Container ports and hinterland manufacturing are two important forces of the local participation in economic globalization.This study,taking the Pearl River Delta(PRD),China with an export-oriented economy as an examp...Container ports and hinterland manufacturing are two important forces of the local participation in economic globalization.This study,taking the Pearl River Delta(PRD),China with an export-oriented economy as an example,applies Huff and panel regres-sion models to evaluate the impact of hinterland manufacturing on the development of container ports during the period of 1993–2019.The results show that 1)the spatial patterns of hinterlands for hub ports help to determine the distribution range and scale of economic variables that affect port throughput;2)the hinterland’s gross manufacturing output has universally positive influence on port through-put,wherein export-oriented processing and the entire manufacturing industry have significantly positive impact on port throughput in 1993–2011 and 2001–2019,respectively;3)the two internal structural factors related to an export-oriented economy,labor-intensive sectors and foreign-funded terminals,have positively moderate the direct influence of hinterland manufacturing on port throughput.Our results highlight the importance of local context in understanding port-manufacturing relationship in developing economies.Based on our findings,policy implications are further proposed to enhance port network organization in PRD.展开更多
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-geoc...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.展开更多
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 s...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 13elements(Al, As, Cu, Cd, Co, Cr, Fe, Hg, Mn, Ni, Pb, Si,and Zn) and other parameters(p H 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.展开更多
In this paper, the online weather research and forecasting and chemistry (WRF-Chem) model is used to explore the impacts of urban expansion on regional weather conditions and its implication on surface ozone concent...In this paper, the online weather research and forecasting and chemistry (WRF-Chem) model is used to explore the impacts of urban expansion on regional weather conditions and its implication on surface ozone concentrations over the Pearl River Delta(PRD) and Yangtze River Delta(YRD) regions. Two scenarios of urban maps are used in the WRF-Chem to represent the early 1990s (pre-urbanization) and the current urban distribution in the PRD and the YRD. Month-long simulation results using the above land-use scenarios for March 2001 show that urbanization increases both the day- and night-time 2-m temperatures by about 0.6℃and 1.4℃, respectively. Daytime reduction in the wind speed by about 3.0 m s-1 is larger than that for the nighttime (0.5 to 2 m s-1). The daytime increase in the PBL height (〉 200 m) is also larger than the nighttime (50-100 m). The meteorological conditions modified by urbanization lead to detectable ozone-concentration changes in the PRD and the YRD. Urbanization increases the nighttime surface-ozone concentrations by about 4.7%-8.5% and by about 2.9%-4.2% for the daytime. In addition to modifying individual meteorological variables, urbanization also enhances the convergence zones, especially in the PRD. More importantly, urbanization has different effects on the surface ozone for the PRD and the YRD, presumably due to their urbanization characteristics and geographical locations. Even though the PRD has a smaller increase in the surface temperature than the YRD, it has (a) weaker surface wind speed, (b) smaller increase in PBL heights, and (c) stronger convergence zones. The latter three factors outweighed the temperature increase and resulted in a larger ozone enhancement in the PRD than the YRD.展开更多
Demographic and economic development can be seen as two sides of one coin in the process of regional development.This article deals with how economic and demographic changes influence the settlement structure and deve...Demographic and economic development can be seen as two sides of one coin in the process of regional development.This article deals with how economic and demographic changes influence the settlement structure and development of the Pearl River Delta(PRD)and lead to regionalization processes within the large agglomerations.The aim of the study was to understand the interrelation between the three aspects:economic change,demographic change and change of spatial structures.Based on population age and occupational data,spatial changes in demographic structure and economic activities from 2000 to 2010 were analyzed.It was found that the demographic and economic change reflected changing spatial patterns between the urban centers and the hinterland in the PRD.Two processes were apparent during the studied period in the hinterlands and the high-density areas of the PRD.On one hand,the hinterlands in the PRD attracted more manufacturing activities,while the inner high-density areas experienced a decrease in manufacturing,associated with an increase in young labor in regions where workplaces that only required limited education expanded.On the other hand,specialization in knowledge-intensive business services increased in the inner high-density areas,which also saw an increased share in the older population.This finding suggests that increasing knowledge-intensive work correlates with higher age structures due to the longer formal education required and also the benefits knowledge workers accrue through experience and gained knowledge over time.Therefore,based on a transformation process,we tentatively conclude that the populations in high-density areas in the PRD became more middle-aged and were represented by more knowledge workers.展开更多
<div style="text-align:justify;"> 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...<div style="text-align:justify;"> 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. </div>展开更多
In traditional urban geography, city contact research is a classic study element in city research. In general, researchers use the traditional gravity model to characterize the contacts that exist between two cities. ...In traditional urban geography, city contact research is a classic study element in city research. In general, researchers use the traditional gravity model to characterize the contacts that exist between two cities. The traditional gravity model assumes ideal conditions, but these preconditions and their results often do not exist in realistic conditions. Thus, we used a modified gravity model to characterize the city contacts within a specific region. This model considers factors such as intercity complementarities, government intervention, and the diversity of the transportation infrastructure which is characterized as the transportation distance instead of the traditional Euclidean distance. We applied this model to an empirical study of city contact in the Zhujiang(Pearl) River Delta(PRD) of China. The regression results indicated that the modified gravity model could measure city contact more accurately and comprehensively than the traditional gravity model, i.e., it yielded a higher adjusted R2 value(0.379) than the traditional gravity model result(0.259). Our study also suggests that, in addition to urban-regional and metropolitan development, the complementarities of the basic functions of cities at the administrative and market levels, as well as the corporeal and immaterial levels, play very significant roles in the characterization of city contact. Given the complexity of city contact, it will be necessary to consider more relevant influential factors in the modified gravity model to characterize the features of city contact in the future.展开更多
The Pearl River Delta (PRD) is located in the north coast area of the South China Sea (SCS). As one of the largest delta in China, only the two latest events among the several tens of eustatic fluctuations occurri...The Pearl River Delta (PRD) is located in the north coast area of the South China Sea (SCS). As one of the largest delta in China, only the two latest events among the several tens of eustatic fluctuations occurring in the Quaternary were recorded in almost whole area of the PRD.展开更多
Projections of potential submerged area due to sea level rise are helpful for improving understanding of the influence of ongoing global warming on coastal areas. The Ensemble Empirical Mode Decomposition method is us...Projections of potential submerged area due to sea level rise are helpful for improving understanding of the influence of ongoing global warming on coastal areas. The Ensemble Empirical Mode Decomposition method is used to adaptively decompose the sea level time series in order to extract the secular trend component. Then the linear relationship between the global mean sea level (GMSL) change and the Zhujiang (Pearl) River Delta (PRD) sea level change is calculated: an increase of 1.0 m in the GMSL corresponds to a 1.3 m (uncertainty interval from 1.25 to 1.46 m) increase in the PRD. Based on this relationship and the GMSL rise projected by the Coupled Model Intercomparison Project Phase 5 under three greenhouse gas emission scenarios (representative concentration pathways, or RCPs, from low to high emission scenarios RCP2.6, RCP4.5, and RCP8.5), the PRD sea level is calculated and projected for the period 2006-2100. By around the year 2050, the PRD sea level will rise 0.29 (0.21 to 0.40) m under RCP2.6, 0.31 (0.22 to 0.42) m under RCP4.5, and 0.34 (0.25 to 0.46) m under RCP8.5, respectively. By 2100, it will rise 0.59 (0.36 to 0.88) m, 0.71 (0.47 to 1.02) m, and 1.0 (0.68 to 1.41) m, respectively. In addition, considering the extreme value of relative sea level due to land subsidence (i.e., 0.20 m) and that obtained from intermonthly variability (i.e., 0.33 m), the PRD sea level will rise 1.94 m by the year 2100 under the RCP8.5 scenario with the upper uncertainty level (i.e., 1.41 m). Accordingly, the potential submerged area is 8.57x103 km2 for the PRD, about 1.3 times its present area.展开更多
A series of researches were carried out for the soil samples in the Pearl River Delta under the action of consolidation loads,such as the quantitative analyses of the pore scale,shape and size distributions of micro-s...A series of researches were carried out for the soil samples in the Pearl River Delta under the action of consolidation loads,such as the quantitative analyses of the pore scale,shape and size distributions of micro-structure units,with an environmental scanning electron microscope (ESEM),a mercury intrusion analyzer and a mineral diffractometer. The experimental results show that the consolidation pressures remarkably change the pore sizes and distribution characteristics of the silt,thus changing its compressibility and permeability. This can be proved by the fact that,in the earlier stage with a consolidation pressure of p<200 kPa,the pore sizes are greater and the compressibility and permeability coefficients are larger. However,they rapidly decrease with the increase in consolidation pressure. And in the later stage with a consolidation pressure of p>200 kPa,the pore sizes are smaller and the compressibility and permeability coefficients are less. Therefore,the empirical formulas of compression coefficient and permeability coefficient vs consolidation load and average pore diameter are deduced.展开更多
The growth of peripheral ports to dominant hubs has been well documented in North America and Europe,and has led to the elaboration of several theoretical models.However,although changes in containerization growth hav...The growth of peripheral ports to dominant hubs has been well documented in North America and Europe,and has led to the elaboration of several theoretical models.However,although changes in containerization growth have been taking place in the South and East Asia in recent years,particularly in China,only a few studies have fo-cused on this region.The Pearl(Zhujiang) River Delta(PRD) has a typical port system with hub and peripheral ports,and provides an excellent case for studying the Peripheral Challenge.This paper introduces the theoretical evidence of the Hayuth model and analyzes the evolution of the container port system in the PRD with five phases:1) phase I:preconditions for change and phase II:initial container port development in the 1970s and early 1980s;2) phase III:diffusion,consolidation,and port concentration in the middle and late 1980s;3) phase IV:the load center in the 1990s;and(4) phase V:the Peripheral Challenge since the late 1990s.The results illustrate that the Shenzhen port presents mounting challenges to the Hong Kong port,descending from a transshipment hub of China to a regional load center of Southeast China.Furthermore,this paper explores five points that have led to the evolution of the port system in the PRD:1) competition in the regional port systems;2) different interested parties;3) shift of investment strategies of in-ternational terminal operators;4) integration of shipping networks and reorganization of carriers;and 5) cost-based competition.展开更多
A reasonable coordination degree assessment of the social-economic development level and the resource-environment quality level are essential to ident the key factory of the development, and vital to determine the app...A reasonable coordination degree assessment of the social-economic development level and the resource-environment quality level are essential to ident the key factory of the development, and vital to determine the appropriate development strategy and achieve sustainable development. The major function oriented zoning plays a role in spatial coordination mainly' by spatial guidance and restriction, so. the proposal of major function oriented zoning gives a new train of thought to generate a coordination evaluation of economy-society and the resource-environment system, From the view of major function oriented zoning that considers resource environmental bearing capacity, existing development density and development potential, this paper constructs an index system and model of coordination evahtation with a case study on Pearl River Delta. The results have shown: (I) It can reveal the conflicts of economic-social development and resource-environment quality to ac- curately consider resource environmental bearing capacity, existing development densio~ and development po- tential; (2) The coordination degree between social-economy system and resource-environment system in Pearl River Delta continued to decline in the past 10 years. The spatial extent of coordination evoh,es.from coordina- tion in the whole Pearl River Delta to imbalance in the core areas, and at present, the uncoordinated areas have already diffused from core areas to the outlying regions: (3) Most regions of the Pearl River Delta are in uncoordinated condition When considering the coordination degree of economic-social development and resollrceenvironment quality, not as coordinated as some scholars considered.展开更多
Understanding essential for formulating the trends in PM2.5 levels is 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 (...Understanding essential for formulating the trends in PM2.5 levels is 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 SO24 show a similar trend, increasing before 2005 and then decreasing slightly. The annual average PM2.5 concentra- tion ranges from 49.1 μg·m-3 in 2000 to 64.3 μg·m-3 in 2010, with a peak of 84.1 μg· m3 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 SO2/4 are 13.0, 6.5, and 11.8μg·m-3, respectively. NO3 and NH+ respectively have concentrations of 1.5 μg·m-3 and 2.9 μg·m-3 in 2000 and 6.4 μg·m 3 and 5.3μg·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 SO2/4- 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.展开更多
As the Central Place Theory indicates, the centricity of a central city can influence the extension of its ser- vice. Since the service industry in the theory is mostly consumer services, it is worth studying the rela...As the Central Place Theory indicates, the centricity of a central city can influence the extension of its ser- vice. Since the service industry in the theory is mostly consumer services, it is worth studying the relationship between the producer services and the centricity of the city in the service society with producer services becoming a more im- portant part of the service industry. The paper takes the case of the Zhujiang (Pearl) River Delta (PRD), a developed region in China, to study the relationship between the developing level of producer services and the urban hierarchy. Based on the analysis about the spatial difference of the producer services in the nine cities of the PRD, and the divi- sion of the nine cities according to some economic indices, it is shown that there is a correlation between the develop- ing level of producer services and the urban hierarchy. Furthermore, two deductions about the future status of the pro- ducer services in the city and the location of the producer services in a large region can be made from this correlation between the developing level of producer services and the urban hierarchy.展开更多
基金Under the auspices of the National Natural Science Foundation of China(No.41930646)Guangdong Natural Science Foundation(No.2022A1515011572)。
文摘Container ports and hinterland manufacturing are two important forces of the local participation in economic globalization.This study,taking the Pearl River Delta(PRD),China with an export-oriented economy as an example,applies Huff and panel regres-sion models to evaluate the impact of hinterland manufacturing on the development of container ports during the period of 1993–2019.The results show that 1)the spatial patterns of hinterlands for hub ports help to determine the distribution range and scale of economic variables that affect port throughput;2)the hinterland’s gross manufacturing output has universally positive influence on port through-put,wherein export-oriented processing and the entire manufacturing industry have significantly positive impact on port throughput in 1993–2011 and 2001–2019,respectively;3)the two internal structural factors related to an export-oriented economy,labor-intensive sectors and foreign-funded terminals,have positively moderate the direct influence of hinterland manufacturing on port throughput.Our results highlight the importance of local context in understanding port-manufacturing relationship in developing economies.Based on our findings,policy implications are further proposed to enhance port network organization in PRD.
文摘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.
基金supported by the China Geological Survey Project (1212010511216)Environmental Protection Special Foundation of Guangdong Provincial (Guangdong Environment [2014]126)
文摘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 13elements(Al, As, Cu, Cd, Co, Cr, Fe, Hg, Mn, Ni, Pb, Si,and Zn) and other parameters(p H 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.
基金supported by the National Natural Science Foundation of China (Grant Nos. 40875076, U0833001, and40645024)the National Center for Atmospheric Research (NCAR) FY07 Director Opportunity Fund+2 种基金supported by the Knowledge Innovation Program of the Chinese Academy of Sciences (IAP 07306)the Institute of Atmospheric Physics, the Chinese Academy of Sciences(LAPC-KF-2006-12)the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry of China
文摘In this paper, the online weather research and forecasting and chemistry (WRF-Chem) model is used to explore the impacts of urban expansion on regional weather conditions and its implication on surface ozone concentrations over the Pearl River Delta(PRD) and Yangtze River Delta(YRD) regions. Two scenarios of urban maps are used in the WRF-Chem to represent the early 1990s (pre-urbanization) and the current urban distribution in the PRD and the YRD. Month-long simulation results using the above land-use scenarios for March 2001 show that urbanization increases both the day- and night-time 2-m temperatures by about 0.6℃and 1.4℃, respectively. Daytime reduction in the wind speed by about 3.0 m s-1 is larger than that for the nighttime (0.5 to 2 m s-1). The daytime increase in the PBL height (〉 200 m) is also larger than the nighttime (50-100 m). The meteorological conditions modified by urbanization lead to detectable ozone-concentration changes in the PRD and the YRD. Urbanization increases the nighttime surface-ozone concentrations by about 4.7%-8.5% and by about 2.9%-4.2% for the daytime. In addition to modifying individual meteorological variables, urbanization also enhances the convergence zones, especially in the PRD. More importantly, urbanization has different effects on the surface ozone for the PRD and the YRD, presumably due to their urbanization characteristics and geographical locations. Even though the PRD has a smaller increase in the surface temperature than the YRD, it has (a) weaker surface wind speed, (b) smaller increase in PBL heights, and (c) stronger convergence zones. The latter three factors outweighed the temperature increase and resulted in a larger ozone enhancement in the PRD than the YRD.
基金Under the auspices of the National Natural Science Foundation of China(No.41471107)。
文摘Demographic and economic development can be seen as two sides of one coin in the process of regional development.This article deals with how economic and demographic changes influence the settlement structure and development of the Pearl River Delta(PRD)and lead to regionalization processes within the large agglomerations.The aim of the study was to understand the interrelation between the three aspects:economic change,demographic change and change of spatial structures.Based on population age and occupational data,spatial changes in demographic structure and economic activities from 2000 to 2010 were analyzed.It was found that the demographic and economic change reflected changing spatial patterns between the urban centers and the hinterland in the PRD.Two processes were apparent during the studied period in the hinterlands and the high-density areas of the PRD.On one hand,the hinterlands in the PRD attracted more manufacturing activities,while the inner high-density areas experienced a decrease in manufacturing,associated with an increase in young labor in regions where workplaces that only required limited education expanded.On the other hand,specialization in knowledge-intensive business services increased in the inner high-density areas,which also saw an increased share in the older population.This finding suggests that increasing knowledge-intensive work correlates with higher age structures due to the longer formal education required and also the benefits knowledge workers accrue through experience and gained knowledge over time.Therefore,based on a transformation process,we tentatively conclude that the populations in high-density areas in the PRD became more middle-aged and were represented by more knowledge workers.
文摘<div style="text-align:justify;"> 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. </div>
基金Under the auspices of National Natural Science Foundation of China(No.41271177)Guangdong Natural Science Foundation(No.S2012010008902)
文摘In traditional urban geography, city contact research is a classic study element in city research. In general, researchers use the traditional gravity model to characterize the contacts that exist between two cities. The traditional gravity model assumes ideal conditions, but these preconditions and their results often do not exist in realistic conditions. Thus, we used a modified gravity model to characterize the city contacts within a specific region. This model considers factors such as intercity complementarities, government intervention, and the diversity of the transportation infrastructure which is characterized as the transportation distance instead of the traditional Euclidean distance. We applied this model to an empirical study of city contact in the Zhujiang(Pearl) River Delta(PRD) of China. The regression results indicated that the modified gravity model could measure city contact more accurately and comprehensively than the traditional gravity model, i.e., it yielded a higher adjusted R2 value(0.379) than the traditional gravity model result(0.259). Our study also suggests that, in addition to urban-regional and metropolitan development, the complementarities of the basic functions of cities at the administrative and market levels, as well as the corporeal and immaterial levels, play very significant roles in the characterization of city contact. Given the complexity of city contact, it will be necessary to consider more relevant influential factors in the modified gravity model to characterize the features of city contact in the future.
基金supported by the Nature Science Foundation of China(41572178)
文摘The Pearl River Delta (PRD) is located in the north coast area of the South China Sea (SCS). As one of the largest delta in China, only the two latest events among the several tens of eustatic fluctuations occurring in the Quaternary were recorded in almost whole area of the PRD.
基金The Strategic Priority Research Program of the Chinese Academy of Sciences No.XDA11010404the National Natural Science Foundation of China under contract Nos 41375096,41175079 and 41405082the Macao Meteorological and Geophysical Bureau Project under contract No.9231048
文摘Projections of potential submerged area due to sea level rise are helpful for improving understanding of the influence of ongoing global warming on coastal areas. The Ensemble Empirical Mode Decomposition method is used to adaptively decompose the sea level time series in order to extract the secular trend component. Then the linear relationship between the global mean sea level (GMSL) change and the Zhujiang (Pearl) River Delta (PRD) sea level change is calculated: an increase of 1.0 m in the GMSL corresponds to a 1.3 m (uncertainty interval from 1.25 to 1.46 m) increase in the PRD. Based on this relationship and the GMSL rise projected by the Coupled Model Intercomparison Project Phase 5 under three greenhouse gas emission scenarios (representative concentration pathways, or RCPs, from low to high emission scenarios RCP2.6, RCP4.5, and RCP8.5), the PRD sea level is calculated and projected for the period 2006-2100. By around the year 2050, the PRD sea level will rise 0.29 (0.21 to 0.40) m under RCP2.6, 0.31 (0.22 to 0.42) m under RCP4.5, and 0.34 (0.25 to 0.46) m under RCP8.5, respectively. By 2100, it will rise 0.59 (0.36 to 0.88) m, 0.71 (0.47 to 1.02) m, and 1.0 (0.68 to 1.41) m, respectively. In addition, considering the extreme value of relative sea level due to land subsidence (i.e., 0.20 m) and that obtained from intermonthly variability (i.e., 0.33 m), the PRD sea level will rise 1.94 m by the year 2100 under the RCP8.5 scenario with the upper uncertainty level (i.e., 1.41 m). Accordingly, the potential submerged area is 8.57x103 km2 for the PRD, about 1.3 times its present area.
基金Project(2008ZA11) supported by State Key Laboratory of Subtropical Building Science in South China University of Technology, ChinaProject(20080430815) supported by China Postdoctoral Science Foundation
文摘A series of researches were carried out for the soil samples in the Pearl River Delta under the action of consolidation loads,such as the quantitative analyses of the pore scale,shape and size distributions of micro-structure units,with an environmental scanning electron microscope (ESEM),a mercury intrusion analyzer and a mineral diffractometer. The experimental results show that the consolidation pressures remarkably change the pore sizes and distribution characteristics of the silt,thus changing its compressibility and permeability. This can be proved by the fact that,in the earlier stage with a consolidation pressure of p<200 kPa,the pore sizes are greater and the compressibility and permeability coefficients are larger. However,they rapidly decrease with the increase in consolidation pressure. And in the later stage with a consolidation pressure of p>200 kPa,the pore sizes are smaller and the compressibility and permeability coefficients are less. Therefore,the empirical formulas of compression coefficient and permeability coefficient vs consolidation load and average pore diameter are deduced.
基金Under the auspices of National Natural Science Foundation of China (No.41171108)Knowledge Innovation Programs of Chinese Academy of Sciences (No.KZCXZ-YW-Q10-4-1)Project of National Science and Technology Infrastructure Program (No.2008BAH31B05)
文摘The growth of peripheral ports to dominant hubs has been well documented in North America and Europe,and has led to the elaboration of several theoretical models.However,although changes in containerization growth have been taking place in the South and East Asia in recent years,particularly in China,only a few studies have fo-cused on this region.The Pearl(Zhujiang) River Delta(PRD) has a typical port system with hub and peripheral ports,and provides an excellent case for studying the Peripheral Challenge.This paper introduces the theoretical evidence of the Hayuth model and analyzes the evolution of the container port system in the PRD with five phases:1) phase I:preconditions for change and phase II:initial container port development in the 1970s and early 1980s;2) phase III:diffusion,consolidation,and port concentration in the middle and late 1980s;3) phase IV:the load center in the 1990s;and(4) phase V:the Peripheral Challenge since the late 1990s.The results illustrate that the Shenzhen port presents mounting challenges to the Hong Kong port,descending from a transshipment hub of China to a regional load center of Southeast China.Furthermore,this paper explores five points that have led to the evolution of the port system in the PRD:1) competition in the regional port systems;2) different interested parties;3) shift of investment strategies of in-ternational terminal operators;4) integration of shipping networks and reorganization of carriers;and 5) cost-based competition.
基金supported by National Social Science Fund(Grant No. 06&ZD038)The 11th Five-Year Planning programme of philosophy and Social Science of Guangdong(Grant NO.07D04)
文摘A reasonable coordination degree assessment of the social-economic development level and the resource-environment quality level are essential to ident the key factory of the development, and vital to determine the appropriate development strategy and achieve sustainable development. The major function oriented zoning plays a role in spatial coordination mainly' by spatial guidance and restriction, so. the proposal of major function oriented zoning gives a new train of thought to generate a coordination evaluation of economy-society and the resource-environment system, From the view of major function oriented zoning that considers resource environmental bearing capacity, existing development density and development potential, this paper constructs an index system and model of coordination evahtation with a case study on Pearl River Delta. The results have shown: (I) It can reveal the conflicts of economic-social development and resource-environment quality to ac- curately consider resource environmental bearing capacity, existing development densio~ and development po- tential; (2) The coordination degree between social-economy system and resource-environment system in Pearl River Delta continued to decline in the past 10 years. The spatial extent of coordination evoh,es.from coordina- tion in the whole Pearl River Delta to imbalance in the core areas, and at present, the uncoordinated areas have already diffused from core areas to the outlying regions: (3) Most regions of the Pearl River Delta are in uncoordinated condition When considering the coordination degree of economic-social development and resollrceenvironment quality, not as coordinated as some scholars considered.
基金This work was supported by the National Natural Science Foundation of Guangdong Province as key project (S201202 0011044) and Public Sector (Meteorological) Scientific Research Project (GYHY201406031). It was also partly supported by the Jiangsu Collabora- tive Innovation Center for Climate Change and Specialized Research Fund for the Doctoral Program of Higher Education in China.
文摘Understanding essential for formulating the trends in PM2.5 levels is 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 SO24 show a similar trend, increasing before 2005 and then decreasing slightly. The annual average PM2.5 concentra- tion ranges from 49.1 μg·m-3 in 2000 to 64.3 μg·m-3 in 2010, with a peak of 84.1 μg· m3 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 SO2/4 are 13.0, 6.5, and 11.8μg·m-3, respectively. NO3 and NH+ respectively have concentrations of 1.5 μg·m-3 and 2.9 μg·m-3 in 2000 and 6.4 μg·m 3 and 5.3μg·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 SO2/4- 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.
基金Foundation item: Under the auspices of National Natural Science Foundation of China (No. 40125003, No. 40601029)Natural Science Foundation of Guangdong Province (No. 06300790)
文摘As the Central Place Theory indicates, the centricity of a central city can influence the extension of its ser- vice. Since the service industry in the theory is mostly consumer services, it is worth studying the relationship between the producer services and the centricity of the city in the service society with producer services becoming a more im- portant part of the service industry. The paper takes the case of the Zhujiang (Pearl) River Delta (PRD), a developed region in China, to study the relationship between the developing level of producer services and the urban hierarchy. Based on the analysis about the spatial difference of the producer services in the nine cities of the PRD, and the divi- sion of the nine cities according to some economic indices, it is shown that there is a correlation between the develop- ing level of producer services and the urban hierarchy. Furthermore, two deductions about the future status of the pro- ducer services in the city and the location of the producer services in a large region can be made from this correlation between the developing level of producer services and the urban hierarchy.