs(TVOCs)was 36.3±27.9 ppbv with the dominant contribution from alkanes(55.5%),followed by aromatics(33.3%).The diurnal variation of TVOCs showed a strong photochemical consumption during daytime,resulting in the formation of ozone(O_(3)).Five VOC sources were resolved by the positive matrix factorization(PMF)model,including solvent usage(28.6%),liquid petroleum gas(LPG)usage(24.4%),vehicle exhaust(21.0%),industrial emissions(13.2%)and gasoline evaporation(12.9%).The regional transport air masses from the upwind cities of south China can result in the elevated concentrations of TVOCs.Low ratios of TVOCs/NO_(x)(1.53±0.88)suggested that the O_(3) formation regime at WQS site was VOC-limited,which also confirmed by a photochemical box model with the master chemical mechanism(PBM-MCM).Furthermore,the observation on high-O_(3) episode days revealed that frequent O_(3) outbreaks at WQS were mainly caused by the regional transport of anthropogenic VOCs especially for aromatics and the subsequent photochemical reactions.This study provides valuable information for policymakers to propose the effective control strategies on photochemical pollution in a regional perspective.

Developing chemical signatures of particulate air pollution in the Pearl River Delta region, China

PM 2.5 samples were collected in a regional sampling network with three sites in Hong Kong and four sites in the adjacent inland Pearl River Delta （PRD） or Guangdong Province during four months/seasons from 2002–2003. Trans-boundary transport between Hong Kong and the inland PRD is inevitable under the influence of Asian monsoon. In summer, Hong Kong serves as the upwind site of the inland PRD while during other seasons it is under the influence of continental emissions. Previous studies have recognized the importance of using chemical signatures to differentiate local vs. regional contributions to air pollutants in Hong Kong such as the CO/NOx ratio, ratios of different VOC species. In this study, detailed chemical speciation by gas chromatography-mass spectrometry was performed with PM 2.5 samples to identify new chemical signatures to distinguish aerosols in Hong Kong from those from the inland PRD. Since Hong Kong is not influenced by the continental emissions from the inland PRD during summer, comparison focused on chemical data obtained from this season for chemical signatures. The new ratios developed from the current study include LCPI/HCPI ratio of alkanes （0.39 ± 0.02 in Hong Kong vs. 0.78 ± 0.08 in the inland PRD）, pyrene to benzo[ghi]perylene ratio （0.97 ± 0.21 in Hong Kong compared to 0.20 ± 0.06 in the inland PRD）, and the ratio of 1,2-benzenedioic acid to 1,4-benzenedioic acid （1.8 ± 0.1 in Hong Kong vs. 0.6 ± 0.05 in the inland PRD）. Results from this study also revealed that Hong Kong was impacted by ship emissions as reflected by substantially high V/Ni ratio （9 ± 2） while this ratio was about 1–2 at all sites in the inland PRD, which is very close to typical ratios from residual oil combustion.

Numerical Experiment Research of a Marine Fog Event in the Pearl River Estuary Region

A marine fog event that occurred near the Pearl River Estuary region on 26March 2002 was investigated with the fifth-generation Pennsylvania State University/National Centerfor Atmospheric Research Mesoscale Model (MM5). The results of numerical experiment are veryconsistent with the surface observations, especially in the processes of marine fog formation andevolution. Besides, a series of sensitivity numerical experiments were performed by varying thedistribution of landuse type and the turbulence exchange process. It is shown that the marine fogforms along the coastal line. Tests have indicated that when the distribution of landuse type ismodified, the regions where the marine fog can intrude into are obviously different. The turbulenceprocess in the model is important for fog formation and evolution. If the influence of turbulenceprocess is ignored in numerical simulation experiment, the simulated maximum of the cloud liquidwater content and the height of fog top will be decreased greatly.