Spatially Heterogeneous Response of Carbon Storage to Land Use Changes in Pearl River Delta Urban Agglomeration, China

Carbon storage of terrestrial ecosystems plays a vital role in advancing carbon neutrality. Better understanding of how land use changes affect carbon storage in urban agglomeration will provide valuable guidance for policymakers in developing effective regional conservation policies. Taking the Pearl River Delta Urban Agglomeration(PRDUA) in China as an example, we examined the heterogeneous response of carbon storage to land use changes in 1990–2018 from a combined view of administrative units and physical entities. The results indicate that the primary change in land use was due to the expansion of construction land(5897.16 km2). The carbon storage in PRDUA decreased from 767.34 Tg C in 1990 to 725.42 Tg C in 2018 with a spatial pattern of high wings and the low middle. The carbon storage loss was largely attributed to construction land expansion(55.74%), followed by forest degradation(54.81%). Changes in carbon storage showed significant divergences in different sized cities and hierarchical boundaries. The coefficients of geographically weighted regression(GWR) reveal that the alteration in carbon storage in Guangzhou City was more responsive to changes in construction land(-0.11) compared to other cities, while that in Shenzhen was mainly affected by the dynamics of forest land(8.32). The change in carbon storage was primarily influenced by the conversion of farmland within urban extent(5.05) and the degradation of forest land in rural areas(5.82). Carbon storage changes were less sensitive to the expansion of construction land in the urban center, urban built-up area, and ex-urban built-up area, with the corresponding GWR coefficients of 0.19, 0.04, and 0.02. This study necessitates the differentiated protection strategies of carbon storage in urban agglomerations.

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.

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.

Thirty Vears Road,Integrating a Megacity——Economic Changes inthe Yangtze River Delta Over the Past 30 Years

As one of the most dynamic economic zones in China, the Yangtze River Delta has further increased its economic output,becoming more open to foreign investment and international cooperation over the past 30 years.Its economic stability and coordination have been strengthened;and the process of regional integration continues to accelerate.

Regional Economic Growth and Spillover Effects:An Analysis of China's Pan Pearl River Delta Area

The Pan Pearl River Delta （PPRD） Regional Co-operation Framework Agreement was signed in 2004. It aims to bring prosperity through partnership among nine Chinese Mainland provinces and China ＂s two special administrative regions. In this paper, we use a dynamic panel data model to examine the economic growth of the PPRD economies from 1985 to 2009. Our analysis confirms the existence of regional growth spillover effects in the PPRD area. Our results also show that economic growth spillover effects of non-PPRD regions on the PPRD regions are greater than those among the PPRD members themselves. These findings imply that economic integration between Chinese provinces has generated considerable spillover effects on regional growth. However, the anticipated benefits of the implementation of the PPRD agreement have not been realized thus far. Therefore, greater effort shouM be made to promote further economic integration among these members so that their local economies can benefit from the positive spillover effects.

粤港澳大湾区建设对区域市场一体化程度的影响研究

为探究区域战略变动对周边区域市场一体化程度的影响,文章以粤港澳大湾区建设准自然实验法替换了常见的时间序列检验,基于双重差分模型考察了粤港澳大湾区建设对所在珠三角地区市场一体化程度的影响。研究发现,粤港澳大湾区建设能显著促进珠三角地区的市场一体化发展。文章据此提出,应该进一步推动粤港澳大湾区战略的实施,同时要进一步加强区域间协作。

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。

2008-2020年泛珠三角区域大气氨排放清单及分布特征

精确的区域氨排放清单编制对于制定有效的空气污染控制措施至关重要.以福建省、江西省、湖南省、广东省、广西壮族自治区、海南省、四川省、贵州省、云南省等9省份为研究区域,基于10种不同氨排放源活动水平数据,采用排放因子法建立了泛珠三角区域2008−2020年的氨排放清单,并利用ArcGIS软件对2020年研究区的氨排放量进行1 km×1 km空间网格分配.结果表明:①2008−2020年泛珠三角区域氨排放量为2685.40×10^(3)~2839.35×10^(3) t,总体较为稳定,年变化率在−1.42%~1.88%之间,农业源占氨排放总量的92.23%~93.79%,非农业源贡献率为6.21%~7.77%.②2020年,四川省氨排放量最大,为689.07×10^(3) t,占研究区氨排放总量的24.53%;其次为云南省和湖南省,贡献率分别为14.70%和13.90%.蛋鸡、肉牛和生猪是畜禽养殖氨排放主要贡献源,其氨排放量分别为661.75×10^(3)、339.88×10^(3)和310.97×10^(3) t.尿素占氮肥施用氨排放量的97.17%.③2020年,泛珠三角区域氨排放呈显著的空间分布差异,高值区主要集中在四川省中部地区,排放强度高达481.03 t/km^(2);低值区主要位于四川省西部和云南省西北部区域.④在95%置信区间上,2020年研究区氨排放量的不确定度范围为−18.08%~20.97%,其中畜禽养殖和燃料燃烧的不确定度较低,分别为−7.43%~8.15%和−9.50%~10.32%.研究显示,泛珠三角区域历年氨排放趋势总体变化较小,以畜禽养殖排放源为主,加强畜牧业氨减排技术的积极推广和普遍实施将是显著削减氨排放的实现途径.

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。

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.

创新人才集聚、产业结构优化与经济高质量发展——基于长三角地区41个城市的实证研究

随着我国经济迈向高质量发展阶段,各地区对创新人才的需求不断增强。结合2011—2020年中国长三角地区41个城市的统计数据,采用固定效应分析方法,探究创新人才集聚、产业结构优化对长三角地区经济高质量发展的影响。研究发现,创新人才集聚与产业结构高级化融合对经济高质量发展的促进效应更强。通过异质性分析发现,创新人才集聚能显著推动江苏省、安徽省及大城市经济的高质量发展,但对浙江省和中小城市经济的推动作用不显著;产业结构优化及其与创新人才集聚的融合对江苏省经济的促进效应优于浙江省和安徽省,对大城市经济的推动作用大于中小城市。基于门槛效应模型的研究发现,创新人才集聚对经济高质量发展的促进作用随着产业结构优化水平的提高而逐渐增强。为更好地实现区域经济高质量发展的目标,各城市有必要提高创新人才与产业结构的适配性,通过完善人才引进制度和产业体系,提高浙江省和安徽省的人才储备质量和产业水平,从而推动长三角一体化高质量发展。

长三角体育旅游一体化发展:逻辑、困境与策略

运用文献资料、专家访谈、实地考察等方法,探讨长三角体育旅游一体化发展的逻辑、困境与策略。长三角体育旅游一体化发展逻辑:资源边界共生奠定基础,经济空间扩展推升协同,“正外部”效应激发内生动力。困境:产业融合驱动乏力,数字赋能亟待提升,区域治理支撑薄弱,生态低碳融入不足。策略:深化体育旅游融合,激发新动能;夯实平台与数据支撑,引领数字赋能;完善协同与法治治理,促进治理升级;强化绿色低碳发展,赋予新内涵。

中国特色的城市群一体化的政策引领模式研究——基于珠三角与长株潭城市群的案例分析

党的二十大报告明确提出“以城市群、都市圈为依托构建大中小城市协调发展格局,推进以县城为重要载体的城镇化建设”。“城市群”作为推动经济增长的重要地域单元和空间载体,伴随着我国经济的快速发展不断地形成壮大。各个城市单位经济联系紧密、基础设施互联互通、资源要素便捷流动,最终实现区域高度一体化与同城化是城市群的本质特征和发展的内在要求。受行政区划的影响,我国的城市群被省际和市际等各类行政边界所切割,城市群协同发展机制仍需进一步优化,为各城市强化联动发展保驾护航,为城市群实现高质量发展夯实基础。因此,国家“十四五”规划明确提出了“建立健全城市群一体化协调发展机制和成本共担、利益共享机制,统筹推进基础设施协调布局、产业分工协作、公共服务共享、生态共建环境共治”的要求,从政策层面上为城市群一体化的发展明确了方向。立足我国特殊的国情和体制特点,以及城市群发展中的行政主导、规划引领的现实,政策驱动成为我国城市群一体化发展的重要力量。以行政强力协调、规划引领显著、内在联系紧密的珠三角及长株潭城市群作为城市群内部一体化发展的典型案例进行比较研究,提炼出具有鲜明中国特色的城市群一体化发展经验,致力于寻找政策引领模式下我国城市群一体化发展的有效途径。

上海建设国际经济中心升级版的战略思路研究

到2035年,上海的国际经济中心地位应与中国经济的全球新地位相匹配,在经济基础支撑力、市场主体聚集力、高端产业引领力、发展新动能孵育力、资源要素配置力、消费中心辐射力等各方面,建设成为领先全球的国际经济中心,并在引领上海都市圈和长三角一体化发展中发挥更大作用。

新发展格局下广东引领泛珠三角区域经济发展与要素流通研究

在构建以国内大循环为主体、国内国际双循环相互促进的新发展格局的过程中,推动要素自由流动是核心,加强区域经济合作则是重要的切入点。广东作为泛珠三角中经济最强的省份,不仅是要素聚集中心,也是经济动力的源泉,在泛珠三角区域发挥增长极的作用。从生产要素和产业结构两个视角进行实证分析,研究表明广东省对泛珠三角区域的经济辐射带动机制应通过自然资源、劳动力、资本、技术等要素的集聚和配置,同时发挥其在制造业、批发零售业和金融业的区位优势,推进产业转移并优化产业链结构,在泛珠三角区域形成完整的产业链、技术扩散链和市场分工链。研究提出“政府推动,市场主导”引导促进生产要素的区域流动,发展壮大实体经济规模增强要素聚集配置功能,加强区域通道体系建设增强集聚扩散效应的四点政策建议。

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。

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。