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.

The Middle-aged and Knowledge Workers: Demographic and Economic Changes in the Pearl River Delta, China

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.

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.

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

Dongguan City, located in the Pearl River Delta economic zone of China, is famous for its rapid developing township-enterprises in the past 30 years. A total of 759 composite soil samples, including 606 surface soil samples and 153 deep soil samples, have been collected in the city. These samples have been analyzed for 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.

Analysis of the Higher Education Research in the Chengdu-Chongqing Region:A Comparative Perspective Based on Three Major Economic Circles in China

Drawing on literature regarding higher education research retrieved from the CNKI database from 1997 to 2021,this paper used CiteSpace to analyze the current status of higher education research in the Chengdu-Chongqing economic circle.By comparing it with that in the Beijing-Tianjin-Hebei region,the Guangdong-Hong Kong-Macao Greater Bay Area,and the Yangtze River Delta,this paper concluded that the level of higher education research within a region is in line with the level of the region’s economic and social development.As higher education research in the Chengdu-Chongqing economic circle draws more and more attention,its research areas and topics are becoming increasingly diversified.However,by comparison,the research in this region features a late start and lower participation of researchers and research institutions,resulting in insufficient research in both quantity and quality.Therefore,it is essential to encourage more experts and scholars to participate in higher education research in the Chengdu-Chongqing economic circle.Efforts should also be made to strengthen academic exchanges and cooperation between scholars in Chengdu and Chongqing and establish a long-term cooperation mechanism for higher education research between the two cities.Improved higher education research will definitely facilitate the construction of first-class universities,thus providing human capital and intellectual support for the construction of the Chengdu-Chongqing economic circle.

Urban shrinkage and growth: Measurement and determinants of economic resilience in the Pearl River Delta

In the aftermath of the global financial crisis of 2008, China witnessed gradual shrinkage of cities in the Pearl River Delta(PRD). In this study, we introduce the concept of economic resilience to analyse urban growth and shrinkage in the context of a rapidly-urbanising region. Multiple regression analysis is performed to explore the determinants of economic resilience in the PRD. By measuring resistance in the shrinking phase and recoverability in the growing phase in a group of cities in the PRD, this study distinguishes four scenarios and investigates their characteristics from a spatial perspective. The results demonstrate that the financial crisis had a severe and asymmetric influence on this area, indicating more than 15% of cities are faced with shrinking. The spatial distribution of economic resilience indicates a centre-periphery pattern, that is, high economic resilience in the inner ring and low economic resilience in the outer ring of the PRD. The service economy is found to play a significant role in promoting urban economic resilience. Results imply that sound economic policies for enhancing resilience: both poor local financial status and a high degree of export concentration adversely impact resistance, while upgrading the manufacturing economy and stimulating of industrial innovation are conducive to improve recoverability.

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

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.

基于企业组织关系的珠三角城市群数字经济关联格局研究

运用连锁网络模型和社会网络分析法,基于数字经济上市企业总部-分支机构数据构建网络,分析2005—2020年珠三角城市群数字经济关联格局。结果显示:1) 2005—2020年珠三角城市群数字经济上市企业数量增长迅猛,企业跨城市联系增强,深圳、广州是数字经济发展的引擎和关联网络的控制中心。2)城市群整体关联结构从2005年的广-珠-深及连线城市组成的单三角形转变为2020年的广-佛-深和广-珠-深及连线城市组成的双三角形,网络密度提升,不对称性减弱,由单区域中心向多区域中心转变。3)分行业看,数字经济发展的行业间差距明显,信息传输、软件和信息技术服务业的网络联系最强,金融业最弱,制造业居中,深圳、广州双核心地位凸显,肇庆、江门位于网络边缘。4)推动城市群数字经济持续健康发展,需进一步增强城市间数字经济合作,更好地发挥核心城市的辐射带动作用,完善边缘城市的数字经济发展政策和基础设施;在细分行业上统筹规划行业布局,促进各行业均衡发展,形成数字经济发展合力。

成渝地区双城经济圈与长三角一体化发展产业创新协作:难点、成因及优化路径

区域协调发展战略是党中央作出的重大战略部署。实现成渝地区双城经济圈和长三角一体化发展两大国家区域重大战略的产业创新协作是落实区域协调发展战略的重要举措之一。从区域发展水平、产业创新载体和产业创新主体等视角探讨两大区域产业创新协作的难点和障碍,并从体制机制、政策体系、营商环境和要素配置等方面分析成因。最后,提出实施产业创新协作六大工程、加强产业发展协同联动、提升产业“四链”融合质效和打造产业创新协作共同体等优化产业创新协作的路径。

经济一体化对韶关市经济转型发展的实证研究

韶关市地处粤北欠发达地区,通过积极融入泛珠三角经济一体化来促进自身发展。本文利用韶关市相关数据,对重要经济指标及其增长率进行了统计分析,并对粤北和广东省进行了对比研究。结果表明,得益于经济一体化战略,韶关市的经济从绝对数来看取得了长足发展,但从增长率来看发展则相对滞后。这说明经济一体化对欠发达城市具有双重效应,也给政府在政策设计和协同方面带来更大的挑战。

制造业与生产性服务业耦合协同能提高经济圈竞争力吗?——基于京津冀与长三角两大经济圈的比较

本文基于系统耦合度模型,通过建立相应的指标体系,具体测度了我国长三角和京津冀两大经济圈制造业与生产性服务业的耦合协调度与区域制造业竞争力水平,进而实证分析和比较了两大经济圈制造业与生产性服务业耦合协调度对区域制造业竞争力的影响及其机理。研究结果显示:两大经济圈制造业与生产性服务业耦合协调度对区域制造业竞争力具有明显提升作用,这种作用在两大经济圈之间以及各个经济圈内部各省市之间存在一定的差别。总体上看,两大经济圈应进一步促进生产性服务业发展,提高其与制造业之间的耦合协调水平,以提升区域制造业竞争力水平。

基于多元统计和傅立叶和谱分析的土壤重金属的来源解析及其风险评价

分析珠江三角洲腹地佛山顺德区208个蔬菜地表层土样Cu、Ni、Cr、As、Pb、Zn、Cd和Hg等8种重金属的全量,结果表明,8种重金属的平均浓度高于广东省土壤背景值。Cd和Hg的最高浓度和变异系数分别为6.54mg/kg、115%和4.82mg/kg、151%,暗示Cd和Hg的人为来源。多元统计与傅立叶和谱分析的结合,解释了Cr、Ni和Cu的自然来源,Pb、Zn、As、Cd和Hg的人为来源;傅立叶和谱分析进一步阐释了Zn与Cu的双重来源,并推断土壤Hg来源于大气沉降。研究区内大约21.7%的土壤受重金属污染,表明需要调整该区的农业生产活动。

珠江三角洲经济区水资源可持续利用初步评价

在中国和世界上最活跃的经济区———珠江三角洲经济区各市社会经济发展预测的基础上 ,计算了该区各市 2 0 0 2年、2 0 1 0年和 2 0 2 0年各行业需水量和水资源供需平衡状况 ,提出了水资源质量损失系数和水资源承载力 (相对承载力 )指数等概念和计算方法 ,评价了各市水资源承载力的趋势 ,认为三角洲用水问题严重 ,尤其是东莞、深圳和广州 ,其水资源承载力较其他城市弱。并指出了工业结构性缺水、生活水质性缺水和工程性缺水等三大问题和矛盾 ,提出了建议水资源可持续利用的 3种模式 :外引型模式、外调型模式、内调型模式。研究认为 ,珠江三角洲经济区的水资源要得到合理的持续利用 ,应当有流域内部和跨流域的通力合作与协作 ,包括与邻区、邻省和港澳之间的合作与协作。除了供水之外 ,防洪、航运、压咸、发电等功能也不可忽视 ,用系统工程来解决水资源可持续利用问题是一个很好的途径。

珠江三角洲经济区可持续发展中的水环境问题

对珠江三角洲经济区水环境现状和污染源进行了分析 ,指出生活污染是当前最大的污染源 .首次提出了用于宏观评价水资源承载力和水环境可持续性的“水资源质量损失系数”、“水资源质量修复系数”和“水资源质量损失量”的概念及计算方法 ,据此预算了 2 0 0 2、2 0 10和 2 0 2 0年珠江三角洲经济区水资源净损失量分别达 0 95、1 41和 1 70亿m3 ,相当于该区约 73 4、10 1 4和 116 2万人口年生活用水总量 .各市现状水环境质量优劣排序是江门、肇庆、惠州、佛山、深圳、珠海、广州。

珠江三角洲经济区河水中微量元素的空间分布

在珠江三角洲经济区采集了29个河水样品,利用高分辨率仪器ICP MS测量了河水中微量元素的含量。结果表明,河水中稀土元素的平均含量按西江、北江、珠三角河、深圳河、东江的顺序呈增加趋势;珠三角河及深圳河具有较高重金属含量,西江和北江中重金属含量相对较低,东江居中。经分析发现,珠江三角洲经济区河水中微量元素的空间分布特征是自然条件和人类活动共同作用的结果;自然环境对稀土元素的空间分布起主要作用;人类活动是影响重金属分布特征不可忽视的重要因素。

珠江三角洲的双轨城市化

讨论中国在改革时期双轨城市化兴起的政治经济因素。随后分析双轨城市化在珠江三角洲的趋势及其对空间发展的含义。1980-1990年代,城市化有扩散的倾向,但同时又选择性地集中在新发展的经济特区。但是,此后珠三角出现了国家主导的城市化在主要的城市中心集中的新趋势。本文所展示的复杂现实,对现有基于城市或小城镇的城市化理论提出了挑战。

珠江三角洲经济区主要城市不同功能区大气气溶胶中优控多环芳烃污染评价

以WHO的苯并(a)芘标准和珠江三角洲经济区大气气溶胶中优控多环芳烃春季区域性背景为依据 ,对区内主要城市中不同功能区大气气溶胶中优控多环芳烃的污染程度进行了评价。结果表明 ,在相同的功能区 ,冬春季节大气气溶胶中多环芳烃含量及污染程度较夏季的高 ;同为冬春季节 ,商业、居民集中和交通复合功能区的PAHs污染最为严重 ,交通或居民集中单一功能区次之 ,工业区较轻 ;同为夏季 ,工业区的PAHs污染程度较大 ,而商业或交通单一功能区较小。还提出了一个尝试性多参数公式。并建议在常规大气环境监测的基础上 。

京津冀、长三角、珠三角人口分布的社会经济协调性及区域差异对比研究

作为我国主要的人口集聚地和社会经济发展的重要增长极,京津冀、长三角、珠三角的人口与社会经济的协调发展是我国实现可持续发展的关键问题之一。本文建立人口分布的社会经济协调度模型,从城市群、分地市、分县3个尺度,定量揭示并对比分析了三大城市群人口分布的社会经济协调程度、区域差异与空间格局,研究表明:长三角人口分布的社会经济协调度最高,地市差异最小,长三角、珠三角、京津冀的社会经济协调度县域优良率分别为100%、97.92%和87.10%,讨论并提出了其形成机制与政策建议。

“深港创新圈”发展及其推动珠三角产业转型升级研究

分析"深港创新圈"的发展基础,研究其发展优势,提出如何发挥"深港创新圈"核心节点作用,推动珠三角产业转型升级的对策建议。

产业承接地评价模型及应用研究——以广东省为例

运用区域分析方法,对广东省珠三角经济区以外的各个县区进行综合分析,建立评价指标体系,并运用主成分分析方法确定各指标权重,通过评价模型进行适宜度和优势度评价。结果显示,在珠三角经济区以外的80个县区中,有14个县区为最优产业承接地,另有22个县区适宜承接产业转移,这些地区不仅资源环境条件优越,还具备较好的发展基础。其中粤西地区是优选产业承接地最集中的地区;粤东则是另一集中地,尤其是汕头市,该市除海岛县——南澳外,其余县区均列为优选产业承接地;粤北地区由于生态环境相对脆弱,是三大区域中优选产业承接地比例最低的区域,今后的发展仍应以保护生态环境为主。