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

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

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

Understanding 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.

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.

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.

Measuring coordination of economy-society and resource-environment based on major function oriented zoning: a case study of Pearl River Delta

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.

基于改进三维生态足迹模型的珠江—西江经济带生态补偿价值测度及分区研究

生态补偿机制构建难点在于厘清补偿主客体、评估补偿优先时序及精准测算补偿标准,构建科学有效的生态补偿机制有助于流域上下游生态保护责任合理分配。本文以珠江—西江经济带地级市为研究单元,将改进三维生态足迹模型与生态系统服务价值估算相结合,测度2005—2020年各市生态补偿价值与标准,引入生态补偿优先级,最终划定优先支付、潜力支付、平衡、潜力受偿及优先受偿5类分区。结果表明:1)2020年经济带生态补偿赤字为288.09亿元,广州支付价值最高为185.14亿元,人均生态补偿标准为987.92元,仅崇左获生态补偿,受偿价值为0.68亿元,人均受偿标准为32.62元。2)广州、佛山与南宁长期为优先支付区;崇左长期为优先受偿区;肇庆、柳州及百色近年转为潜力支付区;来宾、贵港、梧州与云浮为平衡区;经济带优先受偿区与潜力受偿区逐步转为优先支付区、潜力支付区与平衡区。3)广州、佛山及南宁应率先支付生态补偿平衡经济带区际生态保护责任,协调区际生态保护共治关系;应优先给予崇左生态补偿以实现生态保护受益,获得生态环境治理的经济支持。

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.

长三角地区传统村落空间分布及其影响因素研究

以长三角地区41个地市2012-2022年间评选的1255个传统村落为研究对象,采用核密度分析、标准差椭圆和随机森林回归等方法,分析传统村落空间演化规律及影响因素。研究结果表明:长三角地区传统村落空间分布不均衡,在苏浙皖交界处分布集中,形成了西北-东南方向的空间分布格局;少数民族人口比例对传统村落密度的正向影响最为明显,路网密度、人口密度、农业生产总值、城镇化率、财政支出和游客周转量等影响因子与传统村落密度间大多表现为负向关系;从影响因素来看,长三角地区传统村落的形成演化是地理条件、社会经济和历史文化交互耦合作用的结果。该研究能为长三角地区传统村落保护与开发和乡村振兴发展提供科学依据和理论参考。

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。

珠江-西江经济带耕地集约利用与生态安全协调发展研究

协调好耕地集约利用与耕地生态安全之间的关系,是实现耕地可持续利用的必然选择。本研究通过构建珠江-西江经济带耕地集约利用与生态安全协调发展评价指标体系,分析2011-2020年珠江-西江经济带11个市的耕地集约利用与生态安全协调发展情况。研究表明,在时间上,珠江-西江经济带的耕地集约利用和生态安全协调发展度总体上呈逐年上升趋势,但广东段有3个市呈波动下降趋势,广西段各市均达到勉强协调发展和初级协调发展;在空间上,珠江-西江经济带各市的协调发展度存在着明显的地区性差异。研究结果可为珠江-西江经济带各市提高耕地集约利用水平、耕地集约利用与生态安全协调发展提供参考和新的发展思路。

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。

珠三角城市群用水量与经济增长的脱钩状态及其驱动因素研究

减轻经济增长对水资源消耗的依赖,对实现城市的可持续发展至关重要。以珠江三角洲城市群为研究对象,从整体和城市两个维度分析其水资源负载状况,采用Tapio脱钩模型分析2009-2019年经济增长与用水量的脱钩时空变化特征,并基于LMDI分解法探究影响因素的驱动效应。结果表明:研究期内珠三角城市群水资源负载较高,除肇庆、惠州、江门3市外,其他6市水资源负载等级均达到Ⅴ级;珠三角城市群强、弱脱钩状态占比为98.9%,部分城市则呈现强、弱脱钩交替状态;技术效应、产业结构、节水能力是珠三角城市群脱钩的主要驱动因素,单位水资源效益、人口规模则抑制了脱钩。本研究可为减少城市经济增长对水资源的依赖、实现区域可持续发展提供参考。

珠三角区域经济发展差异及空间溢出效应研究

经济发展的区域差异与不平衡是经济增长过程中的普遍现象。广东省作为我国经济第一大省,其内部亦有着经济发展的区域差异与不平衡现象。在广东省提出打造环珠江口一百公里黄金内湾的背景下,本文利用珠三角地区九个城市2001年至2022年的面板数据,建立空间杜宾模型,实证分析了资本存量、劳动力、人均财政支出、第二产业增加值、第三产业增加值、进出口总额、外商直接投资等关键经济因素对区域内总体经济的空间溢出效应,并根据实证的主要结论,有针对性地提出了相关的建议。

从共建到共赢:长三角开发区合作的经济效应研究

作为地区经济增长极和推动高质量发展的主要载体,开发区近年来备受学界关注。文章基于长三角开发区合作共建的背景,采用空间计量模型研究了长三角地区具有共建关系的开发区经济绩效增长特征,以及共建关系对经济绩效增长的影响机制。结果表明:第一,开发区共建有利于实现经济共赢。第二,在共建开发区中,高发展水平开发区之间的学习效应较强,经济增长的同步特征明显;低发展水平开发区具有持续的“向上学习”特征,有利于强化经济增长的同步效应。第三,基于共建关系形成的招商合作有利于双方经济增长,而税收合作与土地合作对共建双方经济增长效应具有较强的不确定性。上述研究对于各大城市群从开发区合作共建角度开展区域一体化建设,进而实现共同富裕具有重要意义。

珠三角城市群城间生态缓冲区的空间分布与林分特征分析

研究从珠三角城市群城间尺度出发,识别并筛选出城间生态缓冲区共54个,分析其空间分布及林分结构特征等指标。结果表明:(1)珠三角城市群内城间生态缓冲区数量较多,面积多在200~1000 hm^(2),但分布不均,主要集中在东莞—深圳—惠州以及中山—珠海—江门的城间交界处;(2)城间生态缓冲区的整体斑块形状不规则,且破碎化程度较高;(3)城间生态缓冲区的林分结构不够合理。纯林占比较高,树种组成单一;人工林占比偏高,达80.6%,但林分生产力低下,且单位面积蓄积量明显低于全国人工林水平;年龄结构不合理,同龄林和中幼龄林比重较大;生态公益林占比偏低,为50.79%,森林质量整体偏低。因此,未来珠三角城市群城间生态缓冲区的建设应注重空间分布的均衡性,斑块形状的规则性与连续性,以及林分结构的合理性。

珠江三角洲园镇融合研究——以狮山和松山湖为例

以珠江三角洲地区佛山狮山镇和东莞松山湖为例,利用广东省2015年土地利用数据和两个城市2016年社会经济数据,从空间结构融合、城镇化发展质量与管理体制整合等方面,分析园镇融合的特点和模式,并探讨园镇融合发展的内外动力机制,得到如下结论。1)园镇融合是产城融合在村镇尺度上的一种形式,其内涵包括体制整合、空间与功能融合以及城镇化发展。2)狮山采取园镇合一逐步更新发展模式,空间上核心带动组团发展;松山湖则采取新区统筹规划的发展模式,形成功能分区组团发展空间结构。3)园镇系统受到内外部动力共同作用,融合发展,其中外部动力包括全球化、土地财政和国家区域政策调整。作为统筹力、发展力和支撑力,制度、产业和城镇化要素构成推动园镇融合的系统内部动力。4)作为主要的外部动力承担者与内部动力实施者,地方政府主导园镇发展。狮山在镇域尺度重构制度、产业和城镇化要素,推动逐步融合;松山湖基于统筹规划、利用制度与产业集群的地方化以及高质量的城镇化来促进园镇融合发展。狮山和松山湖的园镇融合改变了珠江三角洲村镇原有城乡混合、粗放型的发展模式,推动“产-城-人”相协调的城乡融合发展。

珠三角经济高质量发展水平测度和空间特征

珠三角地区是我国经济从高速发展阶段到高质量发展阶段的重要示范区域之一。从“创新、协调、绿色、开放、共享”5大维度,构建25项具体指标的评价体系,采用熵值法和地理信息系统,对2014—2019年珠三角的经济高质量发展进行水平测度和空间特征分析。结果发现:珠三角地区经济高质量发展综合得分的均值变化较小,且呈小幅上涨趋势;除了开放维度呈现明显下降趋势,其他4个指标均有着不同态势的波动增长;经济高质量发展等级表现优异的是深圳、珠海、广州,沿海城市的综合得分普遍较高,整体空间分布大致呈“M”形格局。

珠三角城间生态缓冲区生态服务功能及影响因素

城间生态缓冲区具有净化污染、降低生态危害的作用,是森林城市群的特色指标之一。以珠三角森林城市群为例,选定典型城间生态缓冲区为试验区域,基于实地调查和林分清查,分析城间生态缓冲区森林生态服务功能及其影响因素。结果表明:1)珠三角城间生态缓冲区具有降低温度、消减颗粒物(PM_(2.5)、PM_(10))、丰富负氧离子等生态服务功能。2)城间生态缓冲区降温效应与平均胸径、平均树高存在显著(P<0.05)正相关;PM_(2.5)和PM_(10)消减效应与LAI呈不显著(P>0.05)正相关;丰富负氧离子能力与平均胸径、平均树高极显著(P<0.01)正相关,与郁闭度显著(P<0.05)正相关。综上可知,城间生态缓冲区所具备的生态服务功能与平均胸径、平均树高指标密切相关,因此,城间生态缓冲区建设宜种植树体高大、树冠茂盛的林木。

2016一2020年珠三角城市群生态环境状况时空演变及其社会经济影响因素分析

生态环境质量影响城市群社会经济的协调发展。文章以珠三角城市群为研究区域,依据原环境保护部发布的《生态环境状况评价技术规范》(HJ192-2015),分析2016-2020年珠三角城市群生态环境状况变化特征及其影响因素。结果表明,2016-2020年珠三角城市生态环境状况总体良好,生态环境状况指数(EI)保持在59.6~85.0;珠三角城市群EI与城市化率、农林牧渔业总产值、人口密度、工业总产值和电力消费量均呈显著相关关系。